TY - JOUR A1 - Zupok, Arkadiusz A1 - Iobbi-Nivol, Chantal A1 - Mejean, Vincent A1 - Leimkühler, Silke T1 - The regulation of Moco biosynthesis and molybdoenzyme gene expression by molybdenum and iron in bacteria JF - Metallomics : integrated biometal science N2 - Bacterial molybdoenzymes are key enzymes involved in the global sulphur, nitrogen and carbon cycles. These enzymes require the insertion of the molybdenum cofactor (Moco) into their active sites and are able to catalyse a large range of redox-reactions. Escherichia coli harbours nineteen different molybdoenzymes that require a tight regulation of their synthesis according to substrate availability, oxygen availability and the cellular concentration of molybdenum and iron. The synthesis and assembly of active molybdoenzymes are regulated at the level of transcription of the structural genes and of translation in addition to the genes involved in Moco biosynthesis. The action of global transcriptional regulators like FNR, NarXL/QP, Fur and ArcA and their roles on the expression of these genes is described in detail. In this review we focus on what is known about the molybdenum- and iron-dependent regulation of molybdoenzyme and Moco biosynthesis genes in the model organism E. coli. The gene regulation in E. coli is compared to two other well studied model organisms Rhodobacter capsulatus and Shewanella oneidensis. Y1 - 2019 U6 - https://doi.org/10.1039/c9mt00186g SN - 1756-5901 SN - 1756-591X VL - 11 IS - 10 SP - 1602 EP - 1624 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Zupok, Arkadiusz A1 - Górka, Michał Jakub A1 - Siemiatkowska, Beata A1 - Skirycz, Aleksandra A1 - Leimkühler, Silke T1 - Iron-Dependent Regulation of Molybdenum Cofactor Biosynthesis Genes in Escherichia coli JF - Journal of bacteriology N2 - Molybdenum cofactor (Moco) biosynthesis is a complex process that involves the coordinated function of several proteins. In recent years it has become obvious that the availability of iron plays an important role in the biosynthesis of Moco. First, the MoaA protein binds two (4Fe-4S] clusters per monomer. Second, the expression of the moaABCDE and moeAB operons is regulated by FNR, which senses the availability of oxygen via a functional NFe-4S) cluster. Finally, the conversion of cyclic pyranopterin monophosphate to molybdopterin requires the availability of the L-cysteine desulfurase IscS, which is a shared protein with a main role in the assembly of Fe-S clusters. In this report, we investigated the transcriptional regulation of the moaABCDE operon by focusing on its dependence on cellular iron availability. While the abundance of selected molybdoenzymes is largely decreased under iron-limiting conditions, our data show that the regulation of the moaABCDE operon at the level of transcription is only marginally influenced by the availability of iron. Nevertheless, intracellular levels of Moco were decreased under iron-limiting conditions, likely based on an inactive MoaA protein in addition to lower levels of the L-cysteine desulfurase IscS, which simultaneously reduces the sulfur availability for Moco production. IMPORTANCE FNR is a very important transcriptional factor that represents the master switch for the expression of target genes in response to anaerobiosis. Among the FNR-regulated operons in Escherichia coli is the moaABCDE operon, involved in Moco biosynthesis. Molybdoenzymes have essential roles in eukaryotic and prokaryotic organisms. In bacteria, molybdoenzymes are crucial for anaerobic respiration using alternative electron acceptors. This work investigates the connection of iron availability to the biosynthesis of Moco and the production of active molybdoenzymes. KW - Escherichia coli KW - FNR KW - iron regulation KW - iron-sulfur cluster KW - anaerobic respiration KW - molybdenum cofactor Y1 - 2019 U6 - https://doi.org/10.1128/JB.00382-19 SN - 0021-9193 SN - 1098-5530 VL - 201 IS - 17 PB - American Society for Microbiology CY - Washington ER - TY - JOUR A1 - Zimmermann, Heike Hildegard A1 - Harms, Lars A1 - Epp, Laura Saskia A1 - Mewes, Nick A1 - Bernhardt, Nadine A1 - Kruse, Stefan A1 - Stoof-Leichsenring, Kathleen Rosemarie A1 - Pestryakova, Luidmila Agafyevna A1 - Wieczorek, Mareike A1 - Trense, Daronja A1 - Herzschuh, Ulrike T1 - Chloroplast and mitochondrial genetic variation of larches at the Siberian tundrataiga ecotone revealed by de novo assembly JF - PLoS one N2 - Larix populations at the tundra-taiga ecotone in northern Siberia are highly under-represented in population genetic studies, possibly due to the remoteness of these regions that can only be accessed at extraordinary expense. The genetic signatures of populations in these boundary regions are therefore largely unknown. We aim to generate organelle reference genomes for the detection of single nucleotide polymorphisms (SNPs) that can be used for paleogenetic studies. We present 19 complete chloroplast genomes and mitochondrial genomic sequences of larches from the southern lowlands of the Taymyr Peninsula (northernmost range of Larix gmelinii (Rupr.) Kuzen.), the lower Omoloy River, and the lower Kolyma River (both in the range of Larix cajanderi Mayr). The genomic data reveal 84 chloroplast SNPs and 213 putatively mitochondrial SNPs. Parsimony-based chloroplast haplotype networks show no spatial structure of individuals from different geographic origins, while the mitochondrial haplotype network shows at least a slight spatial structure with haplotypes from the Omoloy and Kolyma populations being more closely related to each other than to most of the haplotypes from the Taymyr populations. Whole genome alignments with publicly available complete chloroplast genomes of different Larix species show that among official plant barcodes only the rcbL gene contains sufficient polymorphisms, but has to be sequenced completely to distinguish the different provenances. We provide 8 novel mitochondrial SNPs that are putatively diagnostic for the separation of L. gmelinii and L. cajanderi, while 4 chloroplast SNPs have the potential to distinguish the L. gmelinii/ L. cajanderi group from other Larix species. Our organelle references can be used for a targeted primer and probe design allowing the generation of short amplicons. This is particularly important with regard to future investigations of, for example, the biogeographic history of Larix by screening ancient sedimentary DNA of Larix. Y1 - 2019 U6 - https://doi.org/10.1371/journal.pone.0216966 SN - 1932-6203 VL - 14 IS - 7 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Zhang, Yunming A1 - Ramming, Anna A1 - Heinke, Lisa A1 - Altschmied, Lothar A1 - Slotkin, R. Keith A1 - Becker, Jörg D. A1 - Kappel, Christian A1 - Lenhard, Michael T1 - The poly(A) polymerase PAPS1 interacts with the RNA-directed DNA-methylation pathway in sporophyte and pollen development JF - The plant journal N2 - RNA-based processes play key roles in the regulation of eukaryotic gene expression. This includes both the processing of pre-mRNAs into mature mRNAs ready for translation and RNA-based silencing processes, such as RNA-directed DNA methylation (RdDM). Polyadenylation of pre-mRNAs is one important step in their processing and is carried out by three functionally specialized canonical nuclear poly(A) polymerases in Arabidopsis thaliana. Null mutations in one of these, termed PAPS1, result in a male gametophytic defect. Using a fluorescence-labelling strategy, we have characterized this defect in more detail using RNA and small-RNA sequencing. In addition to global defects in the expression of pollen-differentiation genes, paps1 null-mutant pollen shows a strong overaccumulation of transposable element (TE) transcripts, yet a depletion of 21- and particularly 24-nucleotide-long short interfering RNAs (siRNAs) and microRNAs (miRNAs) targeting the corresponding TEs. Double-mutant analyses support a specific functional interaction between PAPS1 and components of the RdDM pathway, as evident from strong synergistic phenotypes in mutant combinations involving paps1, but not paps2 paps4, mutations. In particular, the double-mutant of paps1 and rna-dependent rna polymerase 6 (rdr6) shows a synergistic developmental phenotype disrupting the formation of the transmitting tract in the female gynoecium. Thus, our findings in A. thaliana uncover a potentially general link between canonical poly(A) polymerases as components of mRNA processing and RdDM, reflecting an analogous interaction in fission yeast. KW - poly(A) polymerase KW - RNA-directed DNA methylation KW - pollen development KW - siRNAs KW - transposable elements KW - gynoecium development KW - Arabidopsis thaliana Y1 - 2019 U6 - https://doi.org/10.1111/tpj.14348 SN - 0960-7412 SN - 1365-313X VL - 99 IS - 4 SP - 655 EP - 672 PB - Wiley CY - Hoboken ER - TY - THES A1 - Zhang, Xiaorong T1 - Electrosynthesis and characterization of molecularly imprinted polymers for peptides and proteins Y1 - 2019 ER - TY - JOUR A1 - Zhang, Shuhao A1 - Bramski, Julia A1 - Tutus, Murat A1 - Pietruszka, Jörg A1 - Böker, Alexander A1 - Reinicke, Stefan T1 - A Biocatalytically Active Membrane Obtained from Immobilization of 2-Deoxy-D-ribose-5-phosphate Aldolase on a Porous Support JF - ACS applied materials & interfaces N2 - Aldol reactions play an important role in organic synthesis, as they belong to the class of highly beneficial C-C-linking reactions. Aldol-type reactions can be efficiently and stereoselectively catalyzed by the enzyme 2-deoxy-D-ribose-5-phosphate aldolase (DERA) to gain key intermediates for pharmaceuticals such as atorvastatin. The immobilization of DERA would open the opportunity for a continuous operation mode which gives access to an efficient, large-scale production of respective organic intermediates. In this contribution, we synthesize and utilize DERA/polymer conjugates for the generation and fixation of a DERA bearing thin film on a polymeric membrane support. The conjugation strongly increases the tolerance of the enzyme toward the industrial relevant substrate acetaldehyde while UV-cross-linkable groups along the conjugated polymer chains provide the opportunity for covalent binding to the support. First, we provide a thorough characterization of the conjugates followed by immobilization tests on representative, nonporous cycloolefinic copolymer supports. Finally, immobilization on the target supports constituted of polyacrylonitrile (PAN) membranes is performed, and the resulting enzymatically active membranes are implemented in a simple membrane module setup for the first assessment of biocatalytic performance in the continuous operation mode using the combination hexanal/acetaldehyde as the substrate. KW - 2-deoxy-D-ribose-5-phoshphate aldolase KW - enzyme immobilization KW - enzymatically active membrane KW - enzyme/polymer conjugate KW - self-assembly Y1 - 2019 U6 - https://doi.org/10.1021/acsami.9b12029 SN - 1944-8244 SN - 1944-8252 VL - 11 IS - 37 SP - 34441 EP - 34453 PB - American Chemical Society CY - Washington ER - TY - THES A1 - Zemella, Anne T1 - Fluoreszenzmarkierung und Modifizierung von komplexen Proteinen in eukaryotischen zellfreien Systemen durch die Etablierung von orthogonalen tRNA/Aminoacyl-tRNA-Synthetase-Paaren T1 - Fluorescent labeling and modification of complex proteins in eukaryotic cell-free systems by establishing orthogonal tRNA/aminoacyl-tRNA-synthetase pairs N2 - Die funktionelle Charakterisierung von therapeutisch relevanten Proteinen kann bereits durch die Bereitstellung des Zielproteins in adäquaten Mengen limitierend sein. Dies trifft besonders auf Membranproteine zu, die aufgrund von zytotoxischen Effekten auf die Produktionszelllinie und der Tendenz Aggregate zu bilden, in niedrigen Ausbeuten an aktivem Protein resultieren können. Der lebende Organismus kann durch die Verwendung von translationsaktiven Zelllysaten umgangen werden- die Grundlage der zellfreien Proteinsynthese. Zu Beginn der Arbeit wurde die ATP-abhängige Translation eines Lysates auf der Basis von kultivierten Insektenzellen (Sf21) analysiert. Für diesen Zweck wurde ein ATP-bindendes Aptamer eingesetzt, durch welches die Translation der Nanoluziferase reguliert werden konnte. Durch die dargestellte Applizierung von Aptameren, könnten diese zukünftig in zellfreien Systemen für die Visualisierung der Transkription und Translation eingesetzt werden, wodurch zum Beispiel komplexe Prozesse validiert werden können. Neben der reinen Proteinherstellung können Faktoren wie posttranslationale Modifikationen sowie eine Integration in eine lipidische Membran essentiell für die Funktionalität des Membranproteins sein. Im zweiten Abschnitt konnte, im zellfreien Sf21-System, für den G-Protein-gekoppelten Rezeptor Endothelin B sowohl eine Integration in die endogen vorhandenen Endoplasmatisch Retikulum-basierten Membranstrukturen als auch Glykosylierungen, identifiziert werden. Auf der Grundlage der erfolgreichen Synthese des ET-B-Rezeptors wurden verschiedene Methoden zur Fluoreszenzmarkierung des Adenosin-Rezeptors A2a (Adora2a) angewandt und optimiert. Im dritten Abschnitt wurde der Adora2a mit Hilfe einer vorbeladenen tRNA, welche an eine fluoreszierende Aminosäure gekoppelt war, im zellfreien Chinesischen Zwerghamster Ovarien (CHO)-System markiert. Zusätzlich konnte durch den Einsatz eines modifizierten tRNA/Aminoacyl-tRNA-Synthetase-Paares eine nicht-kanonische Aminosäure an Position eines integrierten Amber-Stopcodon in die Polypeptidkette eingebaut und die funktionelle Gruppe im Anschluss an einen Fluoreszenzfarbstoff gekoppelt werden. Aufgrund des offenen Charakters eignen sich zellfreie Proteinsynthesesysteme besonders für eine Integration von exogenen Komponenten in den Translationsprozess. Mit Hilfe der Fluoreszenzmarkierung wurde eine ligandvermittelte Konformationsänderung im Adora2a über einen Biolumineszenz-Resonanzenergietransfer detektiert. Durch die Etablierung der Amber-Suppression wurde darüber hinaus das Hormon Erythropoetin pegyliert, wodurch Eigenschaften wie Stabilität und Halbwertszeit des Proteins verändert wurden. Zu guter Letzt wurde ein neues tRNA/Aminoacyl-tRNA-Synthetase-Paar auf Basis der Methanosarcina mazei Pyrrolysin-Synthetase etabliert, um das Repertoire an nicht-kanonischen Aminosäuren und den damit verbundenen Kopplungsreaktionen zu erweitern. Zusammenfassend wurden die Potenziale zellfreier Systeme in Bezug auf der Herstellung von komplexen Membranproteinen und der Charakterisierung dieser durch die Einbringung einer positionsspezifischen Fluoreszenzmarkierung verdeutlicht, wodurch neue Möglichkeiten für die Analyse und Funktionalisierung von komplexen Proteinen geschaffen wurden. N2 - The functional characterization of therapeutically relevant proteins can be limited due to the provision of the target protein in adequate amounts. In particular membrane proteins belong to the so called “difficult-to-express” proteins because of possible cytotoxic side effects and a susceptibility to aggregation. The living organism can be circumvented by using cell lysates – the basic for cell-free protein synthesis. In the beginning of the thesis the ATP-dependent translation process in a cell lysate based on cultured insect (Sf21) cells was analyzed. For this purpose the translation of a nanoluciferase was regulated by the addition of an ATP-binding aptamer. The demonstrated application of aptamers in cell-free systems might enable a visualization of transcription and translation and following a potential validation process for high-throughput syntheses. In addition to the protein synthesis, factors such as posttranslational modifications and a correct integration into a lipid membrane are essential for the functionality of membrane proteins. Therefore, in the second part, integration of the G protein-coupled Endothelin receptor type B (ET-B) into the endogenous endoplasmic reticulum derived membranes and glycosylation were shown to be possible in a Sf21 cell-free system. Following to the successful synthesis of the ET-B receptor different fluorescent labeling strategies were applied to the adenosine receptor A2a (Adora2a). The first strategy applied precharged tRNAs, coupled to a fluorescently labeled amino acid, to the translation process in a Chinese Hamster Ovary cells (CHO) cell-free system. The second strategy utilized a modified tRNA/aminoacyl-tRNA-synthetase pair to incorporate a non-canonical amino acid at an integrated amber stop codon with a subsequently fluorescent labeling. The open character of cell-free systems enables a feasible integration of exogenous components into the translation process. The site-specific fluorescent labeling was the basis for the detection of a ligand-induced conformational change in the Adora2a by a bioluminescence resonance energy transfer. Additionally the amber suppression technique was transferred to the hormone Erythropoietin (EPO) to modify EPO´s stability and half-life period by coupling polyethylene glycol. Last but not least a novel tRNA/aminoacyl-tRNA-synthetase pair based on the Methanosarcina mazei pyrrolysine synthetase was developed to further increase the repertoire of non-canonical amino acids and copper-free click reactions. Summarizing in the present thesis the potentials of cell-free protein systems related to the synthesis of “difficult-to-express” proteins and the characterization of these proteins with site-specific fluorescence labeling are depicted, thereby establishing new methods for the analysis and functionalization of complex proteins. KW - Zellfreie Proteinsynthese KW - nicht-kanonische Aminosäuren KW - Klick-Chemie KW - Fluoreszenzmarkierung KW - GPCRs KW - Proteinmodifizierung KW - cell-free protein synthesis KW - non-canonical amino acids KW - click chemistry KW - fluorescent labeling KW - GPCRs KW - protein modification Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-442361 ER - TY - JOUR A1 - Zeitler, Stefanie A1 - Ye, Lian A1 - Andreyeva, Aksana A1 - Schumacher, Fabian A1 - Monti, Juliana A1 - Nürnberg, Bernd A1 - Nowak, Gabriel A1 - Kleuser, Burkhard A1 - Reichel, Martin A1 - Fejtova, Anna A1 - Kornhuber, Johannes A1 - Rhein, Cosima A1 - Friedland, Kristina T1 - Acid sphingomyelinase - a regulator of canonical transient receptor potential channel 6 (TRPC6) activity JF - Journal of neurochemistry N2 - Recent investigations propose the acid sphingomyelinase (ASM)/ceramide system as a novel target for antidepressant action. ASM catalyzes the breakdown of the abundant membrane lipid sphingomyelin to the lipid messenger ceramide. This ASM‐induced lipid modification induces a local shift in membrane properties, which influences receptor clustering and downstream signaling. Canonical transient receptor potential channels 6 (TRPC6) are non‐selective cation channels located in the cell membrane that play an important role in dendritic growth, synaptic plasticity and cognition in the brain. They can be activated by hyperforin, an ingredient of the herbal remedy St. John’s wort for treatment of depression disorders. Because of their role in the context of major depression, we investigated the crosstalk between the ASM/ceramide system and TRPC6 ion channels in a pheochromocytoma cell line 12 neuronal cell model (PC12 rat pheochromocytoma cell line). Ca2+ imaging experiments indicated that hyperforin‐induced Ca2+ influx through TRPC6 channels is modulated by ASM activity. While antidepressants, known as functional inhibitors of ASM activity, reduced TRPC6‐mediated Ca2+ influx, extracellular application of bacterial sphingomyelinase rebalanced TRPC6 activity in a concentration‐related way. This effect was confirmed in whole‐cell patch clamp electrophysiology recordings. Lipidomic analyses revealed a decrease in very long chain ceramide/sphingomyelin molar ratio after ASM inhibition, which was connected with changes in the abundance of TRPC6 channels in flotillin‐1–positive lipid rafts as visualized by western blotting. Our data provide evidence that the ASM/ceramide system regulates TRPC6 channels likely by controlling their recruitment to specific lipid subdomains and thereby fine‐tuning their physical properties. KW - acid sphingomyelinase KW - antidepressants KW - ceramide KW - hyperforin KW - lipid rafts KW - TRPC6 Y1 - 2019 U6 - https://doi.org/10.1111/jnc.14823 SN - 0022-3042 SN - 1471-4159 VL - 150 IS - 6 SP - 678 EP - 690 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Yuan, Jun-Xia A1 - Hou, Xin-Dong A1 - Barlow, Axel A1 - Preick, Michaela A1 - Taron, Ulrike H. A1 - Alberti, Federica A1 - Basler, Nikolas A1 - Deng, Tao A1 - Lai, Xu-Long A1 - Hofreiter, Michael A1 - Sheng, Gui-Lian T1 - Molecular identification of late and terminal Pleistocene Equus ovodovi from northeastern China JF - PLOS ONE N2 - The extant diversity of horses (family Equidae) represents a small fraction of that occurring over their evolutionary history. One such lost lineage is the subgenus Sussemionus, which is thought to have become extinct during the Middle Pleistocene. However, recent molecular studies and morphological analysis have revealed that one of their representatives, E. ovodovi, did exist in Siberia during the Late Pleistocene. Fossil materials of E. ovodovi have thus far only been found in Russia. In this study, we extracted DNA from three equid fossil specimens excavated from northeastern China dated at 12,770-12,596, 29,525-28,887 and 40,201-38,848 cal. yBP, respectively, and retrieved three near-complete mitochondrial genomes from the specimens. Phylogenetic analyses cluster the Chinese haplotypes together with previously published Russian E. ovodovi, strongly supporting the assignment of these samples to this taxon. The molecular identification of E. ovodovi in northeastern China extends the known geographical range of this fossil species by several thousand kilometers to the east. The estimated coalescence time of all E. ovodovi haplotypes is approximately 199 Kya, with the Chinese haplotypes coalescing approximately 130 Kya. With a radiocarbon age of 12,770-12,596 cal. yBP, the youngest sample in this study represents the first E. ovodovi sample dating to the terminal Pleistocene, moving the extinction date of this species forwards considerably compared to previously documented fossils. Overall, comparison of our three mitochondrial genomes with the two published ones suggests a genetic diversity similar to several extant species of the genus Equus. Y1 - 2019 U6 - https://doi.org/10.1371/journal.pone.0216883 SN - 1932-6203 VL - 14 IS - 5 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Yu, Yanjun A1 - Wu, Shenjie A1 - Nowak, Jacqueline A1 - Wang, Guangda A1 - Han, Libo A1 - Feng, Zhidi A1 - Mendrinna, Amelie A1 - Ma, Yinping A1 - Wang, Huan A1 - Zhang, Xiaxia A1 - Tian, Juan A1 - Dong, Li A1 - Nikoloski, Zoran A1 - Persson, Staffan A1 - Kong, Zhaosheng T1 - Live-cell imaging of the cytoskeleton in elongating cotton fibres JF - Nature plants N2 - Cotton (Gossypium hirsutum) fibres consist of single cells that grow in a highly polarized manner, assumed to be controlled by the cytoskeleton(1-3). However, how the cytoskeletal organization and dynamics underpin fibre development remains unexplored. Moreover, it is unclear whether cotton fibres expand via tip growth or diffuse growth(2-4). We generated stable transgenic cotton plants expressing fluorescent markers of the actin and microtubule cytoskeleton. Live-cell imaging revealed that elongating cotton fibres assemble a cortical filamentous actin network that extends along the cell axis to finally form actin strands with closed loops in the tapered fibre tip. Analyses of F-actin network properties indicate that cotton fibres have a unique actin organization that blends features of both diffuse and tip growth modes. Interestingly, typical actin organization and endosomal vesicle aggregation found in tip-growing cell apices were not observed in fibre tips. Instead, endomembrane compartments were evenly distributed along the elongating fibre cells and moved bi-directionally along the fibre shank to the fibre tip. Moreover, plus-end tracked microtubules transversely encircled elongating fibre shanks, reminiscent of diffusely growing cells. Collectively, our findings indicate that cotton fibres elongate via a unique tip-biased diffuse growth mode. Y1 - 2019 U6 - https://doi.org/10.1038/s41477-019-0418-8 SN - 2055-026X SN - 2055-0278 VL - 5 IS - 5 SP - 498 EP - 504 PB - Nature Publ. Group CY - London ER - TY - THES A1 - Yishai, Oren T1 - Engineering the reductive glycine pathway in Escherichia coli Y1 - 2019 ER - TY - JOUR A1 - Yang, Lei A1 - Perrera, Valentina A1 - Saplaoura, Eleftheria A1 - Apelt, Federico A1 - Bahin, Mathieu A1 - Kramdi, Amira A1 - Olas, Justyna Jadwiga A1 - Müller-Röber, Bernd A1 - Sokolowska, Ewelina A1 - Zhang, Wenna A1 - Li, Runsheng A1 - Pitzalis, Nicolas A1 - Heinlein, Manfred A1 - Zhang, Shoudong A1 - Genovesio, Auguste A1 - Colot, Vincent A1 - Kragler, Friedrich T1 - m(5)C Methylation Guides Systemic Transport of Messenger RNA over Graft Junctions in Plants JF - Current biology N2 - In plants, transcripts move to distant body parts to potentially act as systemic signals regulating development and growth. Thousands of messenger RNAs (mRNAs) are transported across graft junctions via the phloem to distinct plant parts. Little is known regarding features, structural motifs, and potential base modifications of transported transcripts and how these may affect their mobility. We identified Arabidopsis thalianam RNAs harboring the modified base 5-methylcytosine (m(5)C) and found that these are significantly enriched in mRNAs previously described as mobile, moving over graft junctions to distinct plant parts. We confirm this finding with graft-mobile methylated mRNAs TRANSLATIONALLY CONTROLLED TUMOR PROTEIN 1 (TCTP1) and HEAT SHOCK COGNATE PROTEIN 70.1 (HSC70.1), whose mRNA transport is diminished in mutants deficient in m(5)C mRNA methylation. Together, our results point toward an essential role of cytosine methylation in systemic mRNA mobility in plants and that TCTP1 mRNA mobility is required for its signaling function. Y1 - 2019 U6 - https://doi.org/10.1016/j.cub.2019.06.042 SN - 0960-9822 SN - 1879-0445 VL - 29 IS - 15 SP - 2465 EP - 2476.e5 PB - Cell Press CY - Cambridge ER - TY - JOUR A1 - Yan, Wenhao A1 - Chen, Dijun A1 - Schumacher, Julia A1 - Durantini, Diego A1 - Engelhorn, Julia A1 - Chen, Ming A1 - Carles, Cristel C. A1 - Kaufmann, Kerstin T1 - Dynamic control of enhancer activity drives stage-specific gene expression during flower morphogenesis JF - Nature Communications N2 - Enhancers are critical for developmental stage-specific gene expression, but their dynamic regulation in plants remains poorly understood. Here we compare genome-wide localization of H3K27ac, chromatin accessibility and transcriptomic changes during flower development in Arabidopsis. H3K27ac prevalently marks promoter-proximal regions, suggesting that H3K27ac is not a hallmark for enhancers in Arabidopsis. We provide computational and experimental evidence to confirm that distal DNase. hypersensitive sites are predictive of enhancers. The predicted enhancers are highly stage-specific across flower development, significantly associated with SNPs for flowering-related phenotypes, and conserved across crucifer species. Through the integration of genome-wide transcription factor (TF) binding datasets, we find that floral master regulators and stage-specific TFs are largely enriched at developmentally dynamic enhancers. Finally, we show that enhancer clusters and intronic enhancers significantly associate with stage-specific gene regulation by floral master TFs. Our study provides insights into the functional flexibility of enhancers during plant development, as well as hints to annotate plant enhancers. Y1 - 2019 U6 - https://doi.org/10.1038/s41467-019-09513-2 SN - 2041-1723 VL - 10 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Yamamichi, Masato A1 - Klauschies, Toni A1 - Miner, Brooks E. A1 - van Velzen, Ellen T1 - Modelling inducible defences in predator-prey interactions BT - assumptions and dynamical consequences of three distinct approaches JF - Ecology letters N2 - Inducible defences against predation are widespread in the natural world, allowing prey to economise on the costs of defence when predation risk varies over time or is spatially structured. Through interspecific interactions, inducible defences have major impacts on ecological dynamics, particularly predator-prey stability and phase lag. Researchers have developed multiple distinct approaches, each reflecting assumptions appropriate for particular ecological communities. Yet, the impact of inducible defences on ecological dynamics can be highly sensitive to the modelling approach used, making the choice of model a critical decision that affects interpretation of the dynamical consequences of inducible defences. Here, we review three existing approaches to modelling inducible defences: Switching Function, Fitness Gradient and Optimal Trait. We assess when and how the dynamical outcomes of these approaches differ from each other, from classic predator-prey dynamics and from commonly observed eco-evolutionary dynamics with evolving, but non-inducible, prey defences. We point out that the Switching Function models tend to stabilise population dynamics, and the Fitness Gradient models should be carefully used, as the difference with evolutionary dynamics is important. We discuss advantages of each approach for applications to ecological systems with particular features, with the goal of providing guidelines for future researchers to build on. KW - Adaptive dynamics KW - fitness gradient KW - inducible defence KW - optimal trait KW - phenotypic plasticity KW - predator-prey dynamics KW - reaction norm KW - switching function Y1 - 2019 U6 - https://doi.org/10.1111/ele.13183 SN - 1461-023X SN - 1461-0248 VL - 22 IS - 2 SP - 390 EP - 404 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Wu, Hao A1 - Han, Yijie A1 - Rodriguez Sillke, Yasmina A1 - Deng, Hongzhang A1 - Siddiqui, Sophiya A1 - Treese, Christoph A1 - Schmidt, Franziska A1 - Friedrich, Marie A1 - Keye, Jacqueline A1 - Wan, Jiajia A1 - Qin, Yue A1 - Kühl, Anja A. A1 - Qin, Zhihai A1 - Siegmund, Britta A1 - Glauben, Rainer T1 - Lipid droplet-dependent fatty acid metabolism controls the immune suppressive phenotype of tumor-associated macrophages JF - EMBO molecular medicine N2 - Tumor-associated macrophages (TAMs) promote tumor growth and metastasis by suppressing tumor immune surveillance. Herein, we provide evidence that the immunosuppressive phenotype of TAMs is controlled by long-chain fatty acid metabolism, specifically unsaturated fatty acids, here exemplified by oleate. Consequently, en-route enriched lipid droplets were identified as essential organelles, which represent effective targets for chemical inhibitors to block in vitro polarization of TAMs and tumor growth in vivo. In line, analysis of human tumors revealed that myeloid cells infiltrating colon cancer but not gastric cancer tissue indeed accumulate lipid droplets. Mechanistically, our data indicate that oleate-induced polarization of myeloid cells depends on the mammalian target of the rapamycin pathway. Thus, our findings reveal an alternative therapeutic strategy by targeting the pro-tumoral myeloid cells on a metabolic level. KW - cancer immunotherapy KW - lipid droplets KW - lipid metabolism KW - tumor microenvironment KW - tumor-associated macrophage Y1 - 2019 U6 - https://doi.org/10.15252/emmm.201910698 SN - 1757-4676 SN - 1757-4684 VL - 11 IS - 11 PB - Wiley CY - Hoboken ER - TY - THES A1 - Wozniak, Natalia Joanna T1 - Convergent evolution of the selfing syndrome in the genus Capsella BT - inferring the genetic basis and evolutionary history of selfing syndrome traits Y1 - 2019 ER - TY - JOUR A1 - Witzel, Katja A1 - Abu Risha, Marua A1 - Albers, Philip A1 - Börnke, Frederik A1 - Hanschen, Franziska S. T1 - Identification and Characterization of Three Epithiospecifier Protein Isoforms in Brassica oleracea JF - Frontiers in plant science N2 - Glucosinolates present in Brassicaceae play a major role in herbivory defense. Upon tissue disruption, glucosinolates come into contact with myrosinase, which initiates their breakdown to biologically active compounds. Among these, the formation of epithionitriles is triggered by the presence of epithiospecifier protein (ESP) and a terminal double bond in the glucosinolate side chain. One ESP gene is characterized in the model plant Arabidopsis thaliana (AtESP; At1g54040.2). However, Brassica species underwent genome triplication since their divergence from the Arabidopsis lineage. This indicates the presence of multiple ESP isoforms in Brassica crops that are currently poorly characterized. We identified three B. oleracea ESPs, specifically BoESP1 (LOC106296341), BoESP2 (LOC106306810), and BoESP3 (LOC106325105) based on in silico genome analysis. Transcript and protein abundance were assessed in shoots and roots of four B. oleracea vegetables, namely broccoli, kohlrabi, white, and red cabbage, because these genotypes showed a differential pattern for the formation of glucosinolate hydrolysis products as well for their ESP activity. BoESP1 and BoESP2 were expressed mainly in shoots, while BoESP3 was abundant in roots. Biochemical characterization of heterologous expressed BoESP isoforms revealed different substrate specificities towards seven glucosinolates: all isoforms showed epithiospecifier activity on alkenyl glucosinolates, but not on non-alkenyl glucosinolates. The pH-value differently affected BoESP activity: while BoESP1 and BoESP2 activities were optimal at pH 6-7, BoESP3 activity remained relatively stable from pH 4 to 7. In order test their potential for the in vivo modification of glucosinolate breakdown, the three isoforms were expressed in A. thaliana Hi-0, which lacks AtESP expression, and analyzed for the effect on their respective hydrolysis products. The BoESPs altered the hydrolysis of allyl glucosinolate in the A. thaliana transformants to release 1-cyano-2,3-epithiopropane and reduced formation of the corresponding 3-butenenitrile and allyl isothiocyanate. Plants expressing BoESP2 showed the highest percentage of released epithionitriles. Given these results, we propose a model for isoform-specific roles of B. oleracea ESPs in glucosinolate breakdown. KW - epithionitrile KW - expression profile KW - functional complementation KW - glucosinolate hydrolysis KW - nitrile KW - specifier proteins KW - tissue specificity Y1 - 2019 U6 - https://doi.org/10.3389/fpls.2019.01552 SN - 1664-462X VL - 10 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Wiebke, Ullmann T1 - Warum hat Bayern mehr Feldhasen als Brandenburg? JF - Vielfalt in der Uckermark : Forschungsprojekte 2015 - 2018 Y1 - 2019 SP - 46 EP - 47 PB - oerding print GmbH CY - Braunschweig ER - TY - JOUR A1 - Werchmeister, Rebecka Maria Larsen A1 - Tang, Jing A1 - Xiao, Xinxin A1 - Wollenberger, Ulla A1 - Hjuler, Hans Aage A1 - Ulstrup, Jens A1 - Zhang, Jingdong T1 - Three-Dimensional Bioelectrodes Utilizing Graphene Based Bioink JF - Journal of The Electrochemical Society N2 - Enzyme immobilization using nanomaterials offers new approaches to enhanced bioelectrochemical performance and is essential for the preparation of bioelectrodes with high reproducibility and low cost. In this report, we describe the development of new three-dimensional (3D) bioelectrodes by immobilizing a "bioink" of glucose oxidase (GOD) in a matrix of reduced graphene oxides (RGOs), polyethylenimine (PEI), and ferrocene carboxylic acid (FcCOOH) on carbon paper (CP). CP with 3D interwoven carbon fibers serves as a solid porous and electronically conducting skeleton, providing large surface areas and space for loading the bioink and diffusion of substrate molecules, respectively. RGO enhances contact between the GOD-matrix and CP, maintaining high conductivity. The composition of the bioink has been systematically optimized. The GOD bioelectrodes show linearly increasing electrocatalytic oxidation current toward glucose concentration up to 48 mM. A hybrid enzymatic biofuel cell equipped with the GOD bioelectrode as a bioanode and a platinum cathode furthermore registers a maximum power density of 5.1 mu W cm(-2) and an open circuit voltage of 0.40 V at 25 degrees C. The new method reported of preparing a bioelectrode by drop-casting the bioink onto the substrate electrode is facile and versatile, with the potential of application also for other enzymatic bioelectrodes. Y1 - 2019 U6 - https://doi.org/10.1149/2.0261916jes SN - 0013-4651 SN - 1945-7111 VL - 166 IS - 16 SP - G170 EP - G177 PB - The Electrochemical Society CY - Pennington ER - TY - JOUR A1 - Wendler, Petra A1 - Enenkel, Cordula T1 - Nuclear Transport of Yeast Proteasomes JF - Frontiers in molecular biosciences N2 - Proteasomes are key proteases in regulating protein homeostasis. Their holo-enzymes are composed of 40 different subunits which are arranged in a proteolytic core (CP) flanked by one to two regulatory particles (RP). Proteasomal proteolysis is essential for the degradation of proteins which control time-sensitive processes like cell cycle progression and stress response. In dividing yeast and human cells, proteasomes are primarily nuclear suggesting that proteasomal proteolysis is mainly required in the nucleus during cell proliferation. In yeast, which have a closed mitosis, proteasomes are imported into the nucleus as immature precursors via the classical import pathway. During quiescence, the reversible absence of proliferation induced by nutrient depletion or growth factor deprivation, proteasomes move from the nucleus into the cytoplasm. In the cytoplasm of quiescent yeast, proteasomes are dissociated into CP and RP and stored in membrane-less cytoplasmic foci, named proteasome storage granules (PSGs). With the resumption of growth, PSGs clear and mature proteasomes are transported into the nucleus by Blm10, a conserved 240 kDa protein and proteasome-intrinsic import receptor. How proteasomes are exported from the nucleus into the cytoplasm is unknown. KW - proteasome KW - nuclear transport KW - importin KW - karyopherin KW - Blm10 KW - proteasome storage granules Y1 - 2019 U6 - https://doi.org/10.3389/fmolb.2019.00034 SN - 2296-889X VL - 6 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Weiß, Lina A1 - Wulff, Monika T1 - Veränderung der Landnutzung in der nord-westlichen Uckermark von 1780 bis heute JF - Vielfalt in der Uckermark : Forschungsprojekte 2015 - 2018 Y1 - 2019 SP - 20 EP - 21 PB - oerding print GmbH CY - Braunschweig ER - TY - JOUR A1 - Weiss, Lina A1 - Schalow, Linda A1 - Jeltsch, Florian A1 - Geissler, Katja T1 - Experimental evidence for root competition effects on community evenness in one of two phytometer species JF - Journal of plant ecology N2 - Aims Plant-plant interactions, being positive or negative, are recognized to be key factors in structuring plant communities. However, it is thought that root competition may be less important than shoot competition due to greater size symmetry belowground. Because direct experimental tests on the importance of root competition are scarce, we aim at elucidating whether root competition may have direct or indirect effects on community structure. Indirect effects may occur by altering the overall size asymmetry of competition through root-shoot competitive interactions. Methods We used a phytometer approach to examine the effects of root, shoot and total competition intensity and importance on evenness of experimental plant communities. Thereby two different phytometer species, Festuca brevipila and Dianthus carthusianorum, were grown in small communities of six grassland species over three levels of light and water availability, interacting with neighbouring shoots, roots, both or not at all. Important Findings We found variation in community evenness to be best explained if root and shoot (but not total) competition were considered. However, the effects were species specific: in Dianthus communities increasing root competition increased plant community evenness, while in Festuca communities shoot competition was the driving force of this evenness response. Competition intensities were influenced by environmental conditions in Dianthus, but not in Festuca phytometer plants. While we found no evidence for root-shoot interactions for neither phytometer species root competition in Dianthus communities led to increased allocation to shoots, thereby increasing the potential ability to perform in size-asymmetric competition for light. Our experiment demonstrates the potential role of root competition in structuring plant communities. KW - plant-plant interactions KW - root and shoot competition KW - intensity vs KW - importance KW - experimental plant communities KW - asymmetry of competition Y1 - 2018 U6 - https://doi.org/10.1093/jpe/rty021 SN - 1752-9921 SN - 1752-993X VL - 12 IS - 2 SP - 281 EP - 291 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Von Raab-Straube, Eckhard A1 - Raus, Thomas A1 - Bazos, Ioannis A1 - Cornec, J. P. A1 - De Belair, Gerard. A1 - Dimitrakopoulos, P. G. A1 - El Mokni, Ridha A1 - Fateryga, Alexander V. A1 - Fateryga, Valentina V. A1 - Fridlender, Alain A1 - Gil, Jaime A1 - Grigorenko, V. N. A1 - Hand, Ralf A1 - Kovalchuk, A. A1 - Mastrogianni, A. A1 - Otto, R. A1 - Rätzel, Stefan A1 - Raus, Th. A1 - Ristow, Michael A1 - Salas Pascual, M. A1 - Strid, Arne A1 - Svirin, S. A. A1 - Tsiripidis, Ioannis. A1 - Uhlich, Holger A1 - Vela, Errol A1 - Verloove, Filip A1 - Vidakis, K. A1 - Yena, Andriy Vasylyovych A1 - Yevseyenkov, P. E. A1 - Zeddam, A. T1 - Euro plus Med-Checklist Notulae, 11 JF - Willdenowia N2 - This is the eleventh of a series of miscellaneous contributions, by various authors, where hitherto unpublished data relevant to both the Med-Checklist and the Euro+Med (or Sisyphus) projects are presented. This instalment deals with the families Anacardiaceae, Asparagaceae (incl. Hyacinthaceae), Bignoniaceae, Cactaceae, Compositae, Cruciferae, Cyperaceae, Ericaceae, Gramineae, Labiatae, Leguminosae, Orobanchaceae, Polygonaceae, Rosaceae, Solanaceae and Staphyleaceae. It includes new country and area records and taxonomic and distributional considerations for taxa in Bidens, Campsis, Centaurea, Cyperus, Drymocallis, Engem, Hoffmannseggia, Hypopitys, Lavandula, Lithraea, Melilotus, Nicotiana, Olimarabidopsis, Opuntia, Orobanche, Phelipanche, Phragmites, Rumex, Salvia, Schinus, Staphylea, and a new combination in Drimia. KW - distribution KW - Euro plus Med PlantBase KW - Europe KW - Med-Checklist KW - Mediterranean KW - new combination KW - new record KW - taxonomy KW - vascular plants Y1 - 2019 U6 - https://doi.org/10.3372/wi.49.49312 SN - 0511-9618 VL - 49 IS - 3 SP - 421 EP - 445 PB - Botanischer Garten & botanisches Museum Berlin-Dahlem CY - Berlin ER - TY - JOUR A1 - Velo-Antón, Guillermo A1 - Boratyński, Zbyszek A1 - Ferreira, Clara Mendes A1 - Lima, Vanessa O. A1 - Alves, Paulo C. A1 - Brito, José C. T1 - Intraspecific genetic diversity and distribution of North African hedgehogs (Mammalia: Erinaceidae) JF - Biological journal of the Linnean Society : a journal of evolution N2 - Despite growing efforts to halt biodiversity loss, knowledge of species diversity and distribution is highly geographically biased, leaving some areas unexplored. Taxa distributed in remote, desert areas, such as hedgehogs (Mammalia; Eulipotyphla) in North Africa, are good examples of current knowledge gaps in systematics and biogeography. Here we studied the geographical distribution and intraspecific genetic diversity of hedgehogs in North Africa. Specimens belonging to North African and Eurasian species were analysed with mitochondrial (control region, CR) and nuclear (recombination activating gene 1, RAG1) gene fragments. This revealed a broader geographical distribution of Atelerix algirus in south-western Libya and of Paraechinus aethiopicus along the Atlantic Sahara. High intraspecific genetic differentiation was found in A. algirus and A. albiventris at the mitochondrial level, with nuclear haplotype sharing across their ranges. These findings suggest that biogeographical patterns of hedgehogs in North Africa are more complex than previously suggested, highlighting a need for further investigation in this remote and poorly known area. KW - Atelerix albiventris KW - Atelerix algirus KW - conservation genetics KW - cryptic diversity KW - distribution KW - Paraechinus aethiopicus KW - Phylogeny KW - Sahara-Sahel Y1 - 2019 U6 - https://doi.org/10.1093/biolinnean/blz030 SN - 0024-4066 SN - 1095-8312 VL - 127 IS - 1 SP - 156 EP - 163 PB - Oxford University Press CY - Oxford ER - TY - THES A1 - Vandrich, Jasmina T1 - Metabolic Engineering in Halomonas elongata Y1 - 2019 ER - TY - JOUR A1 - Toulouse, Charlotte Marguerite A1 - Schmucker, Sonja A1 - Metesch, Kristina A1 - Pfannstiel, Jens A1 - Michel, Bernd A1 - Starke, Ines A1 - Möller, Heiko Michael A1 - Stefanski, Volker A1 - Steuber, Julia T1 - Mechanism and impact of catecholamine conversion by Vibrio cholerae JF - Biochimica et biophysica acta : Bioenergetics N2 - Bacterial pathogens are influenced by signaling molecules including the catecholamines adrenaline and noradrenaline which are host-derived hormones and neurotransmitters. Adrenaline and noradrenaline modulate growth, motility and virulence of bacteria. We show that adrenaline is converted by the pathogen Vibrio cholerae to adrenochrome in the course of respiration, and demonstrate that superoxide produced by the respiratory, Na+ - translocating NADH:quinone oxidoreductase (NQR) acts as electron acceptor in the oxidative conversion of adrenaline to adrenochrome. Adrenochrome stimulates growth of V. cholerae, and triggers specific responses in V. cholerae and in immune cells. We performed a quantitative proteome analysis of V. cholerae grown in minimal medium with glucose as carbon source without catecholamines, or with adrenaline, noradrenaline or adrenochrome. Significant regulation of proteins participating in iron transport and iron homeostasis, in energy metabolism, and in signaling was observed upon exposure to adrenaline, noradrenaline or adrenochrome. On the host side, adrenochrome inhibited lipopolysaccharide-triggered formation of TNF-alpha by THP-1 monocytes, though to a lesser extent than adrenaline. It is proposed that adrenochrome produced from adrenaline by respiring V. cholerae functions as effector molecule in pathogen-host interaction. KW - Vibrio cholerae KW - Na+ - NADH:quinone oxidoreductase KW - NQR KW - Superoxide KW - Adrenaline KW - Adrenochrome Y1 - 2019 U6 - https://doi.org/10.1016/j.bbabio.2019.04.003 SN - 0005-2728 SN - 1879-2650 VL - 1860 IS - 6 SP - 478 EP - 487 PB - Elsevier CY - Amsterdam ER - TY - THES A1 - Tong, Hao T1 - Dissection of genetic architecture of intermediate phenotypes and predictions in plants N2 - Determining the relationship between genotype and phenotype is the key to understand the plasticity and robustness of phenotypes in nature. While the directly observable plant phenotypes (e.g. agronomic, yield and stress resistance traits) have been well-investigated, there is still a lack in our knowledge about the genetic basis of intermediate phenotypes, such as metabolic phenotypes. Dissecting the links between genotype and phenotype depends on suitable statistical models. The state-of-the-art models are developed for directly observable phenotypes, regardless the characteristics of intermediate phenotypes. This thesis aims to fill the gaps in understanding genetic architecture of intermediate phenotypes, and how they tie to composite traits, namely plant growth. The metabolite levels and reaction fluxes, as two aspects of metabolic phenotypes, are shaped by the interrelated chemical reactions formed in genome-scale metabolic network. Here, I attempt to answer the question: Can the knowledge of underlying genome-scale metabolic network improve the model performance for prediction of metabolic phenotypes and associated plant growth? To this end, two projects are investigated in this thesis. Firstly, we propose an approach that couples genomic selection with genome-scale metabolic network and metabolic profiles in Arabidopsis thaliana to predict growth. This project is the first integration of genomic data with fluxes predicted based on constraint-based modeling framework and data on biomass composition. We demonstrate that our approach leads to a considerable increase of prediction accuracy in comparison to the state-of-the-art methods in both within and across environment predictions. Therefore, our work paves the way for combining knowledge on metabolic mechanisms in the statistical approach underlying genomic selection to increase the efficiency of future plant breeding approaches. Secondly, we investigate how reliable is genomic selection for metabolite levels, and which single nucleotide polymorphisms (SNPs), obtained from different neighborhoods of a given metabolic network, contribute most to the accuracy of prediction. The results show that the local structure of first and second neighborhoods are not sufficient for predicting the genetic basis of metabolite levels in Zea mays. Furthermore, we find that the enzymatic SNPs can capture most the genetic variance and the contribution of non-enzymatic SNPs is in fact small. To comprehensively understand the genetic architecture of metabolic phenotypes, I extend my study to a local Arabidopsis thaliana population and their hybrids. We analyze the genetic architecture in primary and secondary metabolism as well as in growth. In comparison to primary metabolites, compounds from secondary metabolism were more variable and show more non-additive inheritance patterns which could be attributed to epistasis. Therefore, our study demonstrates that heterozygosity in local Arabidopsis thaliana population generates metabolic variation and may impact several tasks directly linked to metabolism. The studies in this thesis improve the knowledge of genetic architecture of metabolic phenotypes in both inbreed and hybrid population. The approaches I proposed to integrate genome-scale metabolic network with genomic data provide the opportunity to obtain mechanistic insights about the determinants of agronomically important polygenic traits. Y1 - 2019 ER - TY - JOUR A1 - Tiegs, Scott D. A1 - Costello, David M. A1 - Isken, Mark W. A1 - Woodward, Guy A1 - McIntyre, Peter B. A1 - Gessner, Mark O. A1 - Chauvet, Eric A1 - Griffiths, Natalie A. A1 - Flecker, Alex S. A1 - Acuna, Vicenc A1 - Albarino, Ricardo A1 - Allen, Daniel C. A1 - Alonso, Cecilia A1 - Andino, Patricio A1 - Arango, Clay A1 - Aroviita, Jukka A1 - Barbosa, Marcus V. M. A1 - Barmuta, Leon A. A1 - Baxter, Colden V. A1 - Bell, Thomas D. C. A1 - Bellinger, Brent A1 - Boyero, Luz A1 - Brown, Lee E. A1 - Bruder, Andreas A1 - Bruesewitz, Denise A. A1 - Burdon, Francis J. A1 - Callisto, Marcos A1 - Canhoto, Cristina A1 - Capps, Krista A. A1 - Castillo, Maria M. A1 - Clapcott, Joanne A1 - Colas, Fanny A1 - Colon-Gaud, Checo A1 - Cornut, Julien A1 - Crespo-Perez, Veronica A1 - Cross, Wyatt F. A1 - Culp, Joseph M. A1 - Danger, Michael A1 - Dangles, Olivier A1 - de Eyto, Elvira A1 - Derry, Alison M. A1 - Diaz Villanueva, Veronica A1 - Douglas, Michael M. A1 - Elosegi, Arturo A1 - Encalada, Andrea C. A1 - Entrekin, Sally A1 - Espinosa, Rodrigo A1 - Ethaiya, Diana A1 - Ferreira, Veronica A1 - Ferriol, Carmen A1 - Flanagan, Kyla M. A1 - Fleituch, Tadeusz A1 - Shah, Jennifer J. Follstad A1 - Frainer, Andre A1 - Friberg, Nikolai A1 - Frost, Paul C. A1 - Garcia, Erica A. A1 - Lago, Liliana Garcia A1 - Garcia Soto, Pavel Ernesto A1 - Ghate, Sudeep A1 - Giling, Darren P. A1 - Gilmer, Alan A1 - Goncalves, Jose Francisco A1 - Gonzales, Rosario Karina A1 - Graca, Manuel A. S. A1 - Grace, Mike A1 - Grossart, Hans-Peter A1 - Guerold, Francois A1 - Gulis, Vlad A1 - Hepp, Luiz U. A1 - Higgins, Scott A1 - Hishi, Takuo A1 - Huddart, Joseph A1 - Hudson, John A1 - Imberger, Samantha A1 - Iniguez-Armijos, Carlos A1 - Iwata, Tomoya A1 - Janetski, David J. A1 - Jennings, Eleanor A1 - Kirkwood, Andrea E. A1 - Koning, Aaron A. A1 - Kosten, Sarian A1 - Kuehn, Kevin A. A1 - Laudon, Hjalmar A1 - Leavitt, Peter R. A1 - Lemes da Silva, Aurea L. A1 - Leroux, Shawn J. A1 - Leroy, Carri J. A1 - Lisi, Peter J. A1 - MacKenzie, Richard A1 - Marcarelli, Amy M. A1 - Masese, Frank O. A1 - Mckie, Brendan G. A1 - Oliveira Medeiros, Adriana A1 - Meissner, Kristian A1 - Milisa, Marko A1 - Mishra, Shailendra A1 - Miyake, Yo A1 - Moerke, Ashley A1 - Mombrikotb, Shorok A1 - Mooney, Rob A1 - Moulton, Tim A1 - Muotka, Timo A1 - Negishi, Junjiro N. A1 - Neres-Lima, Vinicius A1 - Nieminen, Mika L. A1 - Nimptsch, Jorge A1 - Ondruch, Jakub A1 - Paavola, Riku A1 - Pardo, Isabel A1 - Patrick, Christopher J. A1 - Peeters, Edwin T. H. M. A1 - Pozo, Jesus A1 - Pringle, Catherine A1 - Prussian, Aaron A1 - Quenta, Estefania A1 - Quesada, Antonio A1 - Reid, Brian A1 - Richardson, John S. A1 - Rigosi, Anna A1 - Rincon, Jose A1 - Risnoveanu, Geta A1 - Robinson, Christopher T. A1 - Rodriguez-Gallego, Lorena A1 - Royer, Todd V. A1 - Rusak, James A. A1 - Santamans, Anna C. A1 - Selmeczy, Geza B. A1 - Simiyu, Gelas A1 - Skuja, Agnija A1 - Smykla, Jerzy A1 - Sridhar, Kandikere R. A1 - Sponseller, Ryan A1 - Stoler, Aaron A1 - Swan, Christopher M. A1 - Szlag, David A1 - Teixeira-de Mello, Franco A1 - Tonkin, Jonathan D. A1 - Uusheimo, Sari A1 - Veach, Allison M. A1 - Vilbaste, Sirje A1 - Vought, Lena B. M. A1 - Wang, Chiao-Ping A1 - Webster, Jackson R. A1 - Wilson, Paul B. A1 - Woelfl, Stefan A1 - Xenopoulos, Marguerite A. A1 - Yates, Adam G. A1 - Yoshimura, Chihiro A1 - Yule, Catherine M. A1 - Zhang, Yixin X. A1 - Zwart, Jacob A. T1 - Global patterns and drivers of ecosystem functioning in rivers and riparian zones JF - Science Advances N2 - River ecosystems receive and process vast quantities of terrestrial organic carbon, the fate of which depends strongly on microbial activity. Variation in and controls of processing rates, however, are poorly characterized at the global scale. In response, we used a peer-sourced research network and a highly standardized carbon processing assay to conduct a global-scale field experiment in greater than 1000 river and riparian sites. We found that Earth’s biomes have distinct carbon processing signatures. Slow processing is evident across latitudes, whereas rapid rates are restricted to lower latitudes. Both the mean rate and variability decline with latitude, suggesting temperature constraints toward the poles and greater roles for other environmental drivers (e.g., nutrient loading) toward the equator. These results and data set the stage for unprecedented “next-generation biomonitoring” by establishing baselines to help quantify environmental impacts to the functioning of ecosystems at a global scale. Y1 - 2019 U6 - https://doi.org/10.1126/sciadv.aav0486 SN - 2375-2548 VL - 5 IS - 1 PB - American Assoc. for the Advancement of Science CY - Washington ER - TY - JOUR A1 - Thomas, Jessica E. A1 - Carvalho, Gary R. A1 - Haile, James A1 - Rawlence, Nicolas J. A1 - Martin, Michael D. A1 - Ho, Simon Y. W. A1 - Sigfusson, Arnor P. A1 - Josefsson, Vigfus A. A1 - Frederiksen, Morten A1 - Linnebjerg, Jannie F. A1 - Castruita, Jose A. Samaniego A1 - Niemann, Jonas A1 - Sinding, Mikkel-Holger S. A1 - Sandoval-Velasco, Marcela A1 - Soares, Andre E. R. A1 - Lacy, Robert A1 - Barilaro, Christina A1 - Best, Juila A1 - Brandis, Dirk A1 - Cavallo, Chiara A1 - Elorza, Mikelo A1 - Garrett, Kimball L. A1 - Groot, Maaike A1 - Johansson, Friederike A1 - Lifjeld, Jan T. A1 - Nilson, Goran A1 - Serjeanston, Dale A1 - Sweet, Paul A1 - Fuller, Errol A1 - Hufthammer, Anne Karin A1 - Meldgaard, Morten A1 - Fjeldsa, Jon A1 - Shapiro, Beth A1 - Hofreiter, Michael A1 - Stewart, John R. A1 - Gilbert, M. Thomas P. A1 - Knapp, Michael T1 - Demographic reconstruction from ancient DNA supports rapid extinction of the great auk JF - eLife N2 - The great auk was once abundant and distributed across the North Atlantic. It is now extinct, having been heavily exploited for its eggs, meat, and feathers. We investigated the impact of human hunting on its demise by integrating genetic data, GPS-based ocean current data, and analyses of population viability. We sequenced complete mitochondrial genomes of 41 individuals from across the species' geographic range and reconstructed population structure and population dynamics throughout the Holocene. Taken together, our data do not provide any evidence that great auks were at risk of extinction prior to the onset of intensive human hunting in the early 16th century. In addition, our population viability analyses reveal that even if the great auk had not been under threat by environmental change, human hunting alone could have been sufficient to cause its extinction. Our results emphasise the vulnerability of even abundant and widespread species to intense and localised exploitation. Y1 - 2019 U6 - https://doi.org/10.7554/eLife.47509 SN - 2050-084X VL - 8 PB - eLife Sciences Publications CY - Cambridge ER - TY - THES A1 - Thirumalaikumar, Venkatesh P. T1 - Investigating drought and heat stress regulatory networks in Arabidopsis and tomato Y1 - 2019 ER - TY - JOUR A1 - Teckentrup, Lisa A1 - Kramer-Schadt, Stephanie A1 - Jeltsch, Florian T1 - The risk of ignoring fear: underestimating the effects of habitat loss and fragmentation on biodiversity JF - Landscape ecology KW - Predator-prey interactions KW - Fragmentation KW - Habitat loss KW - Landscape of fear KW - Biodiversity KW - Community Y1 - 2019 U6 - https://doi.org/10.1007/s10980-019-00922-8 SN - 0921-2973 SN - 1572-9761 VL - 34 IS - 12 SP - 2851 EP - 2868 PB - Springer CY - Dordrecht ER - TY - THES A1 - Teckentrup, Lisa T1 - Understanding predator-prey interactions T1 - Verstehen von Räuber-Beute-Interaktionen BT - the role of fear in structuring prey communities BT - die Rolle der Angst bei der Strukturierung von Beutetiergemeinschaften N2 - Predators can have numerical and behavioral effects on prey animals. While numerical effects are well explored, the impact of behavioral effects is unclear. Furthermore, behavioral effects are generally either analyzed with a focus on single individuals or with a focus on consequences for other trophic levels. Thereby, the impact of fear on the level of prey communities is overlooked, despite potential consequences for conservation and nature management. In order to improve our understanding of predator-prey interactions, an assessment of the consequences of fear in shaping prey community structures is crucial. In this thesis, I evaluated how fear alters prey space use, community structure and composition, focusing on terrestrial mammals. By integrating landscapes of fear in an existing individual-based and spatially-explicit model, I simulated community assembly of prey animals via individual home range formation. The model comprises multiple hierarchical levels from individual home range behavior to patterns of prey community structure and composition. The mechanistic approach of the model allowed for the identification of underlying mechanism driving prey community responses under fear. My results show that fear modified prey space use and community patterns. Under fear, prey animals shifted their home ranges towards safer areas of the landscape. Furthermore, fear decreased the total biomass and the diversity of the prey community and reinforced shifts in community composition towards smaller animals. These effects could be mediated by an increasing availability of refuges in the landscape. Under landscape changes, such as habitat loss and fragmentation, fear intensified negative effects on prey communities. Prey communities in risky environments were subject to a non-proportional diversity loss of up to 30% if fear was taken into account. Regarding habitat properties, I found that well-connected, large safe patches can reduce the negative consequences of habitat loss and fragmentation on prey communities. Including variation in risk perception between prey animals had consequences on prey space use. Animals with a high risk perception predominantly used safe areas of the landscape, while animals with a low risk perception preferred areas with a high food availability. On the community level, prey diversity was higher in heterogeneous landscapes of fear if individuals varied in their risk perception compared to scenarios in which all individuals had the same risk perception. Overall, my findings give a first, comprehensive assessment of the role of fear in shaping prey communities. The linkage between individual home range behavior and patterns at the community level allows for a mechanistic understanding of the underlying processes. My results underline the importance of the structure of the landscape of fear as a key driver of prey community responses, especially if the habitat is threatened by landscape changes. Furthermore, I show that individual landscapes of fear can improve our understanding of the consequences of trait variation on community structures. Regarding conservation and nature management, my results support calls for modern conservation approaches that go beyond single species and address the protection of biotic interactions. N2 - Raubtiere beeinflussen ihre Beute durch die Verringerung der Anzahl (numerische Effekte) und durch das Hervorrufen von Verhaltensänderungen (Verhaltenseffekte). Während die Auswirkungen von numerischen Effekten gut erforscht sind, sind die Auswirkungen von Verhaltenseffekten unklar. Außerdem werden bei Verhaltensänderungen selten die Auswirkungen auf die Beutetiergemeinschaft betrachtet, sondern nur die Effekte auf einzelne Individuen bzw. Arten oder auf andere Stufen der Nahrungskette. Eine Betrachtung auf der Stufe der Beutetiergemeinschaft ist jedoch sehr wichtig, da nur so ein umfassendes Verständnis von Räuber-Beute-Gemeinschaften möglich ist. In der vorliegenden Arbeit habe ich die Auswirkungen von Verhaltenseffekten auf die Raumnutzung und die Struktur von Beutetiergemeinschaften untersucht. Dazu habe ich ein räumliches Modell benutzt, welches die Bildung von Beutetiergemeinschaften über den individuellen Aufbau von Aktionsräumen der Beutetiere simuliert. Die Einrichtung von Aktionsräumen basiert dabei auf der Nahrungsverfügbarkeit in der Landschaft und auf dem vom Beutetier wahrgenommenen Risiko von einem Räuber gefressen zu werden. Die räumliche Verteilung des wahrgenommenen Risikos wird auch als Landschaft der Angst bezeichnet. Meine Ergebnisse zeigen, dass sich die Raumnutzung und die Struktur der Beutetiergemeinschaft durch Verhaltenseffekte verändern. Unter dem Einfluss von Angst haben die Beutetiere ihre Aktionsräume in sicherere Bereiche der Landschaft verlegt. Außerdem hat sich in risikoreichen Landschaften die Vielfalt der Beutetiere verringert und die Zusammensetzung zu Arten mit einem geringen Körpergewicht verschoben. Wenn die Beutetiergemeinschaft Landschaftsveränderungen wie z.B. dem Verlust oder der Zerschneidung von Lebensraum ausgesetzt war, haben sich die Auswirkungen von Verhaltenseffekten weiter verstärkt. Durch eine Erhöhung der Größe und Anzahl von Rückzugsräumen, die nicht von Räubern erreicht werden können, sowie deren Verbindung in der Landschaft, kann die Stärke dieser Effekte jedoch begrenzt werden. In einem weiteren Schritt habe ich die Auswirkungen von Unterschieden in der Risikowahrnehmung zwischen Individuen untersucht. Diese Unterschiede haben dazu geführt, dass Tiere mit einer hohen Risikowahrnehmung sich ihren Aktionsraum vornehmlich in sicheren Bereichen gesucht haben, während Tiere mit einer geringen Risikowahrnehmung Bereiche mit einer hohen Nahrungsverfügbarkeit genutzt haben. Dadurch konnten sich in Landschaften mit unterschiedlichen Risiken, vielfältigere Beutetiergemeinschaften etablieren, als in Landschaften mit gleichmäßigem Risiko. Insgesamt geben meine Ergebnisse einen guten Überblick über die Auswirkungen von Verhaltenseffekten auf Beutetiergemeinschaften. Die Verknüpfung von individuellem Verhalten mit Mustern auf der Gemeinschaftsebene erlaubt es die zugrundeliegenden Mechanismen zu identifizieren und zu verstehen. In Bezug auf den Naturschutz unterstützen meine Ergebnisse den Ruf nach modernen Schutzmaßnahmen, die über den Erhalt von einzelnen Arten hinausgehen und den Schutz von Beziehungen zwischen Arten einbeziehen. KW - ecology KW - landscape of fear KW - predator-prey KW - movement KW - biodiversity KW - Ökologie KW - Landschaft der Angst KW - Räuber-Beute KW - Bewegung KW - Biodiversität Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-431624 ER - TY - JOUR A1 - Teckentrup, Lisa T1 - Gefahr an jeder Ecke BT - wie die Landschaftsstruktur die Verteilung von Beutetieren beeinflusst JF - Vielfalt in der Uckermark : Forschungsprojekte 2015 - 2018 Y1 - 2019 SP - 54 EP - 55 PB - oerding print GmbH CY - Braunschweig ER - TY - THES A1 - Taube, Robert T1 - Characterisations of Fungal Communities in Temperate Lakes BT - with focus on diversity, abundance and methodological aspects of quantifying abundance Y1 - 2019 ER - TY - JOUR A1 - Tarazona, Natalia A. A1 - Machatschek, Rainhard Gabriel A1 - Schulz, Burkhard A1 - Auxiliadora Prieto Jiménez, M. A1 - Lendlein, Andreas T1 - Molecular Insights into the Physical Adsorption of Amphiphilic Protein PhaF onto Copolyester Surfaces JF - Biomacromolecules : an interdisciplinary journal focused at the interface of polymer science and the biological sciences N2 - Phasins are amphiphilic proteins located at the polymer-cytoplasm interface of bacterial polyhydroxyalkanoates (PHA). The immobilization of phasins on biomaterial surfaces is a promising way to enhance the hydrophilicity and supply cell- directing elements in bioinstructing processes. Optimizing the physical adsorption of phasins requires deep insights into molecular processes during polymer-protein interactions to preserve their structural conformation while optimizing surface coverage. Here, the assembly, organization, and stability of phasin PhaF from Pseudomonas putida at interfaces is disclosed. The Langmuir technique, combined with in situ microscopy and spectroscopic methods, revealed that PhaF forms stable and robust monolayers at different temperatures, with an almost flat orientation of its alpha-helix at the air-water interface. PhaF adsorption onto preformed monolayers of poly[(3-R-hydroxyoctanoate)-co-(3-R-hydroxyhexanoate)] (PHOHHx), yields stable mixed layers below pi = similar to 15.7 mN/m. Further insertion induces a molecular reorganization. PHOHHx with strong surface hydrophobicity is a more adequate substrate for PhaF adsorption than the less hydrophobic poly[(rac-lactide)-co-glycolide] (PLGA). The observed orientation of the main axis of the protein in relation to copolyester interfaces ensures the best exposure of the hydrophobic residues, providing a suitable coating strategy for polymer functionalization. Y1 - 2019 U6 - https://doi.org/10.1021/acs.biomac.9b00069 SN - 1525-7797 SN - 1526-4602 VL - 20 IS - 9 SP - 3242 EP - 3252 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Tarazona, Natalia A. A1 - Machatschek, Rainhard Gabriel A1 - Lendlein, Andreas T1 - Unraveling the interplay between abiotic hydrolytic degradation and crystallization of bacterial polyesters comprising short and medium side-chain-length Polyhydroxyalkanoates JF - Biomacromolecules : an interdisciplinary journal focused at the interface of polymer science and the biological sciences N2 - Polyhydroxyalkanoates (PHAs) have attracted attention as degradable (co)polyesters which can be produced by microorganisms with variations in the side chain. This structural variation influences not only the thermomechanical properties of the material but also its degradation behavior. Here, we used Langmuir monolayers at the air-water (A-W) interface as suitable models for evaluating the abiotic degradation of two PHAs with different side-chain lengths and crystallinity. By controlling the polymer state (semi crystalline, amorphous), the packing density, the pH, and the degradation mechanism, we could draw several significant conclusions. (i) The maximum degree of crystallinity for a PHA film to be efficiently degraded up to pH = 12.3 is 40%. (ii) PHA made of repeating units with shorter side-chain length are more easily hydrolyzed under alkaline conditions. The efficiency of alkaline hydrolysis decreased by about 65% when the polymer was 40% crystalline. (iii) In PHA films with a relatively high initial crystallinity, abiotic degradation initiated a chemicrystallization phenomenon, detected as an increase in the storage modulus (E'). This could translate into an increase in brittleness and reduction in the material degradability. Finally, we demonstrate the stability of the measurement system for long-term experiments, which allows degradation conditions for polymers that could closely simulate real-time degradation. Y1 - 2019 U6 - https://doi.org/10.1021/acs.biomac.9b01458 SN - 1525-7797 SN - 1526-4602 VL - 21 IS - 2 SP - 761 EP - 771 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Tanner, Norman A1 - Lichtenberg-Kraag, Birgit T1 - Identification and Quantification of Single and Multi-Adulteration of Beeswax by FTIR-ATR Spectroscopy JF - European journal of lipid science and technology N2 - Marketing of adulterated beeswax foundation has recently become a major economic problem for beekeepers. Paraffin contamination leads to collapse of combs, and stearic acid has a negative influence on the development of bee brood. The quality of beeswax for beekeeping has not been standardized in EU regulations. Recently, it was shown that attenuated total reflectance Fourier-transform infrared spectroscopy (FTIR-ATR) can be used to determine beeswax adulteration. Differences in the IR spectra of authentic beeswax can be identified and calculated through comparison with authentic beeswax. In this study, the method is further validated by employing a high number of samples of authentic beeswax from different origins. Low quantification and detection limits are achieved for paraffin, stearic acid, tallow, carnauba wax, and candelilla wax. Furthermore, the FTIR-ATR analytical conditions are verified by analyzing 358 samples of commercial and beekeeper-produced beeswax foundations. Multi-adulterated samples with as many as five different additives in beeswax mixtures are identified with the same accuracy as single substances. Additionally, the spectra of a further 14 different natural and synthetic waxes and hardened fats are analyzed and are compared with beeswax. Finally, a spectral library is established that can be used for further studies. Practical Applications: FTIR-ATR is a fast and cost-efficient tool in beeswax analysis for accurately monitoring a high sample volume. Analysis of 358 beeswax foundations showed an adulteration of 21.8% of the samples with paraffin, stearic acid, tallow, and combinations. Based on the results of this study, it is possible to detect beeswax adulteration of less than 3% of these adulterants and their combinations by FTIR-ATR spectroscopy. This method can be used for monitoring beeswax foundations to identify adulterated materials, exclude these materials from the recycling process, and produce high-quality beeswax, which is essential for bee health. KW - beeswax KW - beeswax substitutes KW - candelilla wax KW - carnauba wax KW - FTIR-ATR KW - multi-adulteration KW - paraffin KW - stearic acid KW - tallow Y1 - 2019 U6 - https://doi.org/10.1002/ejlt.201900245 SN - 1438-7697 SN - 1438-9312 VL - 121 IS - 12 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Tang, Kam W. A1 - Backhaus, Liv A1 - Riemann, Lasse A1 - Koski, Marja A1 - Grossart, Hans-Peter A1 - Munk, Peter A1 - Nielsen, Torkel Gissel T1 - Copepod carcasses in the subtropical convergence zone of the Sargasso Sea BT - implications for microbial community composition, system respiration and carbon flux JF - Journal of plankton research N2 - The oligotrophic subtropical gyre covers a vast area of the Atlantic Ocean. Decades of time-series monitoring have generated detailed temporal information about zooplankton species and abundances at fixed locations within the gyre, but their live/dead status is often omitted, especially in the dynamic subtropical convergence zone (STCZ) where the water column stratification pattern can change considerably across the front as warm and cold water masses converge. We conducted a detailed survey in the North Atlantic STCZ and showed that over 85% of the copepods were typically concentrated in the upper 200 m. Copepod carcasses were present in all samples and their proportional numerical abundances increased with depth, reaching up to 91% at 300-400 m. Overall, 14-19% of the copepods within the upper 200 m were carcasses. Shipboard experiments showed that during carcass decomposition, microbial respiration increased, and the bacterial community associated with the carcasses diverged from that in the ambient water. Combining field and experimental data, we estimated that decomposing copepod carcasses constitute a negligible oxygen sink in the STCZ, but sinking carcasses may represent an overlooked portion of the passive carbon sinking flux and should be incorporated in future studies of carbon flux in this area. KW - Sargasso Sea KW - subtropical convergence zone KW - zooplankton KW - carcasses KW - carbon sinking flux Y1 - 2019 U6 - https://doi.org/10.1093/plankt/fbz038 SN - 0142-7873 SN - 1464-3774 VL - 41 IS - 4 SP - 549 EP - 560 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Tang, Jing A1 - Werchmeister, Rebecka Maria Larsen A1 - Preda, Loredana A1 - Huang, Wei A1 - Zheng, Zhiyong A1 - Leimkühler, Silke A1 - Wollenberger, Ulla A1 - Xiao, Xinxin A1 - Engelbrekt, Christian A1 - Ulstrup, Jens A1 - Zhang, Jingdong T1 - Three-dimensional sulfite oxidase bioanodes based on graphene functionalized carbon paper for sulfite/O-2 biofuel cells JF - ACS catalysis N2 - We have developed a three-dimensional (3D) graphene electrode suitable for the immobilization of human sulfite oxidase (hSO), which catalyzes the electrochemical oxidation of sulfite via direct electron transfer (DET). The electrode is fabricated by drop-casting graphene-polyethylenimine (G-P) composites on carbon papers (CPs) precoated with graphene oxide (GO). The negatively charged hSO can be adsorbed electrostatically on the positively charged matrix (G-P) on CP electrodes coated with GO (CPG), with a proper orientation for accelerated DET. Notably, further electrochemical reduction of G-P on CPG electrodes leads to a 9-fold increase of the saturation catalytic current density (j(m)) for sulfite oxidation reaching 24.4 +/- 0.3 mu A to cm(-2), the highest value among reported DET-based hSO bioelectrodes. The increased electron transfer rate plays a dominating role in the enhancement of direct enzymatic current because of the improved electric contact of hSO with the electrode, The optimized hSO bioelectrode shows a significant catalytic rate (k(cat): 25.6 +/- 0.3 s(-1)) and efficiency (k(cat)/K-m: 0.231 +/- 0.003 s(-1) mu M-1) compared to the reported hSO bioelectrodes. The assembly of the hSO bioanode and a commercial platinum biocathode allows the construction of sulfite/O-2 enzymatic biofuel cells (EBFCs) with flowing fuels. The optimized EBFC displays an open-circuit voltage (OCV) of 0.64 +/- 0.01 V and a maximum power density of 61 +/- 6 mu W cm(-2) (122 +/- 12 mW m(-3)) at 30 degrees C, which exceeds the best reported value by more than 6 times. KW - enzymatic biofuel cell KW - reduced graphene oxide KW - sulfite oxidase KW - carbon paper KW - direct electron transfer Y1 - 2019 U6 - https://doi.org/10.1021/acscatal.9b01715 SN - 2155-5435 VL - 9 IS - 7 SP - 6543 EP - 6554 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Tang, Alan T. A1 - Sullivan, Katie Rose A1 - Hong, Courtney C. A1 - Goddard, Lauren M. A1 - Mahadevan, Aparna A1 - Ren, Aileen A1 - Pardo, Heidy A1 - Peiper, Amy A1 - Griffin, Erin A1 - Tanes, Ceylan A1 - Mattei, Lisa M. A1 - Yang, Jisheng A1 - Li, Li A1 - Mericko-Ishizuka, Patricia A1 - Shen, Le A1 - Hobson, Nicholas A1 - Girard, Romuald A1 - Lightle, Rhonda A1 - Moore, Thomas A1 - Shenkar, Robert A1 - Polster, Sean P. A1 - Roedel, Claudia Jasmin A1 - Li, Ning A1 - Zhu, Qin A1 - Whitehead, Kevin J. A1 - Zheng, Xiangjian A1 - Akers, Amy A1 - Morrison, Leslie A1 - Kim, Helen A1 - Bittinger, Kyle A1 - Lengner, Christopher J. A1 - Schwaninger, Markus A1 - Velcich, Anna A1 - Augenlicht, Leonard A1 - Abdelilah-Seyfried, Salim A1 - Min, Wang A1 - Marchuk, Douglas A. A1 - Awad, Issam A. A1 - Kahn, Mark L. T1 - Distinct cellular roles for PDCD10 define a gut-brain axis in cerebral cavernous malformation JF - Science Translational Medicine N2 - Cerebral cavernous malformation (CCM) is a genetic, cerebrovascular disease. Familial CCM is caused by genetic mutations in KRIT1, CCM2, or PDCD10. Disease onset is earlier and more severe in individuals with PDCD10 mutations. Recent studies have shown that lesions arise from excess mitogen-activated protein kinase kinase kinase 3 (MEKK3) signaling downstream of Toll-like receptor 4 (TLR4) stimulation by lipopolysaccharide derived from the gut microbiome. These findings suggest a gut-brain CCM disease axis but fail to define it or explain the poor prognosis of patients with PDCD10 mutations. Here, we demonstrate that the gut barrier is a primary determinant of CCM disease course, independent of microbiome configuration, that explains the increased severity of CCM disease associated with PDCD10 deficiency. Chemical disruption of the gut barrier with dextran sulfate sodium augments CCM formation in a mouse model, as does genetic loss of Pdcd10, but not Krit1, in gut epithelial cells. Loss of gut epithelial Pdcd10 results in disruption of the colonic mucosal barrier. Accordingly, loss of Mucin-2 or exposure to dietary emulsifiers that reduce the mucus barrier increases CCM burden analogous to loss of Pdcd10 in the gut epithelium. Last, we show that treatment with dexamethasone potently inhibits CCM formation in mice because of the combined effect of action at both brain endothelial cells and gut epithelial cells. These studies define a gut-brain disease axis in an experimental model of CCM in which a single gene is required for two critical components: gut epithelial function and brain endothelial signaling. Y1 - 2019 U6 - https://doi.org/10.1126/scitranslmed.aaw3521 SN - 1946-6234 SN - 1946-6242 VL - 11 IS - 520 PB - American Assoc. for the Advancement of Science CY - Washington ER - TY - JOUR A1 - Tanabe, Tomohisa Sebastian A1 - Leimkühler, Silke A1 - Dahl, Christiane ED - Poole, RK T1 - The functional diversity of the prokaryotic sulfur carrier protein TusA JF - Advances in microbial physiology N2 - Persulfide groups participate in a wide array of biochemical pathways and are chemically very versatile. The TusA protein has been identified as a central element supplying and transferring sulfur as persulfide to a number of important biosynthetic pathways, like molybdenum cofactor biosynthesis or thiomodifications in nucleosides of tRNAs. In recent years, it has furthermore become obvious that this protein is indispensable for the oxidation of sulfur compounds in the cytoplasm. Phylogenetic analyses revealed that different TusA protein variants exists in certain organisms, that have evolved to pursue specific roles in cellular pathways. The specific TusA-like proteins thereby cannot replace each other in their specific roles and are rather specific to one sulfur transfer pathway or shared between two pathways. While certain bacteria like Escherichia coli contain several copies of TusA-like proteins, in other bacteria like Allochromatium vinosum a single copy of TusA is present with an essential role for this organism. Here, we give an overview on the multiple roles of the various TusA-like proteins in sulfur transfer pathways in different organisms to shed light on the remaining mysteries of this versatile protein. Y1 - 2019 SN - 978-0-12-817715-0 SN - 978-0-12-817714-3 U6 - https://doi.org/10.1016/bs.ampbs.2019.07.004 SN - 0065-2911 VL - 75 SP - 233 EP - 277 PB - Elsevier Acad. Press CY - Amsterdam ER - TY - JOUR A1 - Tabares Jimenez, Ximena del Carmen A1 - Zimmermann, Heike Hildegard A1 - Dietze, Elisabeth A1 - Ratzmann, Gregor A1 - Belz, Lukas A1 - Vieth-Hillebrand, Andrea A1 - Dupont, Lydie A1 - Wilkes, Heinz A1 - Mapani, Benjamin A1 - Herzschuh, Ulrike T1 - Vegetation state changes in the course of shrub encroachment in an African savanna since about 1850 CE and their potential drivers JF - Ecology and evolution N2 - Shrub encroachment has far-reaching ecological and economic consequences in many ecosystems worldwide. Yet, compositional changes associated with shrub encroachment are often overlooked despite having important effects on ecosystem functioning. We document the compositional change and potential drivers for a northern Namibian Combretum woodland transitioning into a Terminalia shrubland. We use a multiproxy record (pollen, sedimentary ancient DNA, biomarkers, compound-specific carbon (delta C-13) and deuterium (delta D) isotopes, bulk carbon isotopes (delta(13)Corg), grain size, geochemical properties) from Lake Otjikoto at high taxonomical and temporal resolution. We provide evidence that state changes in semiarid environments may occur on a scale of one century and that transitions between stable states can span around 80 years and are characterized by a unique vegetation composition. We demonstrate that the current grass/woody ratio is exceptional for the last 170 years, as supported by n-alkane distributions and the delta C-13 and delta(13)Corg records. Comparing vegetation records to environmental proxy data and census data, we infer a complex network of global and local drivers of vegetation change. While our delta D record suggests physiological adaptations of woody species to higher atmospheric pCO(2) concentration and drought, our vegetation records reflect the impact of broad-scale logging for the mining industry, and the macrocharcoal record suggests a decrease in fire activity associated with the intensification of farming. Impact of selective grazing is reflected by changes in abundance and taxonomical composition of grasses and by an increase of nonpalatable and trampling-resistant taxa. In addition, grain-size and spore records suggest changes in the erodibility of soils because of reduced grass cover. Synthesis. We conclude that transitions to an encroached savanna state are supported by gradual environmental changes induced by management strategies, which affected the resilience of savanna ecosystems. In addition, feedback mechanisms that reflect the interplay between management legacies and climate change maintain the encroached state. KW - climate change KW - fossil pollen KW - land-use change KW - savanna ecology KW - sedimentary ancient DNA KW - state and transition KW - tree-grass interactions Y1 - 2019 U6 - https://doi.org/10.1002/ece3.5955 SN - 2045-7758 VL - 10 IS - 2 SP - 962 EP - 979 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Steger, Kristin A1 - Kim, Amy Taeyen A1 - Ganzert, Lars A1 - Grossart, Hans-Peter A1 - Smart, David R. T1 - Floodplain soil and its bacterial composition are strongly affected by depth JF - FEMS microbiology ecology N2 - We studied bacterial abundance and community structure of five soil cores using high-throughput sequencing of the 16S rRNA gene. Shifts in the soil bacterial composition were more pronounced within a vertical profile than across the landscape. Soil organic carbon (SOC) and nitrogen (N) concentrations decreased exponentially with soil depth and revealed a buried carbon-rich horizon between 0.8 and 1.3 m across all soil cores. This buried horizon was phylogenetically similar to its surrounding subsoils supporting the idea that the type of carbon, not necessarily the amount of carbon was driving the apparent similarities. In contrast to other studies, Nitrospirae was one of our major phyla with relatively high abundances throughout the soil profile except for the surface soil. Although depth is the major driver shaping soil bacterial community structure, positive correlations with SOC and N concentrations, however, were revealed with the bacterial abundance of Acidobacteria, one of the major, and Gemmatimonadetes, one of the minor phyla in our study. Our study showed that bacterial diversity in soils below 2.0 m can be still as high if not higher than in the above laying subsurface soil suggesting that various bacteria throughout the soil profile influence major biogeochemical processes in floodplain soils. KW - 16S rRNA gene sequencing KW - alluvial soil KW - buried horizon KW - Nitrospirae KW - soil bacterial diversity KW - SOC Y1 - 2019 U6 - https://doi.org/10.1093/femsec/fiz014 SN - 0168-6496 SN - 1574-6941 VL - 95 IS - 3 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Staszek, Pawel A1 - Krasuska, Urszula A1 - Otulak-Koziel, Katarzyna A1 - Fettke, Jörg A1 - Gniazdowska, Agnieszka T1 - Canavanine-Induced Decrease in Nitric Oxide Synthesis Alters Activity of Antioxidant System but Does Not Impact S-Nitrosoglutathione Catabolism in Tomato Roots JF - Frontiers in plant science N2 - Canavanine (CAN) is a nonproteinogenic amino acid synthesized in legumes. In mammalians, as arginine analogue, it is an inhibitor of nitric oxide synthase (NOS) activity. The aim of this study was to investigate the impact of CAN-induced nitric oxide level limitation on the antioxidant system and S-nitrosoglutathione (GSNO) metabolism in roots of tomato seedlings. Treatment with CAN (10 or 50 mu M) for 24-72 h led to restriction in root growth. Arginine-dependent NOS-like activity was almost completely inhibited, demonstrating direct effect of CAN action. CAN increased total antioxidant capacity and the level of sulphydryl groups. Catalase (CAT) and superoxide dismutase (SOD) activity decreased in CAN exposed roots. CAN supplementation resulted in the decrease of transcript levels of genes coding CAT (with the exception of CAT1). Genes coding SOD (except MnSOD and CuSOD) were upregulated by CAN short treatment; prolonged exposition to 50-mu M CAN resulted in downregulation of FeSOD, CuSOD, and SODP-2. Activity of glutathione reductase dropped down after short-term (10-mu M CAN) supplementation, while glutathione peroxidase activity was not affected. Transcript levels of glutathione reductase genes declined in response to CAN. Genes coding glutathione peroxidase were upregulated by 50-mu M CAN, while 10-mu M CAN downregulated GSHPx1. Inhibition of NOS-like activity by CAN resulted in lower GSNO accumulation in root tips. Activity of GSNO reductase was decreased by short-term supplementation with CAN. In contrast, GSNO reductase protein abundance was higher, while transcript levels were slightly altered in roots exposed to CAN. This is the first report on identification of differentially nitrated proteins in response to supplementation with nonproteinogenic amino acid. Among nitrated proteins differentially modified by CAN, seed storage proteins (after short-term CAN treatment) and components of the cellular redox system (after prolonged CAN supplementation) were identified. The findings demonstrate that due to inhibition of NOS-like activity, CAN leads to modification in antioxidant system. Limitation in GSNO level is due to lower nitric oxide formation, while GSNO catabolism is less affected. We demonstrated that monodehydroascorbate reductase, activity of which is inhibited in roots of CAN-treated plants, is the protein preferentially modified by tyrosine nitration. KW - canavanine KW - cellular antioxidant system KW - GSNOR-GSNO reductase KW - nitrated proteins KW - nitric oxide-NO KW - nonproteinogenic amino acid KW - NOS-like activity KW - reactive nitrogen species (RNS) Y1 - 2019 U6 - https://doi.org/10.3389/fpls.2019.01077 SN - 1664-462X VL - 10 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Sroka, Pavel A1 - Godunko, Roman J. A1 - Rutschmann, Sereina A1 - Angeli, Kamila B. A1 - Salles, Frederico F. A1 - Gattolliat, Jean-Luc T1 - A new species of Bungona in Turkey (Ephemeroptera, Baetidae) BT - an unexpected biogeographic pattern within a pantropical complex of mayflies JF - Zoosytematics and evolution N2 - By using an integrative approach, we describe a new species of mayfly, Bungona (Chopralla) pontica sp. n., from Turkey. The discovery of a representative of the tropical mayfly genus Bungona in the Middle East is rather unexpected. The new species shows all the main morphological characters of the subgenus Chopralla, which has its closest related species occurring in southeastern Asia. Barcoding clearly indicated that the new species represents an independent lineage isolated for a very long time from other members of the complex. The claw is equipped with two rows of three or four flattened denticles. This condition is a unique feature of Bungona (Chopralla) pontica sp. n. among West Palaearctic mayfly species. Within the subgenus Chopralla, the species can be identified by the presence of a simple, not bifid right prostheca (also present only in Bungona (Chopralla) liebenauae (Soldan, Braasch & Muu, 1987)), the shape of the labial palp, and the absence of protuberances on pronotum. KW - Biogeography KW - Cloeodes complex KW - Chopralla KW - integrative taxonomy KW - Middle East KW - new species Y1 - 2019 U6 - https://doi.org/10.3897/zse.95.29487 SN - 1860-0743 VL - 95 IS - 1 SP - 1 EP - 13 PB - Pensoft Publ. CY - Sofia ER - TY - JOUR A1 - Sperber, Hannah Sabeth A1 - Welke, Robert-William A1 - Petazzi, Roberto Arturo A1 - Bergmann, Ronny A1 - Schade, Matthias A1 - Shai, Yechiel A1 - Chiantia, Salvatore A1 - Herrmann, Andreas A1 - Schwarzer, Roland T1 - Self-association and subcellular localization of Puumala hantavirus envelope proteins JF - Scientific reports N2 - Hantavirus assembly and budding are governed by the surface glycoproteins Gn and Gc. In this study, we investigated the glycoproteins of Puumala, the most abundant Hantavirus species in Europe, using fluorescently labeled wild-type constructs and cytoplasmic tail (CT) mutants. We analyzed their intracellular distribution, co-localization and oligomerization, applying comprehensive live, single-cell fluorescence techniques, including confocal microscopy, imaging flow cytometry, anisotropy imaging and Number&Brightness analysis. We demonstrate that Gc is significantly enriched in the Golgi apparatus in absence of other viral components, while Gn is mainly restricted to the endoplasmic reticulum (ER). Importantly, upon co-expression both glycoproteins were found in the Golgi apparatus. Furthermore, we show that an intact CT of Gc is necessary for efficient Golgi localization, while the CT of Gn influences protein stability. Finally, we found that Gn assembles into higher-order homo-oligomers, mainly dimers and tetramers, in the ER while Gc was present as mixture of monomers and dimers within the Golgi apparatus. Our findings suggest that PUUV Gc is the driving factor of the targeting of Gc and Gn to the Golgi region, while Gn possesses a significantly stronger self-association potential. Y1 - 2019 U6 - https://doi.org/10.1038/s41598-018-36879-y SN - 2045-2322 VL - 9 PB - Nature Publ. Group CY - London ER - TY - GEN A1 - Sowemimo, Oluwakemi T. A1 - Knox-Brown, Patrick A1 - Borcherds, Wade A1 - Rindfleisch, Tobias A1 - Thalhammer, Anja A1 - Daughdrill, Gary W. T1 - Conserved glycines control disorder and function in the cold-regulated protein, COR15A T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Cold-regulated (COR) 15A is an intrinsically disordered protein (IDP) from Arabidopsis thaliana important for freezing tolerance. During freezing-induced cellular dehydration, COR15A transitions from a disordered to mostly alpha-helical structure. We tested whether mutations that increase the helicity of COR15A also increase its protective function. Conserved glycine residues were identified and mutated to alanine. Nuclear magnetic resonance (NMR) spectroscopy was used to identify residue-specific changes in helicity for wildtype (WT) COR15A and the mutants. Circular dichroism (CD) spectroscopy was used to monitor the coil-helix transition in response to increasing concentrations of trifluoroethanol (TFE) and ethylene glycol. The impact of the COR15A mutants on the stability of model membranes during a freeze-thaw cycle was investigated by fluorescence spectroscopy. The results of these experiments showed the mutants had a higher content of alpha-helical structure and the increased alpha-helicity improved membrane stabilization during freezing. Comparison of the TFE- and ethylene glycol-induced coil-helix transitions support our conclusion that increasing the transient helicity of COR15A in aqueous solution increases its ability to stabilize membranes during freezing. Altogether, our results suggest the conserved glycine residues are important for maintaining the disordered structure of COR15A but are also compatible with the formation of alpha-helical structure during freezing induced dehydration. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1089 KW - COR15A KW - late embryogenesis abundant KW - intrinsically disordered proteins KW - trifluoroethanol KW - nuclear magnetic resonance Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-472217 SN - 1866-8372 IS - 1089 ER - TY - JOUR A1 - Sowemimo, Oluwakemi T. A1 - Knox-Brown, Patrick A1 - Borcherds, Wade A1 - Rindfleisch, Tobias A1 - Thalhammer, Anja A1 - Daughdrill, Gary W. T1 - Conserved Glycines Control Disorder and Function in the Cold-Regulated Protein, COR15A JF - Biomolecules N2 - Cold-regulated (COR) 15A is an intrinsically disordered protein (IDP) from Arabidopsis thaliana important for freezing tolerance. During freezing-induced cellular dehydration, COR15A transitions from a disordered to mostly alpha-helical structure. We tested whether mutations that increase the helicity of COR15A also increase its protective function. Conserved glycine residues were identified and mutated to alanine. Nuclear magnetic resonance (NMR) spectroscopy was used to identify residue-specific changes in helicity for wildtype (WT) COR15A and the mutants. Circular dichroism (CD) spectroscopy was used to monitor the coil-helix transition in response to increasing concentrations of trifluoroethanol (TFE) and ethylene glycol. The impact of the COR15A mutants on the stability of model membranes during a freeze-thaw cycle was investigated by fluorescence spectroscopy. The results of these experiments showed the mutants had a higher content of alpha-helical structure and the increased alpha-helicity improved membrane stabilization during freezing. Comparison of the TFE- and ethylene glycol-induced coil-helix transitions support our conclusion that increasing the transient helicity of COR15A in aqueous solution increases its ability to stabilize membranes during freezing. Altogether, our results suggest the conserved glycine residues are important for maintaining the disordered structure of COR15A but are also compatible with the formation of alpha-helical structure during freezing induced dehydration. KW - COR15A KW - Late embryogenesis abundant KW - intrinsically disordered proteins KW - Trifluoroethanol KW - Nuclear magnetic resonance Y1 - 2019 U6 - https://doi.org/10.3390/biom9030084 SN - 2218-273X VL - 9 IS - 3 PB - MDPI CY - Basel ER - TY - GEN A1 - Sowemimo, Oluwakemi A1 - Borcherds, Wade A1 - Knox-Brown, Patrick A1 - Rindfleisch, Tobias A1 - Thalhammer, Anja A1 - Daughdrill, Gary T1 - Evolution of Transient Helicity and Disorder in Late Embryogenesis Abundant Protein COR15A T2 - Biophysical journal N2 - Cold regulated protein 15A (COR15A) is a nuclear encoded, intrinsically disordered protein that is found in Arabidopsis thaliana. It belongs to the Late Embryogenesis Abundant (LEA) family of proteins and is responsible for increased freezing tolerance in plants. COR15A is intrinsically disordered in dilute solutions and adopts a helical structure upon dehydration or in the presence of co-solutes such as TFE and ethylene glycol. This helical structure is thought to be important for protecting plants from dehydration induced by freezing. Multiple protein sequence alignments revealed the presence of several conserved glycine residues that we hypothesize keeps COR15A from becoming helical in dilute solutions. Using AGADIR, the change in helical content of COR15A when these conserved glycine residues were mutated to alanine residues was predicted. Based on the predictions, glycine to alanine mutants were made at position 68, and 54,68,81, and 84. Labeled samples of wildtype COR15A and mutant proteins were purified and NMR experiments were performed to examine any structural changes induced by the mutations. To test the effects of dehydration on the structure of COR15A, trifluoroethanol, an alcohol based co solvent that is proposed to induce/stabilize helical structure in peptides was added to the NMR samples, and the results of the experiment showed an increase in helical content, compared to the samples without TFE. To test the functional differences between wild type and the mutants, liposome leakage assays were performed. The results from these assays suggest the more helical mutants may augment membrane stability. Y1 - 2019 U6 - https://doi.org/10.1016/j.bpj.2018.11.2553 SN - 0006-3495 SN - 1542-0086 VL - 116 IS - 3 SP - 473A EP - 473A PB - Cell Press CY - Cambridge ER - TY - JOUR A1 - Song, Yu A1 - Li, Gang A1 - Nowak, Jacqueline A1 - Zhang, Xiaoqing A1 - Xu, Dongbei A1 - Yang, Xiujuan A1 - Huang, Guoqiang A1 - Liang, Wanqi A1 - Yang, Litao A1 - Wang, Canhua A1 - Bulone, Vincent A1 - Nikoloski, Zoran A1 - Hu, Jianping A1 - Persson, Staffan A1 - Zhang, Dabing T1 - The Rice Actin-Binding Protein RMD Regulates Light-Dependent Shoot Gravitropism JF - Plant physiology : an international journal devoted to physiology, biochemistry, cellular and molecular biology, biophysics and environmental biology of plants N2 - Light and gravity are two key determinants in orientating plant stems for proper growth and development. The organization and dynamics of the actin cytoskeleton are essential for cell biology and critically regulated by actin-binding proteins. However, the role of actin cytoskeleton in shoot negative gravitropism remains controversial. In this work, we report that the actin-binding protein Rice Morphology Determinant (RMD) promotes reorganization of the actin cytoskeleton in rice (Oryza sativa) shoots. The changes in actin organization are associated with the ability of the rice shoots to respond to negative gravitropism. Here, light-grown rmd mutant shoots exhibited agravitropic phenotypes. By contrast, etiolated rmd shoots displayed normal negative shoot gravitropism. Furthermore, we show that RMD maintains an actin configuration that promotes statolith mobility in gravisensing endodermal cells, and for proper auxin distribution in light-grown, but not dark-grown, shoots. RMD gene expression is diurnally controlled and directly repressed by the phytochrome-interacting factor-like protein OsPIL16. Consequently, overexpression of OsPIL16 led to gravisensing and actin patterning defects that phenocopied the rmd mutant. Our findings outline a mechanism that links light signaling and gravity perception for straight shoot growth in rice. Y1 - 2019 U6 - https://doi.org/10.1104/pp.19.00497 SN - 0032-0889 SN - 1532-2548 VL - 181 IS - 2 SP - 630 EP - 644 PB - American Society of Plant Physiologists CY - Rockville ER - TY - JOUR A1 - Smith, Sarah R. A1 - Dupont, Chris L. A1 - McCarthy, James K. A1 - Broddrick, Jared T. A1 - Obornik, Miroslav A1 - Horak, Ales A1 - Füssy, Zoltán A1 - Cihlar, Jaromir A1 - Kleessen, Sabrina A1 - Zheng, Hong A1 - McCrow, John P. A1 - Hixson, Kim K. A1 - Araujo, Wagner L. A1 - Nunes-Nesi, Adriano A1 - Fernie, Alisdair R. A1 - Nikoloski, Zoran A1 - Palsson, Bernhard O. A1 - Allen, Andrew E. T1 - Evolution and regulation of nitrogen flux through compartmentalized metabolic networks in a marine diatom JF - Nature Communications N2 - Diatoms outcompete other phytoplankton for nitrate, yet little is known about the mechanisms underpinning this ability. Genomes and genome-enabled studies have shown that diatoms possess unique features of nitrogen metabolism however, the implications for nutrient utilization and growth are poorly understood. Using a combination of transcriptomics, proteomics, metabolomics, fluxomics, and flux balance analysis to examine short-term shifts in nitrogen utilization in the model pennate diatom in Phaeodactylum tricornutum, we obtained a systems-level understanding of assimilation and intracellular distribution of nitrogen. Chloroplasts and mitochondria are energetically integrated at the critical intersection of carbon and nitrogen metabolism in diatoms. Pathways involved in this integration are organelle-localized GS-GOGAT cycles, aspartate and alanine systems for amino moiety exchange, and a split-organelle arginine biosynthesis pathway that clarifies the role of the diatom urea cycle. This unique configuration allows diatoms to efficiently adjust to changing nitrogen status, conferring an ecological advantage over other phytoplankton taxa. KW - Biochemistry KW - Computational biology and bioinformatics KW - Evolution KW - Microbiology KW - Molecular biology Y1 - 2019 U6 - https://doi.org/10.1038/s41467-019-12407-y SN - 2041-1723 VL - 10 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Signore, Anthony V. A1 - Paijmans, Johanna L. A. A1 - Hofreiter, Michael A1 - Fago, Angela A1 - Weber, Roy E. A1 - Springer, Mark S. A1 - Campbell, Kevin L. T1 - Emergence of a chimeric globin pseudogene and increased Hemoglobin Oxygen Affinity Underlie the evolution of aquatic specializations in Sirenia JF - Molecular biology and evolution N2 - As limits on O2 availability during submergence impose severe constraints on aerobic respiration, the oxygen binding globin proteins of marine mammals are expected to have evolved under strong evolutionary pressures during their land-to-sea transition. Here, we address this question for the order Sirenia by retrieving, annotating, and performing detailed selection analyses on the globin repertoire of the extinct Steller’s sea cow (Hydrodamalis gigas), dugong (Dugong dugon), and Florida manatee (Trichechus manatus latirostris) in relation to their closest living terrestrial relatives (elephants and hyraxes). These analyses indicate most loci experienced elevated nucleotide substitution rates during their transition to a fully aquatic lifestyle. While most of these genes evolved under neutrality or strong purifying selection, the rate of nonsynonymous/synonymous replacements increased in two genes (Hbz-T1 and Hba-T1) that encode the α-type chains of hemoglobin (Hb) during each stage of life. Notably, the relaxed evolution of Hba-T1 is temporally coupled with the emergence of a chimeric pseudogene (Hba-T2/Hbq-ps) that contributed to the tandemly linked Hba-T1 of stem sirenians via interparalog gene conversion. Functional tests on recombinant Hb proteins from extant and ancestral sirenians further revealed that the molecular remodeling of Hba-T1 coincided with increased Hb–O2 affinity in early sirenians. Available evidence suggests that this trait evolved to maximize O2 extraction from finite lung stores and suppress tissue O2 offloading, thereby facilitating the low metabolic intensities of extant sirenians. In contrast, the derived reduction in Hb–O2 affinity in (sub)Arctic Steller’s sea cows is consistent with fueling increased thermogenesis by these once colossal marine herbivores. KW - ancient DNA KW - aquatic adaptation KW - gene conversion KW - hemoglobin KW - oxygen affinity KW - molecular evolution KW - myoglobin KW - neuroglobin KW - cytoglobin KW - pseudogene Y1 - 2019 U6 - https://doi.org/10.1093/molbev/msz044 SN - 0737-4038 SN - 1537-1719 VL - 36 IS - 6 SP - 1134 EP - 1147 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Sheng, Gui-Lian A1 - Basler, Nikolas A1 - Ji, Xue-Ping A1 - Paijmans, Johanna L. A. A1 - Alberti, Federica A1 - Preick, Michaela A1 - Hartmann, Stefanie A1 - Westbury, Michael V. A1 - Yuan, Jun-Xia A1 - Jablonski, Nina G. A1 - Xenikoudakis, Georgios A1 - Hou, Xin-Dong A1 - Xiao, Bo A1 - Liu, Jian-Hui A1 - Hofreiter, Michael A1 - Lai, Xu-Long A1 - Barlow, Axel T1 - Paleogenome reveals genetic contribution of extinct giant panda to extant populations JF - Current biology N2 - Historically, the giant panda was widely distributed from northern China to southwestern Asia [1]. As a result of range contraction and fragmentation, extant individuals are currently restricted to fragmented mountain ranges on the eastern margin of the Qinghai-Tibet plateau, where they are distributed among three major population clusters [2]. However, little is known about the genetic consequences of this dramatic range contraction. For example, were regions where giant pandas previously existed occupied by ancestors of present-day populations, or were these regions occupied by genetically distinct populations that are now extinct? If so, is there any contribution of these extinct populations to the genomes of giant pandas living today? To investigate these questions, we sequenced the nuclear genome of an similar to 5,000-year-old giant panda from Jiangdongshan, Teng-chong County in Yunnan Province, China. We find that this individual represents a genetically distinct population that diverged prior to the diversification of modern giant panda populations. We find evidence of differential admixture with this ancient population among modern individuals originating from different populations as well as within the same population. We also find evidence for directional gene flow, which transferred alleles from the ancient population into the modern giant panda lineages. A variable proportion of the genomes of extant individuals is therefore likely derived from the ancient population represented by our sequenced individual. Although extant giant panda populations retain reasonable genetic diversity, our results suggest that this represents only part of the genetic diversity this species harbored prior to its recent range contractions. Y1 - 2019 U6 - https://doi.org/10.1016/j.cub.2019.04.021 SN - 0960-9822 SN - 1879-0445 VL - 29 IS - 10 SP - 1695 EP - 1700 PB - Cell Press CY - Cambridge ER - TY - JOUR A1 - Seitz, Aaron P. A1 - Schumacher, Fabian A1 - Baker, Jennifer A1 - Soddemann, Matthias A1 - Wilker, Barbara A1 - Caldwell, Charles C. A1 - Gobble, Ryan M. A1 - Kamler, Markus A1 - Becker, Katrin Anne A1 - Beck, Sascha A1 - Kleuser, Burkhard A1 - Edwards, Michael J. A1 - Gulbins, Erich T1 - Sphingosine-coating of plastic surfaces prevents ventilator-associated pneumonia JF - Journal of molecular medicine N2 - Ventilator-associated pneumonia (VAP) is a major cause of morbidity and mortality in critically ill patients. Here, we employed the broad antibacterial effects of sphingosine to prevent VAP by developing a novel method of coating surfaces of endotracheal tubes with sphingosine and sphingosine analogs. Sphingosine and phytosphingosine coatings of endotracheal tubes prevent adherence and mediate killing of Pseudomonas aeruginosa, Acinetobacter baumannii, and Staphylococcus aureus, even in biofilms. Most importantly, sphingosine-coating of endotracheal tubes also prevented P. aeruginosa and S. aureus pneumonia in vivo. Coating of the tubes with sphingosine was stable, without obvious side effects on tracheal epithelial cells and did not induce inflammation. In summary, we describe a novel method to coat plastic surfaces and provide evidence for the application of sphingosine and phytosphingosine as novel antimicrobial coatings to prevent bacterial adherence and induce killing of pathogens on the surface of endotracheal tubes with potential to prevent biofilm formation and VAP.Key messagesNovel dip-coating method to coat plastic surfaces with lipids.Sphingosine and phytosphingosine as novel antimicrobial coatings on plastic surface.Sphingosine coatings of endotracheal tubes prevent bacterial adherence and biofilms.Sphingosine coatings of endotracheal tubes induce killing of pathogens.Sphingosine coatings of endotracheal tubes ventilator-associated pneumonia. KW - Coating KW - Plastic surfaces KW - Sphingosine KW - Ventilation KW - Acinetobacter baumannii KW - Pseudomonas aeruginosa KW - Staphylococcus aureus Y1 - 2019 U6 - https://doi.org/10.1007/s00109-019-01800-1 SN - 0946-2716 SN - 1432-1440 VL - 97 IS - 8 SP - 1195 EP - 1211 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Sedaghatmehr, Mastoureh A1 - Thirumalaikumar, Venkatesh P. A1 - Kamranfar, Iman A1 - Marmagne, Anne A1 - Masclaux-Daubresse, Celine A1 - Balazadeh, Salma T1 - A regulatory role of autophagy for resetting the memory of heat stress in plants JF - Plant, cell & environment : cell physiology, whole-plant physiology, community physiology N2 - As sessile life forms, plants are repeatedly confronted with adverse environmental conditions, which can impair development, growth, and reproduction. During evolution, plants have established mechanisms to orchestrate the delicate balance between growth and stress tolerance, to reset cellular biochemistry once stress vanishes, or to keep a molecular memory, which enables survival of a harsher stress that may arise later. Although there are several examples of memory in diverse plants species, the molecular machinery underlying the formation, duration, and resetting of stress memories is largely unknown so far. We report here that autophagy, a central self-degradative process, assists in resetting cellular memory of heat stress (HS) in Arabidopsis thaliana. Autophagy is induced by thermopriming (moderate HS) and, intriguingly, remains high long after stress termination. We demonstrate that autophagy mediates the specific degradation of heat shock proteins at later stages of the thermorecovery phase leading to the accumulation of protein aggregates after the second HS and a compromised heat tolerance. Autophagy mutants retain heat shock proteins longer than wild type and concomitantly display improved thermomemory. Our findings reveal a novel regulatory mechanism for HS memory in plants. KW - Arabidopsis KW - heat shock proteins KW - priming KW - resetting Y1 - 2019 U6 - https://doi.org/10.1111/pce.13426 SN - 0140-7791 SN - 1365-3040 VL - 42 IS - 3 SP - 1054 EP - 1064 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Schöpke, Benito A1 - Heinze, Johannes A1 - Pätzig, Marlene A1 - Heinken, Thilo T1 - Do dispersal traits of wetland plant species explain tolerance against isolation effects in naturally fragmented habitats? JF - Plant ecology : an international journal N2 - The effects of habitat fragmentation and isolation on plant species richness have been verified for a wide range of anthropogenically fragmented habitats, but there is currently little information about their effects in naturally small and isolated habitats. We tested whether habitat area, heterogeneity, and isolation affect the richness of wetland vascular plant species in kettle holes, i.e., small glacially created wetlands, in an agricultural landscape of 1 km(2) in NE Germany. We compared fragmentation effects with those of forest fragments in the same landscape window. Since wetland and forest species might differ in their tolerance to isolation, and because isolation effects on plant species may be trait dependent, we asked which key life history traits might foster differences in isolation tolerance between wetland and forest plants. We recorded the flora and vegetation types in 83 isolated sites that contained 81 kettle holes and 25 forest fragments. Overall, the number of wetland species increased with increasing area and heterogeneity, i.e., the number of vegetation types, while area was not a surrogate for heterogeneity in these naturally fragmented systems. Isolation did not influence the number of wetland species but decreased the number of forest species. We also found that seeds of wetland species were on average lighter, more persistent and better adapted to epizoochory, e.g., by waterfowl, than seeds of forest species. Therefore, we suggest that wetland species are more tolerant to isolation than forest species due to their higher dispersal potential in space and time, which may counterbalance the negative effects of isolation. KW - Forest species KW - Habitat fragmentation KW - Isolation KW - Kettle holes KW - Life history traits KW - Wetland species Y1 - 2019 U6 - https://doi.org/10.1007/s11258-019-00955-8 SN - 1385-0237 SN - 1573-5052 VL - 220 IS - 9 SP - 801 EP - 815 PB - Springer CY - Dordrecht ER - TY - GEN A1 - Schälicke, Svenja A1 - Teubner, Johannes A1 - Martin-Creuzburg, Dominik A1 - Wacker, Alexander T1 - Fitness response variation within and among consumer species can be co-mediated by food quantity and biochemical quality T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - In natural heterogeneous environments, the fitness of animals is strongly influenced by the availability and composition of food. Food quantity and biochemical quality constraints may affect individual traits of consumers differently, mediating fitness response variation within and among species. Using a multifactorial experimental approach, we assessed population growth rate, fecundity, and survival of six strains of the two closely related freshwater rotifer species Brachionus calyciflorus sensu stricto and Brachionus fernandoi. Therefore, rotifers fed low and high concentrations of three algal species differing in their biochemical food quality. Additionally, we explored the potential of a single limiting biochemical nutrient to mediate variations in population growth response. Therefore, rotifers fed a sterol-free alga, which we supplemented with cholesterol-containing liposomes. Co-limitation by food quantity and biochemical food quality resulted in differences in population growth rates among strains, but not between species, although effects on fecundity and survival differed between species. The effect of cholesterol supplementation on population growth was strain-specific but not species-specific. We show that fitness response variations within and among species can be mediated by biochemical food quality. Dietary constraints thus may act as evolutionary drivers on physiological traits of consumers, which may have strong implications for various ecological interactions. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 806 KW - Polyunsaturated Fatty-Acids KW - Life-History Consequences KW - 2 Different Strains KW - Population-Growth KW - Resource Competition KW - Body-Size KW - Egg Size KW - Rotifier KW - Limitation KW - Carbon Y1 - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-442256 SN - 1866-8372 IS - 806 ER - TY - JOUR A1 - Schälicke, Svenja A1 - Teubner, Johannes A1 - Martin-Creuzburg, Dominik A1 - Wacker, Alexander T1 - Fitness response variation within and among consumer species can be co-mediated by food quantity and biochemical quality JF - Scientific Reports N2 - In natural heterogeneous environments, the fitness of animals is strongly influenced by the availability and composition of food. Food quantity and biochemical quality constraints may affect individual traits of consumers differently, mediating fitness response variation within and among species. Using a multifactorial experimental approach, we assessed population growth rate, fecundity, and survival of six strains of the two closely related freshwater rotifer species Brachionus calyciflorus sensu stricto and Brachionus fernandoi. Therefore, rotifers fed low and high concentrations of three algal species differing in their biochemical food quality. Additionally, we explored the potential of a single limiting biochemical nutrient to mediate variations in population growth response. Therefore, rotifers fed a sterol-free alga, which we supplemented with cholesterol-containing liposomes. Co-limitation by food quantity and biochemical food quality resulted in differences in population growth rates among strains, but not between species, although effects on fecundity and survival differed between species. The effect of cholesterol supplementation on population growth was strain-specific but not species-specific. We show that fitness response variations within and among species can be mediated by biochemical food quality. Dietary constraints thus may act as evolutionary drivers on physiological traits of consumers, which may have strong implications for various ecological interactions. KW - Polyunsaturated Fatty-Acids KW - Life-History Consequences KW - 2 Different Strains KW - Population-Growth KW - Resource Competition KW - Body-Size KW - Egg Size KW - Rotifier KW - Limitation KW - Carbon Y1 - 2019 U6 - https://doi.org/10.1038/s41598-019-52538-2 SN - 2045-2322 VL - 9 PB - Macmillan Publishers Limited CY - London ER - TY - JOUR A1 - Schälicke, Svenja A1 - Sobisch, Lydia-Yasmin A1 - Martin-Creuzburg, Dominik A1 - Wacker, Alexander T1 - Food quantity-quality co-limitation BT - interactive effects of dietary carbon and essential lipid supply on population growth of a freshwater rotifer JF - Freshwater biology N2 - Food quantity and quality are highly variable in natural systems. Therefore, their interplay and the associated effects on consumer population growth are important for predator-prey interactions and community dynamics. Experiments in which consumers were exposed to elemental nutrient limitations along food quantity gradients suggest that food quality effects on consumer performance are relevant only at high food quantities. However, elemental nutrients act differently on physiological processes than biochemical nutrients. So far, the interactive effects of food quantity and biochemical compounds on consumer performance have been insufficiently studied. We studied interactive effects of food quantity and biochemical food quality on population growth, including fecundity and survival, of the freshwater rotifer Brachionus calyciflorus. We hypothesised that these life history traits are differently affected by the availability of biochemical nutrients and that food quality effects gain importance with increasing food quantity. In a first experiment, we established food quantity and quality gradients by providing rotifers with different concentrations of a low-quality food, the sterol-free cyanobacterium Synechococcus elongatus, supplemented with increasing amounts of cholesterol. In a second experiment, food quantity and quality gradients were established by providing different proportions of two prey species differing in biochemical food quality, i.e. S.elongatus and the lipid-rich alga Nannochloropsis limnetica, at different total food concentrations. We found that the effects of cholesterol supplementation on population growth increased with increasing food quantity. This interactive effect on population growth was mainly due to food quality effects on fecundity, as effects on survival remained constant along the food quantity gradient. In contrast, when feeding on the mixed algal diet, the food quality effect associated with increasing the proportion of the high-quality alga did not change along the food quantity gradient. The data on survival and fecundity demonstrate the missing interactive effect of food quantity and quality on population growth, as both traits were oppositely affected. Survival was affected by food quality primarily at low food quantity, whereas food quality effects on fecundity were stronger at high food quantity. Our results highlight the significance of essential biochemicals in mediating the interactive effects of food quantity and quality on population growth. The interplay between food quantity and biochemical food quality limitation seems to influence resource allocation patterns in order to optimise survival or reproduction, which may strongly affect population dynamics in variable environments. As opposed to exploring the function of a single nutrient via supplementation, using algae mixtures allowed us to assess food quality effects on consumer performance in a more natural context by taking potential interactive effects of multiple co-limiting nutrients into account. KW - Brachionus calyciflorus KW - fecundity KW - population growth rate KW - sterols KW - survival Y1 - 2019 U6 - https://doi.org/10.1111/fwb.13272 SN - 0046-5070 SN - 1365-2427 VL - 64 IS - 5 SP - 903 EP - 912 PB - Wiley CY - Hoboken ER - TY - THES A1 - Schäfer, Merlin T1 - Understanding and predicting global change impacts on migratory birds T1 - Verständnis und Vorhersage von Auswirkungen des globalen Wandels auf Zugvögel N2 - This is a publication-based dissertation comprising three original research stud-ies (one published, one submitted and one ready for submission; status March 2019). The dissertation introduces a generic computer model as a tool to investigate the behaviour and population dynamics of animals in cyclic environments. The model is further employed for analysing how migratory birds respond to various scenarios of altered food supply under global change. Here, ecological and evolutionary time-scales are considered, as well as the biological constraints and trade-offs the individual faces, which ultimately shape response dynamics at the population level. Further, the effect of fine-scale temporal patterns in re-source supply are studied, which is challenging to achieve experimentally. My findings predict population declines, altered behavioural timing and negative carry-over effects arising in migratory birds under global change. They thus stress the need for intensified research on how ecological mechanisms are affected by global change and for effective conservation measures for migratory birds. The open-source modelling software created for this dissertation can now be used for other taxa and related research questions. Overall, this thesis improves our mechanistic understanding of the impacts of global change on migratory birds as one prerequisite to comprehend ongoing global biodiversity loss. The research results are discussed in a broader ecological and scientific context in a concluding synthesis chapter. N2 - Dies ist eine publikationsbasierte Dissertation, welche aus drei wissenschaftlichen Originalstudien (eine publiziert, eine eingereicht und eine einreichbar; Stand März 2019) besteht. Die Dissertation stellt ein generisches Computermodell bereit, um das Verhalten und die Populationsdynamik von Tieren zu untersuchen, welche saisonale Umweltbedingungen erfahren. Mit diesem Computermodell untersuche ich in der vorliegenden Thesis, wie Zugvögel auf verschiedene Szenarien veränderter Nahrungsverfügbarkeit reagieren, welche im Rahmen des globalen Wandels wahrscheinlich sind. Dabei werden ökologische und evolutionäre Zeitskalen berücksichtigt. Außerdem werden biologisch bedingte Einschränkungen und Zielkonflikte einbezogen, welche das einzelne Individuum erfährt, die aber letztendlich auch das Geschehen auf Populationsebene bestimmen. Weiterhin studiere ich mit dem erstellten Computermodell am Beispiel des Weißstorchs, wie sich feinskalige Zeitmuster in der Nahrungsverfügbarkeit auf Zugvögel auswirken. Solche Studien würden eine enorme experimentelle Herausforderung darstellen. Die im Rahmen dieser Dissertation entstandene frei verfügbare Modellierungs-Software kann nun für andere Taxa und verwandte Forschungsfragen eingesetzt werden. Nach meinen Ergebnissen ist im Zuge des globalen Wandels mit verstärkten Populationsabnahmen bei Zugvögeln zu rechnen, sowie mit Änderungen im zeitlichen Verhaltensablauf und nichtlinearen negativen Carry-over-Effekten. Dies verdeutlicht, wie wichtig es ist, die vom globalen Wandel betroffenen ökologischen Mechanismen näher zu erforschen sowie effektive Schutzmaßnahmen für Zugvögel zu entwickeln. Allgemein erhöht die Dissertation unser mechanistisches Verständnis davon, wie sich der globale Wandel auf bedrohte Zugvogelarten auswirkt und damit die globale Biodiversität beeinflusst. Die Forschungsergebnisse werden in einem abschließenden Synthese-Kapitel zusammenführend diskutiert. KW - global change KW - migratory birds KW - life-history theory KW - movement ecology KW - bird migration KW - optimal annual routine model KW - stochastic dynamic programming KW - full annual cycle KW - population dynamics KW - carry-over effects KW - white stork KW - behavioural ecology KW - adaptation KW - mechanistic model KW - energetics KW - behavioural timing KW - reproduction KW - globaler Wandel KW - Zugvögel KW - Lebenszyklustheorie KW - Bewegungsökologie KW - Vogelzug KW - "Optimal annual routine"-Modell KW - stochastisch-dynamische Optimierung KW - vollständiger Jahreszyklus KW - Populationsdynamik KW - Carry-over-Effekte KW - Weißstorch KW - Verhaltensökologie KW - Anpassung KW - mechanistisches Modell KW - Energetik KW - Verhaltens-Timing KW - Reproduktion Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-439256 ER - TY - JOUR A1 - Schäfer, Merlin T1 - Mut macht einsam BT - der Einfluss von Persönlichkeit auf das Zusammenleben von Tieren JF - Vielfalt in der Uckermark : Forschungsprojekte 2015 - 2018 Y1 - 2019 SP - 52 EP - 53 PB - oerding print GmbH CY - Braunschweig ER - TY - THES A1 - Schwuchow, Viola T1 - Charakterisierung der periplasmatischen Aldehyd-Oxidoreduktase (PaoABC) aus Escherichia coli N2 - Im Mittelpunkt dieser Arbeit standen Analysen zur Charakterisierung der periplasmatischen Aldehyd Oxidoreduktase aus E. coli. Kinetische Untersuchungen mit Ferricyanid als Elektronenakzeptor unter anaeroben Bedingungen zeigten für dieses Enzym eine höhere Aktivität als unter aeroben Bedingungen. Die getroffene Hypothese, dass PaoABC fähig ist Elektronen an molekularen Sauerstoff weiter zu geben, konnte bestätigt werden. Für den Umsatz aromatischer Aldehyde mit molekularem Sauerstoff wurde ein Optimum von pH 6,0 ermittelt. Dies steht im Gegensatz zur Reaktion mit Ferricyanid, mit welchem ein pH-Optimum von 4,0 gezeigt wurde. Die Reaktion von PaoABC mit molekularem Sauerstoff generiert zwar Wasserstoffperoxid, die Produktion von Superoxid konnte dagegen nicht beobachtet werden. Dass aerobe Bedingungen einen Einfluss auf das Auslösen der Expression von PaoABC haben, wurde in dieser Arbeit ebenfalls ermittelt. Im Zusammenhang mit der Produktion von ROS durch PaoABC wurde die Funktion eines kürzlich in Elektronentransfer-Distanz zum FAD identifizierten [4Fe4S]-Clusters untersucht. Ein Austausch der für die Bindung des Clusters zuständigen Cysteine führte zur Instabilität der Proteinvarianten, weswegen für diese keine weiteren Untersuchungen erfolgten. Daher wird zumindest ein struktur-stabilisierender Einfluss des [4Fe4S]-Clusters angenommen. Zur weiteren Untersuchung der Funktion dieses Clusters, wurde ein zwischen FAD und [4Fe4S]-Cluster lokalisiertes Arginin gegen ein Alanin ausgetauscht. Diese Proteinvariante zeigte eine reduzierte Geschwindigkeit der Reaktion gegenüber dem Wildtyp. Die Bildung von Superoxid konnte auch hier nicht beobachtet werden. Die Vermutung, dass dieser Cluster einen elektronen-sammelnden Mechanismus unterstützt, welcher die Radikalbildung verhindert, kann trotz allem nicht ausgeschlossen werden. Da im Umkreis des Arginins weitere geladene und aromatische Aminosäuren lokalisiert sind, können diese den notwendigen Elektronentransfer übernehmen. Neben der Ermittlung eines physiologischen Elektronenakzeptors und dessen Einfluss auf die Expression von PaoABC zeigt diese Arbeit auch, dass die Chaperone PaoD und MocA während der Reifung des MCD-Kofaktor eine gemeinsame Bindung an PaoABC realisieren. Es konnte im aktiven Zentrum von PaoABC ein Arginin beschrieben werden, welches auf Grund der engen Nachbarschaft zum MCD-Kofaktor und zum Glutamat (PaoABC-EC692) am Prozess der Substratbindung beteiligt ist. Im Zusammenhang mit dem Austausch dieses Arginins gegen ein Histidin oder ein Lysin wurden die Enzymspezifität und der Einfluss physiologischer Bedingungen, wie pH und Ionenstärke, auf die Reaktion des Enzyms untersucht. Gegenüber dem Wildtyp zeigten die Varianten mit molekularem Sauerstoff eine geringere Affinität zum Substrat aber auch eine höhere Geschwindigkeit der Reaktion. Vor allem für die Histidin-Variante konnte im gesamten pH-Bereich ein instabiles Verhalten bestimmt werden. Der Grund dafür wurde durch das Lösen der Struktur der Histidin-Variante beschreiben. Durch den Austausch der Aminosäuren entfällt die stabilisierende Wirkung der delokalisierten Elektronen des Arginins und es kommt zu einer Konformationsänderung im aktiven Zentrum. Neben der Reaktion von PaoABC mit einer Vielzahl aromatischer Aldehyde konnte auch der Umsatz von Salicylaldehyd zu Salicylsäure durch PaoABC in einer Farbreaktion bestimmt werden. Durch Ausschluss von molekularem Sauerstoff als terminaler Elektronenakzeptor, in einer enzym-gekoppelten Reaktion, erfolgte ein Elektronentransport auf Ferrocencarboxylsäure. Die Kombination aus beiden Methoden ermöglichte eine Verwendung von Ferrocen-Derivaten zur Generierung einer enzym-gekoppelten Reaktion mit PaoABC. Die Untersuchungen zu PaoABC zeigen, dass die Vielfalt der durch das Enzym katalysierten Rektionen weitere Möglichkeiten der enzymatischen Bestimmung biokatalytischer Prozesse bietet. KW - Eschericha coli KW - Periplasma KW - Aldehydoxidase KW - Aldehyd KW - Oxidoreduktase KW - Molybdän Y1 - 2019 ER - TY - JOUR A1 - Schwarzer, Christian A1 - Joshi, Jasmin Radha T1 - Ecotypic differentiation, hybridization and clonality facilitate the persistence of a cold-adapted sedge in European bogs JF - Biological journal of the Linnean Society : a journal of evolution N2 - Recent research has shown that many cold-adapted species survived the last glacial maximum (LGM) in northern refugia. Whether this evolutionary history has had consequences for their genetic diversity and adaptive potential remains unknown. We sampled 14 populations of Carex limosa, a sedge specialized to bog ecosystems, along a latitudinal gradient from its Scandinavian core to the southern lowland range-margin in Germany. Using microsatellite and experimental common-garden data, we evaluated the impacts of global climate change along this gradient and assessed the conservation status of the southern marginal populations. Microsatellite data revealed two highly distinct genetic groups and hybrid individuals. In our common-garden experiment, the two groups showed divergent responses to increased nitrogen/phosphorus (N/P) availability, suggesting ecotypic differentiation. Each group formed genetically uniform populations at both northern and southern sampling areas. Mixed populations occurred throughout our sampling area, an area that was entirely glaciated during the LGM. The fragmented distribution implies allopatric divergence at geographically separated refugia that putatively differed in N/P availability. Molecular data and an observed low hybrid fecundity indicate the importance of clonal reproduction for hybrid populations. At the southern range-margin, however, all populations showed effects of clonality, lowered fecundity and low competitiveness, suggesting abiotic and biotic constraints to population persistence. KW - biogeography KW - bog/mire plants KW - Carex limosa KW - climate change KW - glacial divergence KW - global change KW - leading/trailing edge KW - population differentiation KW - sexual/asexual reproduction Y1 - 2019 U6 - https://doi.org/10.1093/biolinnean/blz141 SN - 0024-4066 SN - 1095-8312 VL - 128 IS - 4 SP - 909 EP - 925 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Schwarz, Maria A1 - Lossow, Kristina A1 - Kopp, Johannes Florian A1 - Schwerdtle, Tanja A1 - Kipp, Anna Patricia T1 - Crosstalk of Nrf2 with the Trace Elements Selenium, Iron, Zinc, and Copper JF - Nutrients N2 - Trace elements, like Cu, Zn, Fe, or Se, are important for the proper functioning of antioxidant enzymes. However, in excessive amounts, they can also act as pro-oxidants. Accordingly, trace elements influence redox-modulated signaling pathways, such as the Nrf2 pathway. Vice versa, Nrf2 target genes belong to the group of transport and metal binding proteins. In order to investigate whether Nrf2 directly regulates the systemic trace element status, we used mice to study the effect of a constitutive, whole-body Nrf2 knockout on the systemic status of Cu, Zn, Fe, and Se. As the loss of selenoproteins under Se-deprived conditions has been described to further enhance Nrf2 activity, we additionally analyzed the combination of Nrf2 knockout with feeding diets that provide either suboptimal, adequate, or supplemented amounts of Se. Experiments revealed that the Nrf2 knockout partially affected the trace element concentrations of Cu, Zn, Fe, or Se in the intestine, liver, and/or plasma. However, aside from Fe, the other three trace elements were only marginally modulated in an Nrf2-dependent manner. Selenium deficiency mainly resulted in increased plasma Zn levels. One putative mediator could be the metal regulatory transcription factor 1, which was up-regulated with an increasing Se supply and downregulated in Se-supplemented Nrf2 knockout mice. KW - Nrf2 KW - selenium KW - iron KW - copper KW - zinc KW - homeostasis Y1 - 2019 U6 - https://doi.org/10.3390/nu11092112 SN - 2072-6643 VL - 11 IS - 9 PB - MDPI CY - Basel ER - TY - GEN A1 - Schwarz, Maria A1 - Lossow, Kristina A1 - Kopp, Johannes F. A1 - Schwerdtle, Tanja A1 - Kipp, Anna Patricia T1 - Crosstalk of Nrf2 with the Trace Elements Selenium, Iron, Zinc, and Copper T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Trace elements, like Cu, Zn, Fe, or Se, are important for the proper functioning of antioxidant enzymes. However, in excessive amounts, they can also act as pro-oxidants. Accordingly, trace elements influence redox-modulated signaling pathways, such as the Nrf2 pathway. Vice versa, Nrf2 target genes belong to the group of transport and metal binding proteins. In order to investigate whether Nrf2 directly regulates the systemic trace element status, we used mice to study the effect of a constitutive, whole-body Nrf2 knockout on the systemic status of Cu, Zn, Fe, and Se. As the loss of selenoproteins under Se-deprived conditions has been described to further enhance Nrf2 activity, we additionally analyzed the combination of Nrf2 knockout with feeding diets that provide either suboptimal, adequate, or supplemented amounts of Se. Experiments revealed that the Nrf2 knockout partially affected the trace element concentrations of Cu, Zn, Fe, or Se in the intestine, liver, and/or plasma. However, aside from Fe, the other three trace elements were only marginally modulated in an Nrf2-dependent manner. Selenium deficiency mainly resulted in increased plasma Zn levels. One putative mediator could be the metal regulatory transcription factor 1, which was up-regulated with an increasing Se supply and downregulated in Se-supplemented Nrf2 knockout mice. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1081 KW - Nrf2 KW - selenium KW - iron KW - copper KW - zinc KW - homeostasis Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-472873 SN - 1866-8372 IS - 1081 ER - TY - JOUR A1 - Schwabe, Angelika A1 - Tischew, Sabine A1 - Bergmeier, Erwin A1 - Garve, Eckhard A1 - Härdtle, Werner A1 - Heinken, Thilo A1 - Hölzel, Norbert A1 - Peppler-Lisbach, Cord A1 - Remy, Dominique A1 - Dierschke, Hartmut T1 - Pflanzengesellschaft des Jahres 2020 BT - Borstgrasrasen JF - Tuexenia : Mitteilungen der Floristisch-Soziologischen Arbeitsgemeinschaft N2 - Wie erstmals 2019 wird auch für das Jahr 2020 von der „Floristisch-soziologischen Arbeitsgemeinschaft“ (FlorSoz) für Deutschland die „Pflanzengesellschaft des Jahres“ vorgestellt. Damit soll wiederum für die Öffentlichkeit die Notwendigkeit des Schutzes gefährdeter Pflanzengesellschaften aufgezeigt werden. Für das Jahr 2020 wurden die Borstgrasrasen ausgewählt. Wie alle Pflanzengemeinschaften nährstoffarmer Standorte, sind auch die Borstgrasrasen stark gefährdet und regional sogar unmittelbar vom Aussterben bedroht. Wir konzentrieren uns vor allem auf die Bestände der planaren bis montanen Stufe (Unterverband Violenion caninae: Hundsveilchen-Borstgrasrasen). Die Standorte von Violenion caninae-Gesellschaften werden nicht gedüngt und sind auf extensive Beweidung, z.T. auch auf einschürige Mahd angewiesen. Für Borstgrasrasen bezeichnend sind eine Fülle gefährdeter Pflanzenarten wie z.B. Arnica montana (Arnika) und Antennaria dioica (Zweihäusiges Katzenpfötchen). Bei den Borstgrasrasen spielen für die zunehmend hohe Gefährdung nicht nur Flächenrückgänge durch Nutzungsaufgabe, Aufforstung, Sport- und Freizeitaktivitäten und Überbauung eine Rolle, sondern auch Änderungen der Struktur und Artenzusammensetzung durch direkte Düngung sowie atmogene Stickstoffeinträge sind von Bedeutung. Nährstoffanreicherungen führen zum Verlust der konkurrenzschwachen, gefährdeten Arten zugunsten einiger allgemein verbreiteter, häufig dominanter Gräser sowie konkurrenzkräftiger Kräuter. Wir skizzieren die Bedeutung der Borstgrasrasen als gefährdete Lebensgemeinschaften, geben Hinweise zur floristisch-soziologischen Erforschung und zu weiteren Naturschutz-Aspekten (Rückgang, Erhaltung, Möglichkeiten der Restitution). Ein wirksamer Schutz ist nur bei einem integrativen Naturschutzansatz mit geeigneter Nutzung möglich. N2 - As for the first time in 2019 the ‘Floristisch-soziologische Arbeitsgemeinschaft (FlorSoz)’ intro-duces the ‘Plant Community of the Year 2020’ for Germany. The FlorSoz proposal aims to alert the public that the conservation of endangered plant communities and their biodiversity is essential.For the year 2020 the plant community of mat-grass swards (Nardus stricta grassland) has been selected. Similar to other plant communities on nutrient-poor sites, Nardus grassland is highly endan-gered and in some regions on the brink of extinction. We focus on Nardus grassland of the lowland to montane levels with the characteristic Violenion caninae suballiance (named after Viola canina,the Heath Dog-violet). The sites of Violenion caninae communities are not fertilized and depend on extensive grazing, but there are also mat-grass swards which are mown once a year. Nardus grasslands host many threatened species, e.g., Arnica montana (Arnica) and Antennaria dioica (Mountain Everlasting).The decline of Nardus grassland is not only due to abandonment, afforestation, outdoor activities and construction measures, but also due to changes in the structure and species composition through eutrophication by either direct manuring or by atmospheric nitrogen input. Eutrophication causes local decline or extinction of low-competitive, often endangered species which are replaced by ubiquists, mostly highly competitive species. For management, long-term conservation practices like extensive grazing or cutting once a year are essential. We give an outline of Nardus grassland as an endangered habitat type and summarize its current state of ecological and phytosociological research. In particular we take up the issue of conservation, including the loss of Nardus grasslands and their restoration. Effective conservation depends on an integrative nature-conservation approach, using suitable man-agement practices. Y1 - 2019 U6 - https://doi.org/10.14471/2019.39.017 SN - 0722-494X IS - 39 SP - 287 EP - 308 PB - Floristisch-soziologischen Arbeitsgemeinschaft e.V. CY - Göttingen ER - TY - THES A1 - Schumacher, Julia T1 - Regulation and function of STERILE APETALA in Arabidopsis flower development N2 - STERILE APETALA (SAP) is known to be an essential regulator of flower development for over 20 years. Loss of SAP function in the model plant Arabidopsis thaliana is associated with a reduction of floral organ number, size and fertility. In accordance with the function of SAP during early flower development, its spatial expression in flowers is confined to meristematic stages and to developing ovules. However, to date, despite extensive research, the molecular function of SAP and the regulation of its spatio-temporal expression still remain elusive. In this work, amino acid sequence analysis and homology modeling revealed that SAP belongs to the rare class of plant F-box proteins with C-terminal WD40 repeats. In opisthokonts, this type of F-box proteins constitutes the substrate binding subunit of SCF complexes, which catalyze the ubiquitination of proteins to initiate their proteasomal degradation. With LC-MS/MS-based protein complex isolation, the interaction of SAP with major SCF complex subunits was confirmed. Additionally, candidate substrate proteins, such as the growth repressor PEAPOD 1 and 2 (PPD1/2), could be revealed during early stages of flower development. Also INDOLE-3-BUTYRIC ACID RESPONSE 5 (IBR5) was identified among putative interactors. Genetic analyses indicated that, different from substrate proteins, IBR5 is required for SAP function. Protein complex isolation together with transcriptome profiling emphasized that the SCFSAP complex integrates multiple biological processes, such as proliferative growth, vascular development, hormonal signaling and reproduction. Phenotypic analysis of sap mutant and SAP overexpressing plants positively correlated SAP function with plant growth during reproductive and vegetative development. Furthermore, to elaborate on the transcriptional regulation of SAP, publicly available ChIP-seq data of key floral homeotic proteins were reanalyzed. Here, it was shown that the MADS-domain transcription factors APETALA 1 (AP1), APETALA 3 (AP3), PISTILLATA (PI), AGAMOUS (AG) and SEPALLATA 3 (SEP3) bind to the SAP locus, which indicates that SAP is expressed in a floral organ-specific manner. Reporter gene analyses in combination with CRISPR/Cas9-mediated deletion of putative regulatory regions further demonstrated that the intron contains major regulatory elements of SAP in Arabidopsis thaliana. In conclusion, these data indicate that SAP is a pleiotropic developmental regulator that acts through tissue-specific destabilization of proteins. The presumed transcriptional regulation of SAP by the floral MADS-domain transcription factors could provide a missing link between the specification of floral organ identity and floral organ growth pathways. KW - STERILE APETALA KW - SAP KW - flower development KW - organ size KW - F-box KW - WD40 KW - SCF complex KW - ubiquitin KW - proteasomal degradation KW - MADS Y1 - 2019 ER - TY - GEN A1 - Schorn, Sina A1 - Salman-Carvalho, Verena A1 - Littmann, Sten A1 - Ionescu, Danny A1 - Grossart, Hans-Peter A1 - Cypionka, Heribert T1 - Cell architecture of the giant sulfur bacterium achromatium oxaliferum BT - Extra-cytoplasmic localization of calcium carbonate bodies T2 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Achromatium oxaliferum is a large sulfur bacterium easily recognized by large intracellular calcium carbonate bodies. Although these bodies often fill major parts of the cells' volume, their role and specific intracellular location are unclear. In this study, we used various microscopy and staining techniques to identify the cell compartment harboring the calcium carbonate bodies. We observed that Achromatium cells often lost their calcium carbonate bodies, either naturally or induced by treatments with diluted acids, ethanol, sodium bicarbonate and UV radiation which did not visibly affect the overall shape and motility of the cells (except for UV radiation). The water-soluble fluorescent dye fluorescein easily diffused into empty cavities remaining after calcium carbonate loss. Membranes (stained with Nile Red) formed a network stretching throughout the cell and surrounding empty or filled calcium carbonate cavities. The cytoplasm (stained with FITC and SYBR Green for nucleic acids) appeared highly condensed and showed spots of dissolved Ca2+ (stained with Fura-2). From our observations, we conclude that the calcium carbonate bodies are located in the periplasm, in extra-cytoplasmic pockets of the cytoplasmic membrane and are thus kept separate from the cell's cytoplasm. This periplasmic localization of the carbonate bodies might explain their dynamic formation and release upon environmental changes. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1356 KW - sulfur-bacteria KW - calcium carbonate inclusions KW - extra-cytoplasmic pockets KW - calcite Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-549935 SN - 1866-8372 IS - 2 ER - TY - JOUR A1 - Schorn, Sina A1 - Salman-Carvalho, Verena A1 - Littmann, Sten A1 - Ionescu, Danny A1 - Grossart, Hans-Peter A1 - Cypionka, Heribert T1 - Cell architecture of the giant sulfur bacterium achromatium oxaliferum BT - Extra-cytoplasmic localization of calcium carbonate bodies JF - FEMS Microbiology Ecology N2 - Achromatium oxaliferum is a large sulfur bacterium easily recognized by large intracellular calcium carbonate bodies. Although these bodies often fill major parts of the cells' volume, their role and specific intracellular location are unclear. In this study, we used various microscopy and staining techniques to identify the cell compartment harboring the calcium carbonate bodies. We observed that Achromatium cells often lost their calcium carbonate bodies, either naturally or induced by treatments with diluted acids, ethanol, sodium bicarbonate and UV radiation which did not visibly affect the overall shape and motility of the cells (except for UV radiation). The water-soluble fluorescent dye fluorescein easily diffused into empty cavities remaining after calcium carbonate loss. Membranes (stained with Nile Red) formed a network stretching throughout the cell and surrounding empty or filled calcium carbonate cavities. The cytoplasm (stained with FITC and SYBR Green for nucleic acids) appeared highly condensed and showed spots of dissolved Ca2+ (stained with Fura-2). From our observations, we conclude that the calcium carbonate bodies are located in the periplasm, in extra-cytoplasmic pockets of the cytoplasmic membrane and are thus kept separate from the cell's cytoplasm. This periplasmic localization of the carbonate bodies might explain their dynamic formation and release upon environmental changes. KW - sulfur-bacteria KW - calcium carbonate inclusions KW - extra-cytoplasmic pockets KW - calcite Y1 - 2019 U6 - https://doi.org/10.1093/femsec/fiz200 SN - 1574-6941 VL - 96 IS - 2 SP - 1 EP - 8 PB - Oxford University Press CY - Oxford ER - TY - JOUR A1 - Schoenauer, Roman A1 - Larpin, Yu A1 - Babiychuk, Eduard B. A1 - Drucker, Patrick A1 - Babiychuk, Viktoriia S. A1 - Avota, Elita A1 - Schneider-Schaulies, Sibylle A1 - Schumacher, Fabian A1 - Kleuser, Burkhard A1 - Koffel, Rene A1 - Draeger, Annette T1 - Down-regulation of acid sphingomyelinase and neutral sphingomyelinase-2 inversely determines the cellular resistance to plasmalemmal injury by pore-forming toxins JF - The FASEB journal : the official journal of the Federation of American Societies for Experimental Biology N2 - Bacterial pore-forming toxins compromise plasmalemmal integrity, leading to Ca2+ influx, leakage of the cytoplasm, and cell death. Such lesions can be repaired by microvesicular shedding or by the endocytic uptake of the injured membrane sites. Cells have at their disposal an entire toolbox of repair proteins for the identification and elimination of membrane lesions. Sphingomyelinases catalyze the breakdown of sphingomyelin into ceramide and phosphocholine. Sphingomyelin is predominantly localized in the outer leaflet, where it is hydrolyzed by acid sphingomyelinase (ASM) after lysosomal fusion with the plasma membrane. The magnesium-dependent neutral sphingomyelinase (NSM)-2 is found at the inner leaflet of the plasmalemma. Because either sphingomyelinase has been ascribed a role in the cellular stress response, we investigated their role in plasma membrane repair and cellular survival after treatment with the pore-forming toxins listeriolysin O (LLO) or pneumolysin (PLY). Jurkat T cells, in which ASM or NSM-2 was down-regulated [ASM knockdown (KD) or NSM-2 KD cells], showed inverse reactions to toxin-induced membrane damage: ASM KD cells displayed reduced toxin resistance, decreased viability, and defects in membrane repair. In contrast, the down-regulation of NSM-2 led to an increase in viability and enhanced plasmalemmal repair. Yet, in addition to the increased plasmalemmal repair, the enhanced toxin resistance of NSM-2 KD cells also appeared to be dependent on the activation of p38/MAPK, which was constitutively activated, whereas in ASM KD cells, the p38/MAPK activation was constitutively blunted.Schoenauer, R., Larpin, Y., Babiychuk, E. B., Drucker, P., Babiychuk, V. S., Avota, E., Schneider-Schaulies, S., Schumacher, F., Kleuser, B., Koffel, R., Draeger, A. Down-regulation of acid sphingomyelinase and neutral sphingomyelinase-2 inversely determines the cellular resistance to plasmalemmal injury by pore-forming toxins. KW - membrane repair KW - blebbing KW - calcium KW - bacterial toxins KW - annexins Y1 - 2018 U6 - https://doi.org/10.1096/fj.201800033R SN - 0892-6638 SN - 1530-6860 VL - 33 IS - 1 SP - 275 EP - 285 PB - Federation of American Societies for Experimental Biology CY - Bethesda ER - TY - JOUR A1 - Schlägel, Ulrike E. A1 - Signer, Johannes A1 - Herde, Antje A1 - Eden, Sophie A1 - Jeltsch, Florian A1 - Eccard, Jana A1 - Dammhahn, Melanie T1 - Estimating interactions between individuals from concurrent animal movements JF - Methods in ecology and evolution : an official journal of the British Ecological Society N2 - Animal movements arise from complex interactions of individuals with their environment, including both conspecific and heterospecific individuals. Animals may be attracted to each other for mating, social foraging, or information gain, or may keep at a distance from others to avoid aggressive encounters related to, e.g., interference competition, territoriality, or predation. With modern tracking technology, more datasets are emerging that allow to investigate fine‐scale interactions between free‐ranging individuals from movement data, however, few methods exist to disentangle fine‐scale behavioural responses of interacting individuals when these are highly individual‐specific. In a framework of step‐selection functions, we related movements decisions of individuals to dynamic occurrence distributions of other individuals obtained through kriging of their movement paths. Using simulated data, we tested the method's ability to identify various combinations of attraction, avoidance, and neutrality between individuals, including asymmetric (i.e. non‐mutual) behaviours. Additionally, we analysed radio‐telemetry data from concurrently tracked small rodents (bank vole, Myodes glareolus) to test whether our method could detect biologically plausible behaviours. We found that our method was able to successfully detect and distinguish between fine‐scale interactions (attraction, avoidance, neutrality), even when these were asymmetric between individuals. The method worked best when confounding factors were taken into account in the step‐selection function. However, even when failing to do so (e.g. due to missing information), interactions could be reasonably identified. In bank voles, responses depended strongly on the sexes of the involved individuals and matched expectations. Our approach can be combined with conventional uses of step‐selection functions to tease apart the various drivers of movement, e.g. the influence of the physical and the social environment. In addition, the method is particularly useful in studying interactions when responses are highly individual‐specific, i.e. vary between and towards different individuals, making our method suitable for both single‐species and multi‐species analyses (e.g. in the context of predation or competition). KW - attraction-avoidance KW - fine-scale interactions KW - individual variability KW - inter-specific interactions KW - movement behaviour KW - occurrence estimates KW - social environment KW - step-selection function Y1 - 2019 U6 - https://doi.org/10.1111/2041-210X.13235 SN - 2041-210X SN - 2041-2096 VL - 10 IS - 8 SP - 1234 EP - 1245 PB - Wiley CY - Hoboken ER - TY - CHAP A1 - Schlaad, Helmut A1 - Luedecke, Nils T1 - Bio-sourced chelating poly(2-oxazoline)s T2 - Abstracts of papers : joint conference / The Chemical Institute of Cananda, CIC, American Chemical Society, ACS Y1 - 2019 SN - 0065-7727 VL - 257 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Schiro, Gabriele A1 - Colangeli, Pierluigi A1 - Müller, Marina E. H. T1 - A Metabarcoding Analysis of the Mycobiome of Wheat Ears Across a Topographically Heterogeneous Field JF - Frontiers in microbiology KW - Fusarium KW - microclimate KW - canopy KW - fungal community KW - Alternaria KW - spatially induced variance Y1 - 2019 U6 - https://doi.org/10.3389/fmicb.2019.02095 SN - 1664-302X VL - 10 PB - Frontiers Research Foundation CY - Lausanne ER - TY - THES A1 - Schiro, Gabriele T1 - Spatial distribution of phyllosphere fungi in topographically heterogeneous wheat fields BT - an analysis of abiotic and biotic driving factors Y1 - 2019 ER - TY - JOUR A1 - Schirmer, Annika A1 - Herde, Antje A1 - Eccard, Jana A1 - Dammhahn, Melanie T1 - Individuals in space: personality-dependent space use, movement and microhabitat use facilitate individual spatial niche specialization JF - Oecologia N2 - Personality-dependent space use and movement might be crucially influencing ecological interactions, giving way to individual niche specialization. This new approach challenges classical niche theory with potentially great ecological consequences, but so far has only scarce empirical support. Here, we investigated if and how consistent inter-individual differences in behavior predict space use and movement patterns in free-ranging bank voles (Myodes glareolus) and thereby contribute to individual niche specialization. Individuals were captured and marked from three different subpopulations in North-East Germany. Inter-individual differences in boldness and exploration were quantified via repeated standardized tests directly in the field after capture. Subsequently, space use and movement patterns of a representative sample of the behavioral variation (n=21 individuals) were monitored via automated VHF telemetry for a period of four days, yielding on average 384 locations per individual. Bolder individuals occupied larger home ranges and core areas (estimated via kernel density analyses), moved longer distances, spatially overlapped with fewer conspecifics and preferred different microhabitats based on vegetation cover compared to shyer individuals. We found evidence for personality-dependent space use, movement, and occupation of individual spatial niches in bank voles. Thus, besides dietary niche specialization also spatial dimensions of ecological niches vary among individuals within populations, which may have important consequences for ecological interactions within- and between species. KW - Ecological niche KW - Inter-individual differences KW - Intraspecific competition KW - Movement ecology KW - Small mammal Y1 - 2019 U6 - https://doi.org/10.1007/s00442-019-04365-5 SN - 0029-8549 SN - 1432-1939 VL - 189 IS - 3 SP - 647 EP - 660 PB - Springer CY - New York ER - TY - THES A1 - Schirmer, Annika T1 - Consistent individual differences in movement-related behaviour as equalising and/or stabilising mechanisms for species coexistence T1 - Konstante individuelle Unterschiede in Bewegungs-relevanten Verhaltensweisen als stabilisierende und/oder angleichende Mechanismen für die Koexistenz von Arten N2 - The facilitation of species coexistence has been a central theme in ecological research for years, highlighting two key aspects: ecological niches and competition between species. According to the competitive exclusion principle, the overlap of species niches predicts the amount of shared resources and therefore competition between species, determining their ability to coexist. Only if niches of two species are sufficiently different, thus niche overlap is low, competition within species is higher than competition between species and stable coexistence is possible. Thereby, differences in species mean traits are focused on and conspecific individuals are assumed to be interchangeable. This approach might be outdated since behaviour, as a key aspect mediating niche differentiation between species, is individual based. Individuals from one species consistently differ across time and situations in their behavioural traits. Causes and consequences of consistent behavioural differences have been thoroughly investigated stimulating their recent incorporation into ecological interactions and niche theory. Spatial components have so far been largely overlooked, although animal movement is strongly connected to several aspects of ecological niches and interactions between individuals. Furthermore, numerous movement aspects haven been proven to be crucially influenced by consistent individual differences. Considering spatial parameters could therefore crucially broaden our understanding of how individual niches are formed and ecological interactions are shaped. Furthermore, extending established concepts on species interactions by an individual component could provide new insights into how species coexistence is facilitated and local biodiversity is maintained. The main aim of this thesis was to test whether consistent inter-individual differences can facilitate the coexistence of ecological similar species. Therefore, the effects of consistent inter-individual differences on the spatial behaviour of two rodent species, the bank vole (Myodes glareolus) and the striped field mouse (Apodemus agrarius), were investigated and put in the context of: (i) individual spatial niches, (ii) interactions between species, and (iii) the importance of different levels of behavioural variation within species for their interactions. Consistent differences of study animals in boldness and exploration were quantified with the same tests in all presented studies and always combined with observations of movement and space use via automated VHF radio telemetry. Consequently, results are comparable throughout the thesis and the methods provide a common denominator for all chapters. The first two chapters are based on observations of free-ranging rodents in natural populations, while chapter III represents an experimental approach under semi-natural conditions. Chapter I focusses on the effect of consistent differences in boldness and exploration on movement and space use of bank voles and their contribution to individual spatial niche separation. Results show boldness to be the dominating predictor for spatial parameters in bank voles. Irrespective of sex, bolder individuals had larger home ranges, moved longer distances, had less spatial interactions with conspecifics and occupied different microhabitats compared to shy individuals. The same boldness-dependent spatial patterns could be observed in striped field mice which is reported in chapter II. Therefore, both study species showed individual spatial niche occupation. Chapter II builds on findings from the first chapter, investigating the effect of boldness driven individual spatial niche occupation on the interactions between species. Irrespective of species and sex, bolder individuals had more interspecific spatial interactions, but less intraspecific interactions, compared to shy individuals. Due to individual niches occupation the competitive environment individuals experience is not random. Interactions are restricted to individuals of similar behavioural type with presumably similar competitive ability, which could balance differences on the species level and support coexistence. In chapter III the experimental populations were either comprised of only shy or only bold bank voles, while striped field mice varied, creating either a shy- or bold-biased competitive community. Irrespective of behavioural type, striped field mice had more intraspecific interactions in bold-biased competitive communities. Only in a shy-biased competitive community, bolder striped field mice had less interspecific interactions compared to shy individuals. Bank voles showed no difference in intra- or interspecific interactions between populations. Chapter III highlights, that not only consistent inter-individual differences per se are important for interactions within and between species, but also the amount of behavioural variation within coexisting species. Overall, this thesis highlights the importance of considering consistent inter-individual differences in a spatial context and their connection to individual spatial niche occupation, as well as the resulting effects on interactions within and between species. Individual differences are discussed in the context of similarity of individuals, individual and species niche width, and individual and species niche overlap. Thereby, this thesis makes one step further from the existing research on individual niches towards integrating consistent inter-individual differences into the larger framework of species coexistence. N2 - Ein zentrales Thema in der Ökologie ist die Koexistenz von Arten. Zwei Aspekte sind dabei von großer Bedeutung: ökologische Nischen und zwischenartliche Konkurrenz. Das Konkurrenz-Ausschlussprinzip besagt, dass der Überlappungsgrad der Nischen zweier Arten bestimmt, wie viele Ressourcen sie teilen und damit wie stark die Konkurrenz zwischen ihnen ist. Eine stabile Koexistenz zweier Arten ist nur dann möglich, wenn ihre Nischen unterschiedlich genug sind und eine geringe Überlappung vorliegt. In diesem Fall ist die innerartliche Konkurrenz größer als die zwischenartliche, und die Bedingungen für eine langfristig stabile Koexistenz sind gegeben. Traditionell werden hierbei nur mittlere Unterschiede zwischen den Fokusarten verglichen und der Einfluss von Unterschieden zwischen Individuen nicht beachtet. Ein wesentlicher Aspekt, der die Nischendifferenzierung zwischen Tierarten beeinflusst ist deren Verhalten. Dieses ist jedoch nachweislich individuell geprägt, folglich könnte der oben erwähnte Ansatz zur Koexistenz von Arten eventuell veraltet sein. Zwischen Individuen einer Art gibt es konstante Verhaltensunterschiede, die stabil bleiben über die Zeit und zwischen verschiedenen Situationen. Ursachen und Effekte dieser Unterschiede wurden bereits in zahlreichen Tierarten untersucht, wodurch ebenfalls die Integration von individuellen Verhaltensunterschieden in das Konzept der ökologischen Nische angestoßen wurde. Aspekte der Raumnutzung von Tieren fanden hierbei bislang kaum Beachtung, obwohl sie für eine Vielzahl von Parametern, die mit Nischen in Verbindung stehen, essentiell sind. Räumliches Verhalten von Tieren wird stark durch individuelle Verhaltensunterschiede beeinflusst, weswegen es eine wichtige Rolle im Zusammenhang mit individuellen Nischen spielen sollte. Hinsichtlich der Formation individueller Nischen und ökologischer Interaktionen hat die Einbeziehung von räumlichen Aspekten das Potential entscheidende Impulse zu erbringen. Die Erweiterung bestehender Theorien zu Artinteraktionen, um eine individuelle Komponente, kann neue Einblicke schaffen wie Koexistenz zwischen Arten vermittelt und örtliche Biodiversität erhalten wird. Die hier vorliegende Arbeit befasst sich mit den Einflüssen von stabilen, individuellen Verhaltensunterschieden auf die Raumnutzung von Individuen. Dies wurde exemplarisch an zwei Nagerarten untersucht, der Rötelmaus (Myodes glareolus) und der Brandmaus (Apodemus agrarius). Dabei wird der Fokus auf die folgenden Aspekte gelegt: (i) individuelle Nischen, (ii) Interaktionen zwischen Arten, und (iii) Auswirkungen verschiedener Variationsgrade stabiler Verhaltensunterschiede auf die Interaktionen innerhalb und zwischen Arten. Alle Kapitel basieren auf der gleichen Methodik in der Datenaufnahme, da individuelle Verhaltensunterschiede stets mit dem gleichen Test quantifiziert und mit räumlichen Mustern in Zusammenhang gebracht wurden, die mit Hilfe automatischer VHF Radiotelemetrie aufgezeichnet wurden. Ergebnisse sind somit auch kapitelübergreifend vergleichbar. Kapitel eins und zwei umfassen Studien an freilebenden Nagetieren aus natürlichen Populationen, während das dritte Kapitel eine experimentelle Studie unter naturnahen Bedingungen darstellt. Das erste Kapitel handelt von den Effekten stabiler Verhaltensunterschiede in der Risikobereitschaft und dem Explorationsverhalten von Rötelmäusen auf deren Bewegungsmuster. Letztere wurden nur durch die Risikobereitschaft der Individuen beeinflusst, aber nicht durch deren Explorationsverhalten. Risikofreudigere Individuen hatten größere Streifgebiete, legten längere Strecken zurück, hatten weniger innerartliche Interaktionen und bewohnten andere Mikrohabitate als risikoscheue Individuen. Gleiche Muster konnten für die Brandmäuse gefunden werden, werden jedoch erst im zweiten Kapitel dargestellt. Beide Arten besetzen somit individuelle räumliche Nischen. Kapitel zwei baut auf dem Resultat des ersten Kapitels auf und beschäftigt sich mit den Auswirkungen von individuellen räumlichen Nischen auf die Interaktionen zwischen zwei Arten. Hierbei konnte gezeigt werden, dass unabhängig von Art und Geschlecht, risikofreudigere Individuen weniger innerartliche Interaktionen haben, dafür aber mehr zwischenartliche im Vergleich zu risikoscheuen Individuen. Die Besetzung individueller Nischen hat somit zur Folge, dass das Konkurrenz-Umfeld der Individuen abhängig von ihrem Verhaltenstyp ist. Daraus folgt, dass die Interaktionen zwischen Individuen zweier Arten beschränkt sind auf solche Individuen, die sich in ihrem Verhaltenstyp, und damit ihrer Konkurrenzkraft, ähneln. Etwaige Artunterschiede in der Konkurrenzkraft könnten dadurch ausgeglichen werden und die Koexistenz der Arten vermitteln. Im letzten Kapitel wurden experimentelle Populationen aus beiden Versuchsarten zusammengestellt. Diese unterschieden sich darin, dass die Rötelmäuse entweder ausschließlich risikoscheu oder risikobereit waren, während die Brandmäuse in ihrem Verhaltenstyp variierten. Dadurch wurden Artgemeinschaften erstellt, die entweder ein vorwiegend risikoscheues oder risikobereites Konkurrenz-Umfeld hatten. Eine reduzierte Variationsbreite der individuellen Verhaltensunterschiede in einer von zwei koexistierenden Arten führt dazu, dass sich die Interaktionsmuster innerhalb und zwischen den Arten, im Vergleich zu denen aus natürlichen Populationen verändern. Brandmäuse in einem risikobereiten Konkurrenz-Umfeld hatten mehr innerartliche Interaktionen als solche in einem risikoscheuen Konkurrenz-Umfeld, unabhängig davon ob die Brandmäuse selber risikoscheu oder risikofreudig waren. Die zwischenartlichen Interaktionen dagegen wurden nur in einem risikoscheuen Konkurrenz-Umfeld von risikobereiten Brandmäusen reduziert im Gegensatz zu risikoscheuen Individuen. Währenddessen zeigen Rötelmäuse weder in den inner- noch in den zwischenartlichen Interaktionen einen Unterschied aufgrund ihres Konkurrenz-Umfeldes. Das dritte Kapitel zeigt damit deutlich, dass nicht nur stabile individuelle Unterschiede für inner- und zwischenartliche Interaktionen von Bedeutung sind, sondern dass auch die Variationsbreite der Verhaltensunterschiede innerhalb der Arten eine entscheidende Rolle spielt. Zusammenfassend verdeutlicht die vorliegende Arbeit wie wichtig die Berücksichtigung von stabilen individuellen Verhaltensunterschieden im Hinblick auf räumliche Parameter ist. Darüber hinaus zeigen die vorliegenden Ergebnisse, dass individuelle Verhaltensunterschiede für die Besetzung individueller Nischen und damit für inner- und zwischenartlichen Interaktionen von großer Bedeutung sind. Innerhalb dieser Arbeit werden individuelle Verhaltensunterschiede in Zusammenhang mit der Ähnlichkeit von Arten, der Breite von individuellen Nischen und Artnischen, sowie deren Überlappung gebracht. Diese Arbeit stellt somit eine Erweiterung des bisherigen Forschungstandes hinsichtlich der Einbeziehung von individuellen Verhaltensunterschieden in die Theorie der Koexistenz von Arten dar. KW - ecological interactions KW - inter-individual differences KW - animal personality KW - movement ecology KW - space use Y1 - 2019 ER - TY - GEN A1 - Schieferdecker, Anne A1 - Wendler, Petra T1 - Structural mapping of missense mutations in the Pex1/Pex6 complex T2 - Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe N2 - Peroxisome biogenesis disorders (PBDs) are nontreatable hereditary diseases with a broad range of severity. Approximately 65% of patients are affected by mutations in the peroxins Pex1 and Pex6. The proteins form the heteromeric Pex1/Pex6 complex, which is important for protein import into peroxisomes. To date, no structural data are available for this AAA+ ATPase complex. However, a wealth of information can be transferred from low-resolution structures of the yeast scPex1/scPex6 complex and homologous, well-characterized AAA+ ATPases. We review the abundant records of missense mutations described in PBD patients with the aim to classify and rationalize them by mapping them onto a homology model of the human Pex1/Pex6 complex. Several mutations concern functionally conserved residues that are implied in ATP hydrolysis and substrate processing. Contrary to fold destabilizing mutations, patients suffering from function-impairing mutations may not benefit from stabilizing agents, which have been reported as potential therapeutics for PBD patients. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 1072 KW - Zellweger syndrome spectrum disorder (ZSSD) KW - Zellweger KW - structure KW - Pex1 KW - Pex6 KW - mutation Y1 - 2021 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-472843 SN - 1866-8372 IS - 1072 ER - TY - JOUR A1 - Schieferdecker, Anne A1 - Wendler, Petra T1 - Structural Mapping of Missense Mutations in the Pex1/Pex6 Complex JF - International journal of molecular sciences N2 - Peroxisome biogenesis disorders (PBDs) are nontreatable hereditary diseases with a broad range of severity. Approximately 65% of patients are affected by mutations in the peroxins Pex1 and Pex6. The proteins form the heteromeric Pex1/Pex6 complex, which is important for protein import into peroxisomes. To date, no structural data are available for this AAA+ ATPase complex. However, a wealth of information can be transferred from low-resolution structures of the yeast scPex1/scPex6 complex and homologous, well-characterized AAA+ ATPases. We review the abundant records of missense mutations described in PBD patients with the aim to classify and rationalize them by mapping them onto a homology model of the human Pex1/Pex6 complex. Several mutations concern functionally conserved residues that are implied in ATP hydrolysis and substrate processing. Contrary to fold destabilizing mutations, patients suffering from function-impairing mutations may not benefit from stabilizing agents, which have been reported as potential therapeutics for PBD patients. KW - Zellweger syndrome spectrum disorder (ZSSD) KW - Zellweger KW - structure KW - Pex1 KW - Pex6 KW - mutation Y1 - 2019 U6 - https://doi.org/10.3390/ijms20153756 SN - 1422-0067 VL - 20 IS - 15 PB - MDPI CY - Basel ER - TY - THES A1 - Scherer, Philipp Cédric T1 - Infection on the move T1 - Infektion in Bewegung BT - individual host movement drives disease persistence in spatially structured landscapes BT - individuelle Der Einfluss von Bewegung von Wirtstieren auf die Persistenz von Krankheiten in räumlich strukturierten Landschaften N2 - Movement plays a major role in shaping population densities and contact rates among individuals, two factors that are particularly relevant for disease outbreaks. Although any differences in movement behaviour due to individual characteristics of the host and heterogeneity in landscape structure are likely to have considerable consequences for disease dynamics, these mechanisms are neglected in most epidemiological studies. Therefore, developing a general understanding how the interaction of movement behaviour and spatial heterogeneity shapes host densities, contact rates and ultimately pathogen spread is a key question in ecological and epidemiological research. In my thesis, I address this gap using both theoretical and empirical modelling approaches. In the theoretical part of my thesis, I investigated bottom-up effects of individual movement behaviour and landscape structure on host density, contact rates, and ultimately disease dynamics. I extended an established agent-based model that simulates ecological and epidemiological key processes to incorporate explicit movement of host individuals and landscape complexity. Neutral landscape models are a powerful basis for spatially-explicit modelling studies to imitate the complex characteristics of natural landscapes. In chapter 2, the first study of my thesis, I introduce two complementary R packages, NLMR and landscapetools, that I have co-developed to simplify the workflow of simulation and customization of such landscapes. To demonstrate the use of the packages I present a case study using the spatially explicit eco-epidemiological model and show that landscape complexity per se increases the probability of disease persistence. By using simple rules to simulate explicit host movement, I highlight in chapter 3 how disease dynamics are affected by population-level properties emerging from different movement rules leading to differences in the realized movement distance, spatiotemporal host density, and heterogeneity in transmission rates. As a consequence, mechanistic movement decisions based on the underlying landscape or conspecific competition led to considerably higher probabilities than phenomenological random walk approaches due directed movement leading to spatiotemporal differences in host densities. The results of these two chapters highlight the need to explicitly consider spatial heterogeneity and host movement behaviour when theoretical approaches are used to assess control measures to prevent outbreaks or eradicate diseases. In the empirical part of my thesis (chapter 4), I focus on the spatiotemporal dynamics of Classical Swine Fever in a wild boar population by analysing epidemiological data that was collected during an outbreak in Northern Germany persisting for eight years. I show that infection risk exhibits different seasonal patterns on the individual and the regional level. These patterns on the one hand show a higher infection risk in autumn and winter that may arise due to onset of mating behaviour and hunting intensity, which result in increased movement ranges. On the other hand, the increased infection risk of piglets, especially during the birth season, indicates the importance of new susceptible host individuals for local pathogen spread. The findings of this chapter underline the importance of different spatial and temporal scales to understand different components of pathogen spread that can have important implications for disease management. Taken together, the complementary use of theoretical and empirical modelling in my thesis highlights that our inferences about disease dynamics depend heavily on the spatial and temporal resolution used and how the inclusion of explicit mechanisms underlying hosts movement are modelled. My findings are an important step towards the incorporation of spatial heterogeneity and a mechanism-based perspective in eco-epidemiological approaches. This will ultimately lead to an enhanced understanding of the feedbacks of contact rates on pathogen spread and disease persistence that are of paramount importance to improve predictive models at the interface of ecology and epidemiology. N2 - Bewegung nimmt eine zentrale Rolle bei der Entstehung von Populationsdichten und Kontaktraten zwischen Individuen ein, zwei Faktoren, die bei einem Krankheitsausbruch von besonderer Bedeutung sind. Obwohl Unterschiede im Bewegungsverhalten aufgrund individueller Merkmale des Wirtes und der Heterogenität der Landschaftsstruktur erhebliche Auswirkungen auf Krankheitsdynamiken haben, werden diese Mechanismen in den meisten epidemiologischen Studien vernachlässigt. Daher ist die Frage, wie das Zusammenspiel von Bewegungsverhalten mit räumlicher Heterogenität die Wirtsdichte und die Kontaktraten und somit letztlich die Ausbreitung von Krankheitserregern beeinflusst, eine Schlüsselfrage in der ökologisch-epidemiologischen Forschung. In meiner Dissertation gehe ich diese Frage mit theoretischen und empirischen Modellierungs-ansätzen an. Im theoretischen Teil meiner Arbeit untersuchte ich die Effekte des individuellen Bewegungsverhaltens und der Landschaftsstruktur auf die Wirtsdichte, die Kontaktraten und letztendlich auf Krankheitsdynamiken. Dafür habe ich ein etabliertes agentenbasiertes Modell angepasst, das ökologische und epidemiologische Prozesse simuliert, um die genaue Bewegung von Wirtsindividuen und die Komplexität der Landschaft zu berücksichtigen. Dabei sind sogenannte „Neutrale Landschaftsmodelle“ eine objektive Grundlage, um die komplexen Eigenschaften von natürlichen Landschaften nachzuahmen. In Kapitel 2, der ersten Studie in meiner Dissertation, stelle ich zwei komplementäre Erweiterungen für die Programmiersprache R vor, NLMR und landscapetools, die ich entscheidend mitentwickelt habe, um die Simulation und Modifizierung solcher Landschaften zu vereinfachen. Um die Verwendung dieser Erweiterungen zu demonstrieren, stelle ich eine Fallstudie basierend auf dem ökologisch-epidemiologischen Simulationsmodell vor und zeige, dass heterogene Landschaften per se die Wahrscheinlichkeit der Persistenz von Krankheiten erhöhen. Im dritten Kapitel zeige ich, wie großskalige Dynamiken während eines Krankheitsausbruchs durch verschiedene Bewegungsregeln der Wirtstiere beeinflusst werden. Diese verschiedenen Bewegungsregeln hatten dabei Bewegungs- und Kontaktmuster mit Unterschieden in der realisierten Bewegungsdistanz, der raumzeitlichen Verteilung von Wirtstieren, sowie der Übertragungsraten zwischen den Habitaten zur Folge. Infolgedessen führten mechanistische Bewegungsentscheidungen, die auf Eigenschaften der Landschaft oder der Intensität der Konkurrenz beruhten, zu deutlich höheren Wahrscheinlichkeiten als phänomenologische Zufallslauf („random walk“)-Ansätze. Die Ergebnisse dieser beiden Kapitel verdeutlichen die Notwendigkeit, die räumliche Heterogenität und das Bewegungsverhalten der Wirte explizit zu berücksichtigen, wenn solche theoretischen Modelle in der Praxis Anwendung finden sollen, z. B. um Strategien zur Eindämmung von Seuchenzügen in Wildtieren zu entwickeln. Im empirischen Teil meiner Arbeit (Kapitel 4) konzentriere ich mich auf die raumzeitliche Dynamik eines Ausbruchs der Klassischen Schweinepest in einer Wildschweinpopulation mittels Analyse epidemiologischer Daten, die während eines Ausbruchs in Norddeutschland über acht Jahre aufgenommen wurden. Das Infektionsrisiko auf individueller und regionaler Ebene wies dabei unterschiedliche saisonale Muster auf. Diese Muster zeigen einerseits ein erhöhtes regionales Infektionsrisiko im Herbst und Winter, das womöglich aufgrund erhöhter Bewegungsraten der Wirtstiere auftritt, und durch das Paarungsverhalten und der Jagdintensität während dieser Zeitausgelöst wird. Andererseits unterstreicht das erhöhte individuelle Infektionsrisiko von Frisch-lingen, insbesondere während der Geburtszeit, die Auswirkungen von lokal erhöhten Wirtsdichten auf die lokale Ausbreitung von Krankheitserregern. Die Ergebnisse dieses Kapitels zeigen die Bedeutung verschiedener räumlicher und zeitlicher Skalen für das Verständnis verschiedener Komponenten von Epidemien, die wichtige Auswirkungen auf das Krankheitsmanagement haben können. Zusammenfassend unterstreicht der komplementäre Einsatz theoretischer und empirischer Modellierung in meiner Arbeit, dass es unerlässlich ist, die mechanistische Basis der Wirts-Kontakt-raten zu berücksichtigen, nämlich räumliche Heterogenität und Bewegungsverhalten der Wirtstiere, um ein Verständnis über Krankheitsverläufe in Wildtierbeständen zu erlangen und Schluss-folgerungen über das Persistenzgeschehen ziehen zu können. Meine Ergebnisse sind ein erster wichtiger Schritt in diese Richtung. KW - movement ecology KW - disease ecology KW - landscape heterogeneity KW - Rstats KW - agent-based model KW - disease persistence KW - wild boar KW - classical swine fever KW - Bewegungsökologie KW - Krankheitsökologie KW - Landschaftsheterogenität KW - R (Programmiersprache) KW - agentenbasiertes Modell KW - Krankheitsausbruch KW - Wildschwein KW - klassische Schweinepest Y1 - 2019 ER - TY - JOUR A1 - Scherer, Cedric A1 - Radchuk, Viktoriia A1 - Staubach, Christoph A1 - Mueller, Sophie A1 - Blaum, Niels A1 - Thulke, Hans-Hermann A1 - Kramer-Schadt, Stephanie T1 - Seasonal host life-history processes fuel disease dynamics at different spatial scales JF - Journal of animal ecology : a journal of the British Ecological Society N2 - Understanding the drivers underlying disease dynamics is still a major challenge in disease ecology, especially in the case of long-term disease persistence. Even though there is a strong consensus that density-dependent factors play an important role for the spread of diseases, the main drivers are still discussed and, more importantly, might differ between invasion and persistence periods. Here, we analysed long-term outbreak data of classical swine fever, an important disease in both wild boar and livestock, prevalent in the wild boar population from 1993 to 2000 in Mecklenburg-Vorpommern, Germany. We report outbreak characteristics and results from generalized linear mixed models to reveal what factors affected infection risk on both the landscape and the individual level. Spatiotemporal outbreak dynamics showed an initial wave-like spread with high incidence during the invasion period followed by a drop of incidence and an increase in seroprevalence during the persistence period. Velocity of spread increased with time during the first year of outbreak and decreased linearly afterwards, being on average 7.6 km per quarter. Landscape- and individual-level analyses of infection risk indicate contrasting seasonal patterns. During the persistence period, infection risk on the landscape level was highest during autumn and winter seasons, probably related to spatial behaviour such as increased long-distance movements and contacts induced by rutting and escaping movements. In contrast, individual-level infection risk peaked in spring, probably related to the concurrent birth season leading to higher densities, and was significantly higher in piglets than in reproductive animals. Our findings highlight that it is important to investigate both individual- and landscape-level patterns of infection risk to understand long-term persistence of wildlife diseases and to guide respective management actions. Furthermore, we highlight that exploring different temporal aggregation of the data helps to reveal important seasonal patterns, which might be masked otherwise. KW - classical swine fever KW - disease invasion KW - infection risk KW - pathogen persistence KW - seasonality KW - Sus scrofa KW - wild boar KW - wildlife disease Y1 - 2019 U6 - https://doi.org/10.1111/1365-2656.13070 SN - 0021-8790 SN - 1365-2656 VL - 88 IS - 11 SP - 1812 EP - 1824 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Scheller, Frieder W. A1 - Zhang, Xiaorong A1 - Yarman, Aysu A1 - Wollenberger, Ulla A1 - Gyurcsányi, Róbert E. T1 - Molecularly imprinted polymer-based electrochemical sensors for biopolymers JF - Current opinion in electrochemistry N2 - Electrochemical synthesis and signal generation dominate among the almost 1200 articles published annually on protein-imprinted polymers. Such polymers can be easily prepared directly on the electrode surface, and the polymer thickness can be precisely adjusted to the size of the target to enable its free exchange. In this architecture, the molecularly imprinted polymer (MIP) layer represents only one ‘separation plate’; thus, the selectivity does not reach the values of ‘bulk’ measurements. The binding of target proteins can be detected straightforwardly by their modulating effect on the diffusional permeability of a redox marker through the thin MIP films. However, this generates an ‘overall apparent’ signal, which may include nonspecific interactions in the polymer layer and at the electrode surface. Certain targets, such as enzymes or redox active proteins, enables a more specific direct quantification of their binding to MIPs by in situ determination of the enzyme activity or direct electron transfer, respectively. KW - Electropolymerization KW - Direct electron transfer KW - Redox marker KW - Epitope imprinting KW - Biomarker Y1 - 2018 U6 - https://doi.org/10.1016/j.coelec.2018.12.005 SN - 2451-9103 VL - 14 SP - 53 EP - 59 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Sauer, Michael A1 - Kleine-Vehn, Jürgen T1 - PIN-FORMED and PIN-LIKES auxin transport facilitators JF - Development : Company of Biologists N2 - The phytohormone auxin influences virtually all aspects of plant growth and development. Auxin transport across membranes is facilitated by, among other proteins, members of the PIN-FORMED (PIN) and the structurally similar PIN-LIKES (PILS) families, which together govern directional cell-to-cell transport and intracellular accumulation of auxin. Canonical PIN proteins, which exhibit a polar localization in the plasma membrane, determine many patterning and directional growth responses. Conversely, the less-studied noncanonical PINs and PILS proteins, which mostly localize to the endoplasmic reticulum, attenuate cellular auxin responses. Here, and in the accompanying poster, we provide a brief summary of current knowledge of the structure, evolution, function and regulation of these auxin transport facilitators. KW - Auxin KW - Auxin transport KW - Phytohormone Y1 - 2019 U6 - https://doi.org/10.1242/dev.168088 SN - 0950-1991 SN - 1477-9129 VL - 146 IS - 15 PB - Company biologists ltd CY - Cambridge ER - TY - JOUR A1 - Rühl, Martin A1 - Pietzner, Verena A1 - Vilcinskas, Andreas A1 - Zorn, Holger T1 - Insects and molds as bio-resources: food biotechnology JF - Chemie in unserer Zeit N2 - Microorganisms are used for the production of foodstuffs since thousands of years. By now, these biotechnological processes are not restricted to some of the known microorganisms. The possibility to produce enzymes independently from their host organisms extended their range of application. Since then, exploration of new bioresources leads to novel enzymes and peptides applicable for a diverse set of food production processes: peptidases of grain pest beetles are able to hydrolyse gluten and antimicrobial active peptides of insects maybe of use for preservation of food. Examples of our own work depict strategies to identify novel biocatalysts for food biotechnology. N2 - Mikroorganismen werden seit Jahrtausenden zur Herstellung von Lebensmitteln genutzt. Mittlerweile sind diese biotechnologischen Verfahren nicht mehr auf die Verwendung einiger Organismen beschränkt. Die Möglichkeit, Enzyme unabhängig von ihrem Wirtsorganismus zu produzieren, erweiterte den Einsatzbereich dieser technischen Hilfsmittel ungemein. Seither werden vermehrt neue Bioressourcen erschlossen, um neuartige Enzyme und Peptide für die Lebensmittelproduktion verfügbar zu machen: Peptidasen aus Getreideschädlingen vermögen Gluten zu hydrolysieren und antimikrobiell wirksame Peptide aus Insekten könnten zur Haltbarmachung von Lebensmitteln eingesetzt werden. Aber wie findet man solche Katalysatoren? Beispiele aus eigenen Arbeiten zeigen es. T2 - Insekten und Schimmelpilze als Bioressource KW - Gelbe Biotechnologie KW - Insekten KW - Ascomyceten KW - antimikrobielle Peptide Y1 - 2019 U6 - https://doi.org/10.1002/ciuz.201900833 SN - 0009-2851 SN - 1521-3781 VL - 53 IS - 5 SP - 342 EP - 348 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Rödel, Claudia Jasmin A1 - Otten, Cecile A1 - Donat, Stefan A1 - Lourenço, Marta Sofia Rocha A1 - Fischer, Dorothea A1 - Kuropka, Benno A1 - Paolini, Alessio A1 - Freund, Christian A1 - Abdelilah-Seyfried, Salim T1 - Blood Flow Suppresses Vascular Anomalies in a Zebrafish Model of Cerebral Cavernous Malformations JF - Circulation Research N2 - RATIONALE: Pathological biomechanical signaling induces vascular anomalies including cerebral cavernous malformations (CCM), which are caused by a clonal loss of CCM1/KRIT1 (Krev interaction trapped protein 1), CCM2/MGC4607, or CCM3/PDCD10. Why patients typically experience lesions only in lowly perfused venous capillaries of the cerebrovasculature is completely unknown. OBJECTIVE: In contrast, animal models with a complete loss of CCM proteins lack a functional heart and blood flow and exhibit vascular anomalies within major blood vessels as well. This finding raises the possibility that hemodynamics may play a role in the context of this vascular pathology. METHODS AND RESULTS: Here, we used a genetic approach to restore cardiac function and blood flow in a zebrafish model of CCM1. We find that blood flow prevents cardiovascular anomalies including a hyperplastic expansion within a large Ccm1-deficient vascular bed, the lateral dorsal aorta. CONCLUSIONS: This study identifies blood flow as an important physiological factor that is protective in the cause of this devastating vascular pathology. KW - animal models KW - cerebral cavernous malformations KW - endothelial cell KW - hemodynamics KW - zebrafish Y1 - 2019 U6 - https://doi.org/10.1161/CIRCRESAHA.119.315076 SN - 0009-7330 SN - 1524-4571 VL - 125 IS - 10 SP - E43 EP - E54 PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - JOUR A1 - Ryser, Remo A1 - Häussler, Johanna A1 - Stark, Markus A1 - Brose, Ulrich A1 - Rall, Björn C. A1 - Guill, Christian T1 - The biggest losers: habitat isolation deconsructs complex food webs from top to bottom JF - Proceedings of the Royal Society of London : B, Biological sciences N2 - Habitat fragmentation threatens global biodiversity. To date, there is only limited understanding of how the different aspects of habitat fragmentation (habitat loss, number of fragments and isolation) affect species diversity within complex ecological networks such as food webs. Here, we present a dynamic and spatially explicit food web model which integrates complex food web dynamics at the local scale and species-specific dispersal dynamics at the landscape scale, allowing us to study the interplay of local and spatial processes in metacommunities. We here explore how the number of habitat patches, i.e. the number of fragments, and an increase of habitat isolation affect the species diversity patterns of complex food webs (alpha-,beta-,gamma-, diversities). We specifically test whether there is a trophic dependency in the effect of these two factors on species diversity. In our model, habitat isolation is the main driver causing species loss and diversity decline. Our results emphasize that large-bodied consumer species at high trophic positions go extinct faster than smaller species at lower trophic levels, despite being superior dispersers that connect fragmented landscapes better. We attribute the loss of top species to a combined effect of higher biomass loss during dispersal with increasing habitat isolation in general, and the associated energy limitation in highly fragmented landscapes, preventing higher trophic levels to persist. To maintain trophic-complex and species-rich communities calls for effective conservation planning which considers the interdependence of trophic and spatial dynamics as well as the spatial context of a landscape and its energy availability. KW - food webs KW - allometry KW - bioenergetic model KW - metacommunity dynamics KW - dispersal mortality KW - landscape structure Y1 - 2019 U6 - https://doi.org/10.1098/rspb.2019.1177 SN - 0962-8452 SN - 1471-2954 VL - 286 IS - 1908 PB - Royal Society CY - London ER - TY - JOUR A1 - Rossberg, Axel G. A1 - Gaedke, Ursula A1 - Kratina, Pavel T1 - Dome patterns in pelagic size spectra reveal strong trophic cascades JF - Nature Communications N2 - In ecological communities, especially the pelagic zones of aquatic ecosystems, certain bodysize ranges are often over-represented compared to others. Community size spectra, the distributions of community biomass over the logarithmic body-mass axis, tend to exhibit regularly spaced local maxima, called "domes", separated by steep troughs. Contrasting established theory, we explain these dome patterns as manifestations of top-down trophic cascades along aquatic food chains. Compiling high quality size-spectrum data and comparing these with a size-spectrum model introduced in this study, we test this theory and develop a detailed picture of the mechanisms by which bottom-up and top-down effects interact to generate dome patterns. Results imply that strong top-down trophic cascades are common in freshwater communities, much more than hitherto demonstrated, and may arise in nutrient rich marine systems as well. Transferring insights from the general theory of nonlinear pattern formation to domes patterns, we provide new interpretations of past lake-manipulation experiments. Y1 - 2019 U6 - https://doi.org/10.1038/s41467-019-12289-0 SN - 2041-1723 VL - 10 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Rosenbaum, Benjamin A1 - Raatz, Michael A1 - Weithoff, Guntram A1 - Fussmann, Gregor F. A1 - Gaedke, Ursula T1 - Estimating parameters from multiple time series of population dynamics using bayesian inference JF - Frontiers in ecology and evolution N2 - Empirical time series of interacting entities, e.g., species abundances, are highly useful to study ecological mechanisms. Mathematical models are valuable tools to further elucidate those mechanisms and underlying processes. However, obtaining an agreement between model predictions and experimental observations remains a demanding task. As models always abstract from reality one parameter often summarizes several properties. Parameter measurements are performed in additional experiments independent of the ones delivering the time series. Transferring these parameter values to different settings may result in incorrect parametrizations. On top of that, the properties of organisms and thus the respective parameter values may vary considerably. These issues limit the use of a priori model parametrizations. In this study, we present a method suited for a direct estimation of model parameters and their variability from experimental time series data. We combine numerical simulations of a continuous-time dynamical population model with Bayesian inference, using a hierarchical framework that allows for variability of individual parameters. The method is applied to a comprehensive set of time series from a laboratory predator-prey system that features both steady states and cyclic population dynamics. Our model predictions are able to reproduce both steady states and cyclic dynamics of the data. Additionally to the direct estimates of the parameter values, the Bayesian approach also provides their uncertainties. We found that fitting cyclic population dynamics, which contain more information on the process rates than steady states, yields more precise parameter estimates. We detected significant variability among parameters of different time series and identified the variation in the maximum growth rate of the prey as a source for the transition from steady states to cyclic dynamics. By lending more flexibility to the model, our approach facilitates parametrizations and shows more easily which patterns in time series can be explained also by simple models. Applying Bayesian inference and dynamical population models in conjunction may help to quantify the profound variability in organismal properties in nature. KW - Bayesian inference KW - chemostat experiments KW - ordinary differential equation KW - parameter estimation KW - population dynamics KW - predator prey KW - time series analysis KW - trait variability Y1 - 2019 U6 - https://doi.org/10.3389/fevo.2018.00234 SN - 2296-701X VL - 6 PB - Frontiers Research Foundation CY - Lausanne ER - TY - JOUR A1 - Romero-Mujalli, Daniel A1 - Jeltsch, Florian A1 - Tiedemann, Ralph T1 - Elevated mutation rates are unlikely to evolve in sexual species, not even under rapid environmental change JF - BMC Evolutionary Biology N2 - Background Organisms are expected to respond to changing environmental conditions through local adaptation, range shift or local extinction. The process of local adaptation can occur by genetic changes or phenotypic plasticity, and becomes especially relevant when dispersal abilities or possibilities are somehow constrained. For genetic changes to occur, mutations are the ultimate source of variation and the mutation rate in terms of a mutator locus can be subject to evolutionary change. Recent findings suggest that the evolution of the mutation rate in a sexual species can advance invasion speed and promote adaptation to novel environmental conditions. Following this idea, this work uses an individual-based model approach to investigate if the mutation rate can also evolve in a sexual species experiencing different conditions of directional climate change, under different scenarios of colored stochastic environmental noise, probability of recombination and of beneficial mutations. The color of the noise mimicked investigating the evolutionary dynamics of the mutation rate in different habitats. Results The results suggest that the mutation rate in a sexual species experiencing directional climate change scenarios can evolve and reach relatively high values mainly under conditions of complete linkage of the mutator locus and the adaptation locus. In contrast, when they are unlinked, the mutation rate can slightly increase only under scenarios where at least 50% of arising mutations are beneficial and the rate of environmental change is relatively fast. This result is robust under different scenarios of stochastic environmental noise, which supports the observation of no systematic variation in the mutation rate among organisms experiencing different habitats. Conclusions Given that 50% beneficial mutations may be an unrealistic assumption, and that recombination is ubiquitous in sexual species, the evolution of an elevated mutation rate in a sexual species experiencing directional climate change might be rather unlikely. Furthermore, when the percentage of beneficial mutations and the population size are small, sexual species (especially multicellular ones) producing few offspring may be expected to react to changing environments not by adaptive genetic change, but mainly through plasticity. Without the ability for a plastic response, such species may become – at least locally – extinct. KW - Individual-based models KW - sexual species KW - Beneficial mutations KW - Recombination KW - Directional climate change KW - Mutator locus KW - Mutation rate Y1 - 2019 U6 - https://doi.org/10.1186/s12862-019-1494-0 SN - 1471-2148 VL - 19 PB - BioMed Central CY - London ER - TY - GEN A1 - Romero-Mujalli, Daniel A1 - Jeltsch, Florian A1 - Tiedemann, Ralph T1 - Elevated mutation rates are unlikely to evolve in sexual species, not even under rapid environmental change T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe N2 - Background Organisms are expected to respond to changing environmental conditions through local adaptation, range shift or local extinction. The process of local adaptation can occur by genetic changes or phenotypic plasticity, and becomes especially relevant when dispersal abilities or possibilities are somehow constrained. For genetic changes to occur, mutations are the ultimate source of variation and the mutation rate in terms of a mutator locus can be subject to evolutionary change. Recent findings suggest that the evolution of the mutation rate in a sexual species can advance invasion speed and promote adaptation to novel environmental conditions. Following this idea, this work uses an individual-based model approach to investigate if the mutation rate can also evolve in a sexual species experiencing different conditions of directional climate change, under different scenarios of colored stochastic environmental noise, probability of recombination and of beneficial mutations. The color of the noise mimicked investigating the evolutionary dynamics of the mutation rate in different habitats. Results The results suggest that the mutation rate in a sexual species experiencing directional climate change scenarios can evolve and reach relatively high values mainly under conditions of complete linkage of the mutator locus and the adaptation locus. In contrast, when they are unlinked, the mutation rate can slightly increase only under scenarios where at least 50% of arising mutations are beneficial and the rate of environmental change is relatively fast. This result is robust under different scenarios of stochastic environmental noise, which supports the observation of no systematic variation in the mutation rate among organisms experiencing different habitats. Conclusions Given that 50% beneficial mutations may be an unrealistic assumption, and that recombination is ubiquitous in sexual species, the evolution of an elevated mutation rate in a sexual species experiencing directional climate change might be rather unlikely. Furthermore, when the percentage of beneficial mutations and the population size are small, sexual species (especially multicellular ones) producing few offspring may be expected to react to changing environments not by adaptive genetic change, but mainly through plasticity. Without the ability for a plastic response, such species may become – at least locally – extinct. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 776 KW - Individual-based models KW - sexual species KW - Beneficial mutations KW - Mutation rate KW - Mutator locus KW - Directional climate change KW - Recombination Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-439058 SN - 1866-8372 IS - 776 ER - TY - THES A1 - Romero Mujalli, Daniel T1 - Ecological modeling of adaptive evolutionary responses to rapid climate change T1 - Ökologische Modellierung anpassungsfähiger evolutionärer Reaktionen auf schnellen Klimawandel N2 - A contemporary challenge in Ecology and Evolutionary Biology is to anticipate the fate of populations of organisms in the context of a changing world. Climate change and landscape changes due to anthropic activities have been of major concern in the contemporary history. Organisms facing these threats are expected to respond by local adaptation (i.e., genetic changes or phenotypic plasticity) or by shifting their distributional range (migration). However, there are limits to their responses. For example, isolated populations will have more difficulties in developing adaptive innovations by means of genetic changes than interconnected metapopulations. Similarly, the topography of the environment can limit dispersal opportunities for crawling organisms as compared to those that rely on wind. Thus, populations of species with different life history strategy may differ in their ability to cope with changing environmental conditions. However, depending on the taxon, empirical studies investigating organisms’ responses to environmental change may become too complex, long and expensive; plus, complications arising from dealing with endangered species. In consequence, eco-evolutionary modeling offers an opportunity to overcome these limitations and complement empirical studies, understand the action and limitations of underlying mechanisms, and project into possible future scenarios. In this work I take a modeling approach and investigate the effect and relative importance of evolutionary mechanisms (including phenotypic plasticity) on the ability for local adaptation of populations with different life strategy experiencing climate change scenarios. For this, I performed a review on the state of the art of eco-evolutionary Individual-Based Models (IBMs) and identify gaps for future research. Then, I used the results from the review to develop an eco-evolutionary individual-based modeling tool to study the role of genetic and plastic mechanisms in promoting local adaption of populations of organisms with different life strategies experiencing scenarios of climate change and environmental stochasticity. The environment was simulated through a climate variable (e.g., temperature) defining a phenotypic optimum moving at a given rate of change. The rate of change was changed to simulate different scenarios of climate change (no change, slow, medium, rapid climate change). Several scenarios of stochastic noise color resembling different climatic conditions were explored. Results show that populations of sexual species will rely mainly on standing genetic variation and phenotypic plasticity for local adaptation. Population of species with relatively slow growth rate (e.g., large mammals) – especially those of small size – are the most vulnerable, particularly if their plasticity is limited (i.e., specialist species). In addition, whenever organisms from these populations are capable of adaptive plasticity, they can buffer fitness losses in reddish climatic conditions. Likewise, whenever they can adjust their plastic response (e.g., bed-hedging strategy) they will cope with bluish environmental conditions as well. In contrast, life strategies of high fecundity can rely on non-adaptive plasticity for their local adaptation to novel environmental conditions, unless the rate of change is too rapid. A recommended management measure is to guarantee interconnection of isolated populations into metapopulations, such that the supply of useful genetic variation can be increased, and, at the same time, provide them with movement opportunities to follow their preferred niche, when local adaptation becomes problematic. This is particularly important for bluish and reddish climatic conditions, when the rate of change is slow, or for any climatic condition when the level of stress (rate of change) is relatively high. N2 - Eine aktuelle Herausforderung in der Ökologie und Evolutionsbiologie besteht darin, das Schicksal von Populationen verschiedener Lebewesen im Kontext einer sich verändernden Welt zu antizipieren. Der Klimawandel und die durch anthropologische Aktivitäten verursachten Landschaftsveränderungen sind im Laufe der Geschichte von großer Bedeutung geworden. Von den Organismen, die sich diesen Veränderungen stellen, wird erwartet, dass sie durch lokale Anpassung (d.h. genetische Veränderungen oder phänotypische Plastizität) oder durch Verschiebung ihres Verbreitungsgebietes (Migration) darauf reagieren. Allerdings sind diese Reaktionen begrenzt. So werden beispielsweise isolierte Populationen mehr Schwierigkeiten bei der Entwicklung adaptiver Neuheiten mittels genetischer Variation haben als vernetzte Metapopulationen. Ebenso kann die Topographie der Umgebung die Ausbreitungsmöglichkeiten für zum Beispiel kriechende Organismen im Vergleich zu denen, die auf Wind angewiesen sind, einschränken. So können Populationen von Arten mit unterschiedlichen Lebensstrategien verschiedene Fähigkeiten haben, mit den sich ändernden Umweltbedingungen umzugehen. Empirische Studien, die die Reaktionen von Organismen auf Umweltveränderungen untersuchen, können jedoch, je nach Taxon, zu komplex, langwierig und teuer werden. Ebenso sollten Komplikationen im Umgang mit gefährdeten Arten nicht außer Acht gelassen werden. Die ökoevolutionäre Modellierung bietet jedoch die Möglichkeit, diese Einschränkungen zu überwinden und empirische Studien zu ergänzen, die Wirkung und Grenzen der zugrunde liegenden Mechanismen zu verstehen und mögliche Zukunftsszenarien zu erstellen. In dieser Arbeit untersuche ich mittels einer Modellierungsmethode die Wirkung und relative Bedeutung evolutionärer Mechanismen (einschließlich phänotypischer Plastizität) auf die Fähigkeit zur lokalen Anpassung von Populationen mit unterschiedlichen Lebensstrategien, die Szenarien des Klimawandels durchleben. Dazu habe ich in einem Review den Stand der Technik ökoevolutionärer individuenbasierender Modelle (Individual-Based Models; IBMs) zusammengefasst und Ansätze für eine zukünftige Forschung identifiziert. Die Erkenntnisse des Reviews nutzte ich, um ein ökoevolutionäres, individuelles Modellierungsprogramm zu entwickeln. Dieses analysiert die Rolle genetischer und plastischer Mechanismen zur Förderung der lokalen Anpassung organismischer Populationen mit unterschiedlichen Lebensstrategien, welche Szenarien des Klimawandels und der ökologischen Stochastik erfahren. Die Umweltbedingungen wurden durch eine klimatische Variable (z.B. Temperatur) simuliert, die ein phänotypisches Optimum definiert, das sich mit einer bestimmten Änderungsrate bewegt. Verschiedene Änderungsraten wurden angewandt, um unterschiedliche Szenarien des Klimawandels darzustellen (keine Veränderung, langsamer, mittlerer, schneller Klimawandel). Es wurden mehrere Szenarien stochastischen Farbrauschens untersucht, die verschiedene klimatische Bedingungen widerspiegeln. Die Ergebnisse zeigen, dass Populationen sexueller Arten hauptsächlich auf genetische Variation und phänotypische Plastizität hinsichtlich lokalen Anpassung angewiesen sind. Populationen von Arten mit relativ langsamer Wachstumsrate (z.B. große Säugetiere), und insbesondere die mit kleiner Populationsgröße, sind am anfälligsten, vor allem wenn ihre Plastizität begrenzt ist (d.h. spezialisierte Arten). Wenn Individuen dieser Populationen zu adaptiver Plastizität fähig sind, können sie Fitnessverluste unter „rötlichen“ Klimabedingungen ausgleichen. Zugleich können diese Populationen durch Anpassung der Plastizität auch unter bläulichen Umweltbedingungen zurecht kommen (z.B. Bed-Hedging-Strategie). Im Gegensatz dazu können sich Lebensstrategen mit hoher Reproduktionszahl auf nicht-adaptive Plastizität zur lokalen Anpassung an neue Umweltbedingungen verlassen, es sei denn, die Änderungsrate ist zu schnell. Eine empfohlene Handlungsmaßnahme ist es, die Eingliederung von isolierten Populationen in Metapopulationen zu gewährleisten, so dass die genetische Variation erhöht werden kann. Wenn eine lokale Anpassung problematisch wird, sollte ihnen gleichzeitig Migrationsfreiraum gegeben werden, um ihrer bevorzugten Nische zu folgen. Dies ist besonders wichtig für „bläuliche“ und „rötliche“ Klimabedingungen, bei denen die Änderungsrate langsam ist, oder für jede klimatische Bedingung, wenn die Belastung (Änderungsrate) relativ hoch ist. KW - climate change KW - local adaptation KW - plasticity KW - evolution KW - individual-based model KW - Klimawandel KW - lokale Anpassung KW - Plastizität KW - Evolution KW - Individuen-basierende Modelle Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-430627 ER - TY - GEN A1 - Rojas-Jimenez, Keilor A1 - Rieck, Angelika A1 - Wurzbacher, Christian A1 - Jürgens, Klaus A1 - Labrenz, Matthias A1 - Grossart, Hans-Peter T1 - A Salinity Threshold Separating Fungal Communities in the Baltic Sea T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe N2 - Salinity is a significant factor for structuring microbial communities, but little is known for aquatic fungi, particularly in the pelagic zone of brackish ecosystems. In this study, we explored the diversity and composition of fungal communities following a progressive salinity decline (from 34 to 3 PSU) along three transects of ca. 2000 km in the Baltic Sea, the world’s largest estuary. Based on 18S rRNA gene sequence analysis, we detected clear changes in fungal community composition along the salinity gradient and found significant differences in composition of fungal communities established above and below a critical value of 8 PSU. At salinities below this threshold, fungal communities resembled those from freshwater environments, with a greater abundance of Chytridiomycota, particularly of the orders Rhizophydiales, Lobulomycetales, and Gromochytriales. At salinities above 8 PSU, communities were more similar to those from marine environments and, depending on the season, were dominated by a strain of the LKM11 group (Cryptomycota) or by members of Ascomycota and Basidiomycota. Our results highlight salinity as an important environmental driver also for pelagic fungi, and thus should be taken into account to better understand fungal diversity and ecological function in the aquatic realm. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 739 KW - fungal diversity KW - baltic sea KW - salinity gradient KW - brackish waters KW - chytridiomycota KW - cryptomycota Y1 - 1019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-434937 SN - 1866-8372 IS - 739 ER - TY - JOUR A1 - Rojas-Jimenez, Keilor A1 - Rieck, Angelika A1 - Wurzbacher, Christian A1 - Jürgens, Klaus A1 - Labrenz, Matthias A1 - Grossart, Hans-Peter T1 - A Salinity Threshold Separating Fungal Communities in the Baltic Sea JF - Frontiers in Microbiology N2 - Salinity is a significant factor for structuring microbial communities, but little is known for aquatic fungi, particularly in the pelagic zone of brackish ecosystems. In this study, we explored the diversity and composition of fungal communities following a progressive salinity decline (from 34 to 3 PSU) along three transects of ca. 2000 km in the Baltic Sea, the world’s largest estuary. Based on 18S rRNA gene sequence analysis, we detected clear changes in fungal community composition along the salinity gradient and found significant differences in composition of fungal communities established above and below a critical value of 8 PSU. At salinities below this threshold, fungal communities resembled those from freshwater environments, with a greater abundance of Chytridiomycota, particularly of the orders Rhizophydiales, Lobulomycetales, and Gromochytriales. At salinities above 8 PSU, communities were more similar to those from marine environments and, depending on the season, were dominated by a strain of the LKM11 group (Cryptomycota) or by members of Ascomycota and Basidiomycota. Our results highlight salinity as an important environmental driver also for pelagic fungi, and thus should be taken into account to better understand fungal diversity and ecological function in the aquatic realm. KW - fungal diversity KW - baltic sea KW - salinity gradient KW - brackish waters KW - chytridiomycota KW - cryptomycota Y1 - 2019 U6 - https://doi.org/10.3389/fmicb.2019.00680 SN - 1664-302X VL - 10 PB - Frontiers Media CY - Lausanne ER - TY - GEN A1 - Rodriguez-Sillke, Yasmina A1 - Steinhoff, U. A1 - Bojarski, Christian A1 - Lissner, Donata A1 - Schumann, Michael A1 - Branchi, F. A1 - Siegmund, Britta A1 - Glauben, Rainer T1 - Deep immune profiling of human Peyer´s Patches in patients of inflammatory bowel diseases T2 - European journal of immunology Y1 - 2019 U6 - https://doi.org/10.1002/eji.201970300 SN - 0014-2980 SN - 1521-4141 VL - 49 SP - 203 EP - 204 PB - Wiley CY - Weinheim ER - TY - GEN A1 - Riedel, Simona A1 - Siemiatkowska, Beata A1 - Watanabe, Mutsumi A1 - Müller, Christina S. A1 - Schünemann, Volker A1 - Hoefgen, Rainer A1 - Leimkühler, Silke T1 - The ABCB7-Like Transporter PexA in Rhodobacter capsulatus Is Involved in the Translocation of Reactive Sulfur Species T2 - Postprints der Universität Potsdam Mathematisch-Naturwissenschaftliche Reihe N2 - The mitochondrial ATP-binding cassette (ABC) transporters ABCB7 in humans, Atm1 in yeast and ATM3 in plants, are highly conserved in their overall architecture and particularly in their glutathione binding pocket located within the transmembrane spanning domains. These transporters have attracted interest in the last two decades based on their proposed role in connecting the mitochondrial iron sulfur (Fe–S) cluster assembly with its cytosolic Fe–S cluster assembly (CIA) counterpart. So far, the specific compound that is transported across the membrane remains unknown. In this report we characterized the ABCB7-like transporter Rcc02305 in Rhodobacter capsulatus, which shares 47% amino acid sequence identity with its mitochondrial counterpart. The constructed interposon mutant strain in R. capsulatus displayed increased levels of intracellular reactive oxygen species without a simultaneous accumulation of the cellular iron levels. The inhibition of endogenous glutathione biosynthesis resulted in an increase of total glutathione levels in the mutant strain. Bioinformatic analysis of the amino acid sequence motifs revealed a potential aminotransferase class-V pyridoxal-50-phosphate (PLP) binding site that overlaps with the Walker A motif within the nucleotide binding domains of the transporter. PLP is a well characterized cofactor of L-cysteine desulfurases like IscS and NFS1 which has a role in the formation of a protein-bound persulfide group within these proteins. We therefore suggest renaming the ABCB7-like transporter Rcc02305 in R. capsulatus to PexA for PLP binding exporter. We further suggest that this ABC-transporter in R. capsulatus is involved in the formation and export of polysulfide species to the periplasm. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 740 KW - ABCB7 KW - persulfide KW - polysulfide KW - glutathione KW - ABC transporter KW - Walker A motif KW - pyridoxal-50-phosphate Y1 - 1019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-434975 SN - 1866-8372 IS - 740 ER - TY - JOUR A1 - Riedel, Simona A1 - Siemiatkowska, Beata A1 - Watanabe, Mutsumi A1 - Müller, Christina S. A1 - Schünemann, Volker A1 - Hoefgen, Rainer A1 - Leimkühler, Silke T1 - The ABCB7-Like Transporter PexA in Rhodobacter capsulatus Is Involved in the Translocation of Reactive Sulfur Species JF - Frontiers in Microbiology N2 - The mitochondrial ATP-binding cassette (ABC) transporters ABCB7 in humans, Atm1 in yeast and ATM3 in plants, are highly conserved in their overall architecture and particularly in their glutathione binding pocket located within the transmembrane spanning domains. These transporters have attracted interest in the last two decades based on their proposed role in connecting the mitochondrial iron sulfur (Fe–S) cluster assembly with its cytosolic Fe–S cluster assembly (CIA) counterpart. So far, the specific compound that is transported across the membrane remains unknown. In this report we characterized the ABCB7-like transporter Rcc02305 in Rhodobacter capsulatus, which shares 47% amino acid sequence identity with its mitochondrial counterpart. The constructed interposon mutant strain in R. capsulatus displayed increased levels of intracellular reactive oxygen species without a simultaneous accumulation of the cellular iron levels. The inhibition of endogenous glutathione biosynthesis resulted in an increase of total glutathione levels in the mutant strain. Bioinformatic analysis of the amino acid sequence motifs revealed a potential aminotransferase class-V pyridoxal-50-phosphate (PLP) binding site that overlaps with the Walker A motif within the nucleotide binding domains of the transporter. PLP is a well characterized cofactor of L-cysteine desulfurases like IscS and NFS1 which has a role in the formation of a protein-bound persulfide group within these proteins. We therefore suggest renaming the ABCB7-like transporter Rcc02305 in R. capsulatus to PexA for PLP binding exporter. We further suggest that this ABC-transporter in R. capsulatus is involved in the formation and export of polysulfide species to the periplasm. KW - ABCB7 KW - persulfide KW - polysulfide KW - glutathione KW - ABC transporter KW - Walker A motif KW - pyridoxal-50-phosphate Y1 - 2019 U6 - https://doi.org/10.3389/fmicb.2019.00406 SN - 1664-302X VL - 10 PB - Frontiers Media CY - Lausanne ER - TY - THES A1 - Riedel, Simona T1 - Characterization of Mitochondrial ABC Transporter Homologues in Rhodobacter capsulatus T1 - Charakterisierung von Homologen zu mitochondrialen ABC Transportern in Rhodobacter capsulatus N2 - ABC-Transporter (ABC abgeleitet von ATP-Binding Cassette) gehören zur Klasse der Transmembran-Proteine und kommen in allen drei Domänen des Lebens vor. Ihr struktureller Aufbau ist dabei stets ähnlich, wohingegen konservierte Proteinsequenzen selten vorkommen. Die Transporter sind aus zwei lipophilen, membran-durchspannenden Domänen, welche auch TMDs (abgeleitet von Transmembrane spanning Domains) genannt werden, und zwei hydrophilen Domänen, die auch NBDs (abgeleitet von Nucleotide Binding Domains) genannt werden, aufgebaut. Die Vielzahl der durch ABC-Transporter beförderten Moleküle erklärt dabei die enorme Anzahl diverser TMDs. In den Mitochondrien des Menschen findet man vier ABC-Transporter (ABCB6, ABCB7, ABCB8 und ABCB10) mit funktionellen Homologen in Hefen und Pflanzen. In Bakterien hingegen können, mit Ausnahme von Rickettsiae und verwandten Bakterien, keine Homologen zu mitochondrialen ABC-Transportern identifiziert werden. Die transportierten Moleküle sowie die damit verbundenen Funktionen sind im Einzelnen bislang weitgehend unbekannt. ABCB7 und die entsprechenden Homologen in Hefen (Atm1) und in Pflanzen (ATM3) konnten mit der cytosolischen Eisen-Schwefel-Cluster-Biosynthese in Zusammenhang gebracht werden. Eine schwefelhaltige Verbindung der mitochondrialen Matrix wird mit Hilfe dieses Transporters der cytosolischen Eisen-Schwefel-Cluster-Assemblierung zur Verfügung gestellt. Die 2014 publizierten Kristallstrukturen von Atm1 (Hefe) und Atm1 aus Novosphingobium aromaticivorans offenbarten dabei eine hoch konservierte Glutathion-Bindetasche innerhalb der TMDs für ABCB7 Homologe. In der Modellpflanze Arabidopsis thaliana konnte ATM3 zusätzlich mit der Biosynthese des Molybdän-Cofaktors in Verbindung gebracht werden. In der vorliegenden Arbeit wurde das α-Proteobacterium Rhodobacter capsulatus als Modellorganismus genutzt, um mitochondriale ABC-Transporter Homologe zu untersuchen. Das Bakterium enthält zwei ABC-Transporter-Gene, rcc03139 und rcc02305, die mit den humanen mitochondrialen Transportern große Sequenzübereinstimmungen aufweisen (rcc03139: 41 % respektive 38 % Identität mit ABCB8 und ABCB10, rcc02305: 47 % identisch mit ABCB7 und ABCB6). Mit Hilfe erzeugter Interposon-Mutanten (Δrcc02305I und Δrcc03139I) konnte erstmals gezeigt werden, dass bakterielle Transporter funktionell sehr ähnliche Aufgaben wie die mitochondrialen ABC-Transporter übernehmen. Beispielsweise akkumulierten beide Interposon-Mutanten reaktive Sauerstoff-Spezies (ROS) ohne gleichzeitige Akkumulation von Glutathion oder Eisen. Weiterhin konnten wir zeigen, dass, ähnlich wie bereits für ATM3 postuliert, die Biosynthese des Molybdän-Cofaktors in Δrcc02305I verändert ist. Mit Hilfe einer lebensfähigen Doppelmutante, in der beide ABC-Transporter-Gene gleichzeitig deletiert wurden, konnten wir ausschließen, dass die beiden bakteriellen ABC-Transporter grundsätzlich redundante Funktionen haben. Durch die Analyse des Proteoms von Δrcc03139I im Vergleich zu der des Wildtyps, konnte eine extreme Beeinflussung der Tetrapyrrol Biosynthese sowie entsprechender Zielproteine identifiziert werden. Dies konnte zusätzlich durch die Quantifizierung einzelner Zwischenprodukte der Biosynthese bestätigt werden. Im Gegensatz dazu konnte anhand der Analyse des Proteoms in Verbindung mit analytischen Methoden in Δrcc02305I ein Ungleichgewicht in der Schwefelverteilung identifiziert werden. Zusammen mit der Entdeckung einer Pyridoxalphosphat (PLP) Bindestelle in Rcc02305 und anderen ABCB7-artigen Transportern, welche direkt mit dem Walker-A-Motiv der NBD überlappt, ermöglichte dies eine völlig neue Theorie, wie die schwefelhaltige Verbindung transportiert werden kann. Wir gehen davon aus, dass an PLP zunächst ein Persulfid produziert wird, welches unmittelbar mit dem Glutathion der transmembranen Bindetasche zu einem gemischten Polysulfid reagiert. Im Anschluss daran wird die ATP-Bindestelle frei und die Hydrolyse des ATPs löst eine Konformationsänderung aus, welche das gemischte Polysulfid ins Periplasma bzw. in den intermembranen Raum freigibt. N2 - ATP-binding cassette (ABC) transporters are present in all kingdoms of life and enable active transport of various different molecules across biological membranes. They all share an overall architecture of two lipophilic transmembrane spanning domains (TMDs) traversing the membrane and two hydrophilic nucleotide binding domains (NBDs) usually lacking sequence identity. The multiplicity in transported molecules is accompanied by extreme diversity in TMDs. Human mitochondria harbor four ABC transporters, namely ABCB6, ABCB7, ABCB8 and ABCB10 with functional homologues in yeast and plants. Except the ones found in Rickettsiae and related bacteria mitochondrial ABC transporters are absent in bacteria. In addition to converting energy mitochondria are important platforms for biosynthesizing various cofactors as iron sulfur clusters, molybdenum cofactor (Moco) or heme. ABCB7 (Atm1 in yeast) has been shown to connect mitochondrial with cytosolic iron sulfur cluster assembly by exporting a yet unknown sulfur containing molecule. In addition, TMDs of Atm1 display a glutathione binding pocket accessible from the matrix which has been identified in all ABCB7-like transporters and also exists in a bacterial ABC transporter homologue of Atm1 in Novosphingobium aromaticivorans. In addition, ATM3, a plant mitochondrial homologous ABC transporter to human ABCB7, has been associated with biosynthesizing Moco. In this study we used the α-proteobacterium Rhodobacter capsulatus as a model organism to characterize mitochondrial ABC transporter homologues. R. capsulatus contains two homologues to mitochondrial ABC transporters with the corresponding gene loci rcc03139 and rcc02305. They share 38 to 47 % sequence identities to human mitochondrial ABC transporters ABCB8/ABCB10 and ABCB7/ABCB6, respectively. We created interposon mutants lacking either rcc03139 or rcc02305, analyzed the physiological effects on R. capsulatus and compared the findings especially to eukaryotic deletion studies. A viable bacterial double mutant strain lacking both mitochondrial ABC transporters was constructed to investigate possible overlapping functions. Both R. capsulatus single mutants showed a severe accumulation of intracellular reactive oxygen species (ROS) in comparison to ∆nifDK which revealed to be additive in the double mutant. In the proteome of ∆rcc03139I abundancies of tetrapyrrole related proteins were significantly increased in comparison to the proteome of parental strain, which was further validated by reduced amounts of tetrapyrrole intermediates in ∆rcc03139. In contrast, in ∆rcc02305I total glutathione (GSH) was elevated when endogenous GSH biosynthesis was inhibited. In conjunction with proteomic studies we uncovered misbalanced sulfur distribution in ∆rcc02305I. Furthermore, strains lacking Rcc02305 accumulated cyclic pyranopterin monophosphate (cPMP), an intermediate of Moco biosynthesis, as it was already shown for the deletion strain of the eukaryotic counterpart ATM3 in plants. In contrast single mutant strain Δrcc03139I neither accumulated cPMP nor glutathione. Bioinformatic analysis of the amino acid sequence of Rcc02305 revealed a pyridoxal 5´phosphate (PLP) binding site which overlaps with Walker A within the NBDs of Rcc02305 and other ABCB7-like transporters. The PLP cofactor is well studied in C-DES (L-cysteine/cystine lyase from Synechocystis) for persulfide production and in L-cysteine desulfurases such as IscS and NFS1 for its role in formation of protein-bound persulfides. Based on our findings we are able to propose a new modality for the transport of the sulfur containing molecule: first of all, the transporter produces a highly reactive persulfide which is then subsequently trapped by glutathione polysulfide, already bound within the binding pocket in TMDs. Walker A becomes accessible for ATP and after hydrolysis the mixed polysulfide is released. Based on our studies we are convinced that both mitochondrial ABC transporter homologues fulfil distinct roles in R. capsulatus: Rcc02305 is a representative of Atm1/ABCB7-like transporters and important for proper sulfur distribution by exporting persulfides. In contrast Rcc03139 is a representative of ABCB6/ABCB10 related transporters and involved in biosynthesizing tetrapyrroles. KW - Rhodobacter capsulatus KW - ABC Transporter KW - ABCB7 KW - Mitochondrien KW - PLP-Walker A-Überlagerung KW - Rhodobacter capsulatus KW - ABC transporter KW - ABCB7 KW - mitochondria KW - PLP-Walker A-overlap Y1 - 2019 ER - TY - JOUR A1 - Rieck, Christoph Paul Kurt A1 - Geiger, Daniel A1 - Munkert, Jennifer A1 - Messerschmidt, Katrin A1 - Petersen, Jan A1 - Strasser, Juliane A1 - Meitinger, Nadine A1 - Kreis, Wolfgang T1 - Biosynthetic approach to combine the first steps of cardenolide formation in Saccharomyces cerevisiae JF - Microbiologyopen N2 - A yeast expression plasmid was constructed containing a cardenolide biosynthetic module, referred to as CARD II, using the AssemblX toolkit, which enables the assembly of large DNA constructs. The genes cloned into the vector were (a) a Δ5‐3β‐hydroxysteroid dehydrogenase gene from Digitalis lanata, (b) a steroid Δ5‐isomerase gene from Comamonas testosteronii, (c) a mutated steroid‐5β‐reductase gene from Arabidopsis thaliana, and (d) a steroid 21‐hydroxylase gene from Mus musculus. A second plasmid bearing an ADR/ADX fusion gene from Bos taurus was also constructed. A Saccharomyces cerevisiae strain bearing these two plasmids was generated. This strain, termed “CARD II yeast”, was capable of producing 5β‐pregnane‐3β,21‐diol‐20‐one, a central intermediate in 5β‐cardenolide biosynthesis, starting from pregnenolone which was added to the culture medium. Using this approach, five consecutive steps in cardenolide biosynthesis were realized in baker's yeast. Y1 - 2019 U6 - https://doi.org/10.1002/mbo3.925 SN - 2045-8827 VL - 8 IS - 12 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Reschke, Stefan A1 - Duffus, Benjamin R. A1 - Schrapers, Peer A1 - Mebs, Stefan A1 - Teutloff, Christian A1 - Dau, Holger A1 - Haumann, Michael A1 - Leimkühler, Silke T1 - Identification of YdhV as the First Molybdoenzyme Binding a Bis-Mo-MPT Cofactor in Escherichia coli JF - Biochemistry N2 - The oxidoreductase YdhV in Escherichia coli has been predicted to belong to the family of molybdenum/tungsten cofactor (Moco/Wco)-containing enzymes. In this study, we characterized the YdhV protein in detail, which shares amino acid sequence homology with a tungsten-containing benzoyl-CoA reductase binding the bis-W-MPT (for metal-binding pterin) cofactor. The cofactor was identified to be of a bis-Mo-MPT type with no guanine nucleotides present, which represents a form of Moco that has not been found previously in any molybdoenzyme. Our studies showed that YdhV has a preference for bis-Mo-MPT over bis-W-MPT to be inserted into the enzyme. In-depth characterization of YdhV by X-ray absorption and electron paramagnetic resonance spectroscopies revealed that the bis-Mo-MPT cofactor in YdhV is redox active. The bis-Mo-MPT and bis-W-MPT cofactors include metal centers that bind the four sulfurs from the two dithiolene groups in addition to a cysteine and likely a sulfido ligand. The unexpected presence of a bis-Mo-MPT cofactor opens an additional route for cofactor biosynthesis in E. coli and expands the canon of the structurally highly versatile molybdenum and tungsten cofactors. Y1 - 2019 U6 - https://doi.org/10.1021/acs.biochem.9b00078 SN - 0006-2960 VL - 58 IS - 17 SP - 2228 EP - 2242 PB - American Chemical Society CY - Washington ER - TY - JOUR A1 - Reimann, Anna A1 - Beyer, Rudolf A1 - Mumm, Rebekka A1 - Scheffler, Christiane T1 - Reference tables with centiles of limb to body height ratios of healthy human adults for assessing potential thalidomide embryopathy JF - Journal of biological and clinical anthropology : Anthropologischer Anzeiger ; Mitteilungsorgan der Gesellschaft für Anthropologie N2 - Background: Over 60 years ago the biggest drug catastrophe in Germany took place. The drug thalidomide, sold by the German pharmaceutical company Chemie Grunenthal GmbH starting in 1957 under the name "Contergan", caused severe birth defects in newborns. Chemie Grunenthal withdraw Contergan in 1961. Until nearly 30 years later in 1988 there were already over 10.000 children born with severe birth defects (e.g. dysmelia, amelia, congenital heart defect). Due to the high variability of the birth defects caused by thalidomide, later called thalidomide embryopathy, there is still no detailed information about the proportions of limbs. Aim: The aim is to develop reference centiles for limb measurements of men and women aged 19-70 years old. Method: For the calculation, data of healthy men and women (m = 2984, f = 2838) from former East Germany were used and centiles using the LMS-method were developed. Results: Centile tables for arm and leg length of men and women are presented in the results. The variability is small due to a homogeneous distribution of the measurements. A test with randomly chosen patient data shows that women under 171 cm stature and men under 180 cm stature can be assessed correctly. A severe shortening of limbs can be detected with this method. KW - thalidomide embryopathy KW - contergan KW - anthropometry KW - body proportions Y1 - 2019 U6 - https://doi.org/10.1127/anthranz/2019/0981 SN - 0003-5548 VL - 76 IS - 5 SP - 391 EP - 400 PB - Schweizerbart CY - Stuttgart ER - TY - THES A1 - Reeg, Jette T1 - Simulating the impact of herbicide drift exposure on non-target terrestrial plant communities T1 - Simulation der Auswirkungen von Herbizid-Drift-Expositionen auf Gemeinschaften von Nichtzielpflanzen N2 - In Europe, almost half of the terrestrial landscape is used for agriculture. Thus, semi-natural habitats such as field margins are substantial for maintaining diversity in intensively managed farmlands. However, plants located at field margins are threatened by agricultural practices such as the application of pesticides within the fields. Pesticides are chemicals developed to control for undesired species within agricultural fields to enhance yields. The use of pesticides implies, however, effects on non-target organisms within and outside of the agricultural fields. Non-target organisms are organisms not intended to be sprayed or controlled for. For example, plants occurring in field margins are not intended to be sprayed, however, can be impaired due to herbicide drift exposure. The authorization of plant protection products such as herbicides requires risk assessments to ensure that the application of the product has no unacceptable effects on the environment. For non-target terrestrial plants (NTTPs), the risk assessment is based on standardized greenhouse studies on plant individual level. To account for the protection of plant populations and communities under realistic field conditions, i.e. extrapolating from greenhouse studies to field conditions and from individual-level to community-level, assessment factors are applied. However, recent studies question the current risk assessment scheme to meet the specific protection goals for non-target terrestrial plants as suggested by the European Food Safety Authority (EFSA). There is a need to clarify the gaps of the current risk assessment and to include suitable higher tier options in the upcoming guidance document for non-target terrestrial plants. In my thesis, I studied the impact of herbicide drift exposure on NTTP communities using a mechanistic modelling approach. I addressed main gaps and uncertainties of the current risk assessment and finally suggested this modelling approach as a novel higher tier option in future risk assessments. Specifically, I extended the plant community model IBC-grass (Individual-based community model for grasslands) to reflect herbicide impacts on plant individuals. In the first study, I compared model predictions of short-term herbicide impacts on artificial plant communities with empirical data. I demonstrated the capability of the model to realistically reflect herbicide impacts. In the second study, I addressed the research question whether or not reproductive endpoints need to be included in future risk assessments to protect plant populations and communities. I compared the consequences of theoretical herbicide impacts on different plant attributes for long-term plant population dynamics in the community context. I concluded that reproductive endpoints only need to be considered if the herbicide effect is assumed to be very high. The endpoints measured in the current vegetative vigour and seedling emergence studies had high impacts for the dynamic of plant populations and communities already at lower effect intensities. Finally, the third study analysed long-term impacts of herbicide application for three different plant communities. This study highlighted the suitability of the modelling approach to simulate different communities and thus detecting sensitive environmental conditions. Overall, my thesis demonstrates the suitability of mechanistic modelling approaches to be used as higher tier options for risk assessments. Specifically, IBC-grass can incorporate available individual-level effect data of standardized greenhouse experiments to extrapolate to community-level under various environmental conditions. Thus, future risk assessments can be improved by detecting sensitive scenarios and including worst-case impacts on non-target plant communities. N2 - Fast die Hälfte der gesamten Landfläche in Europa wird für landwirtschaftliche Zwecke genutzt. Daher sind halb-natürliche Gebiete, wie zum Beispiel Ackerränder, von besonderer Bedeutung für den Artenreichtum in intensiv genutzten Ackerlandschaften. Vor allem in den intensiv genutzten Äckern werden Chemikalien eingesetzt um die Erträge zu erhöhen. So werden zum Beispiel Pflanzenschutzmittel eingesetzt, um Unkräuter im Acker zu vernichten. Allerdings kann dieser Einsatz auch Auswirkungen auf sogenannte Nicht-Zielarten haben. Dies sind solche Arten oder Artindividuen, die z.B. innerhalb vom Acker nicht in Konkurrenz mit den darauf wachsenden Getreidesorten stehen oder sich nicht innerhalb vom Feld befinden aber dennoch den Pflanzenschutzmitteln ausgesetzt sind. Um den Artenreichtum in halb-natürlichen Gebieten zu schützen, ist es daher notwendig eine Risikoabschätzung durchzuführen bevor ein Pflanzenschutzmittel für den Verkauf und die Anwendung zugelassen wird. Für terrestrische Nicht-Zielpflanzen erfolgt eine solche Risikoabschätzung basierend auf standardisierten Gewächshausexperimenten, in denen die Effekte auf der Ebene von Einzelindividuen gemessen werden. Um das letztliche Risiko im Freiland für ganze Pflanzengemeinschaften abzuschätzen, werden sogenannte Unsicherheitsfaktoren hinzugenommen. Allerdings stellen neuere Studien in Frage, ob der derzeitige Ansatz ausreichend sicher ist. Dies gilt vor allem in Bezug auf die aktuellen speziellen Schutzziele, die den Fokus auf den Schutz von Pflanzengemeinschaften und Artenreichtum legen. Es ist daher zwingend notwendig die Wissenslücken der derzeitigen Risikoabschätzung zu schließen und Optionen zu weiteren Studien zu geben, die das Risiko vom Einsatz von Pflanzenschutzmitteln für Nicht-Zielpflanzen realistischer abschätzen können. In meiner Dissertation nutze ich einen mechanistischen Modellierungsansatz um den Einfluss von Pflanzenschutzmitteln auf Nicht-Zielpflanzengemeinschaften zu untersuchen. Hierbei spreche ich die wesentlichen Wissenslücken und Unklarheiten der aktuellen Risikoabschätzung an und schlage zusammenfassend eine neue Option für eine realistischere Abschätzung des Risikos vor. Hierzu integriere ich den Einfluss von Herbiziden auf Einzelindividuen in das Pflanzengemeinschaftsmodell IBC-grass. In meiner ersten Studie vergleiche ich Modellvorhersagen von kurzzeitigen Herbizideffekten in künstlichen Artgemeinschaften mit experimentellen Daten. Mit der Studie zeige ich, dass das Modell den Einfluss von Herbiziden auf die Pflanzengemeinschaft realistisch vorhersagen kann. In der zweiten Studie fokussiere ich mich auf die Frage, ob Effekte auf weitere Pflanzeneigenschaften, insbesondere Fortpflanzungseigenschaften, wie zum Beispiel die Samenproduktion, im Rahmen der standardisierten Gewächshausstudien gemessen werden sollten. Die Studie zeigt, dass die derzeitig gemessenen Pflanzeneigenschaften am meisten Einfluss auf die Dynamiken einer Pflanzengesellschaft haben und somit schon geringe Schädigungen dieser Eigenschaften auf Individuenebene Auswirkungen für die Gemeinschaft haben. Dahingegen führten nur sehr starke Effekte auf die Fortpflanzungseigenschaften zu einem Einfluss auf Gemeinschaftsebene. Mit der letzten Studie zeige ich, dass der Modellansatz dazu genutzt werden kann Auswirkungen für unterschiedliche Pflanzengemeinschaften darzustellen. Zusammengefasst zeigen die Studien meiner Dissertation, dass mechanistische Modellierung eine geeignete Option für eine realistischere Risikoabschätzung ist. Auf Grund des besonderen Designs von IBC-grass können die durch derzeitige Gewächshausstudien zur Verfügung stehenden empirischen Daten in das Modell eingearbeitet werden und somit das Risiko auf Gemeinschaftsebene abgeschätzt werden. Mit Hilfe des Modells können mehrere Umweltbedingungen getestet werden und somit Extremszenarien abgedeckt werden. Meine Studien tragen dazu bei, zukünftige Risikoabschätzungen für Nicht-Zielpflanzen zu verbessern. KW - ecological modelling KW - pesticide KW - risk assessment KW - plant community KW - non-target organisms KW - ökologische Modellierung KW - Pestizide KW - Risikoabschätzung KW - Pflanzengemeinschaft KW - Nicht-Zielorganismen Y1 - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-429073 ER -