@article{FeddersMuenznerWeberetal.2021, author = {Fedders, Ronja and Muenzner, Matthias and Weber, Pamela and Sommerfeld, Manuela and Knauer, Miriam and Kedziora, Sarah and Kast, Naomi and Heidenreich, Steffi and Raila, Jens and Weger, Stefan and Henze, Andrea and Schupp, Michael}, title = {Liver-secreted RBP4 does not impair glucose homeostasis in mice}, series = {The journal of biological chemistry}, volume = {293}, journal = {The journal of biological chemistry}, number = {39}, publisher = {American Society for Biochemistry and Molecular Biology}, address = {Bethesda}, issn = {1083-351X}, doi = {10.1074/jbc.RA118.004294}, pages = {15269 -- 15276}, year = {2021}, abstract = {Retinol-binding protein 4 (RBP4) is the major transport protein for retinol in blood. Recent evidence from genetic mouse models shows that circulating RBP4 derives exclusively from hepatocytes. Because RBP4 is elevated in obesity and associates with the development of glucose intolerance and insulin resistance, we tested whether a liver-specific overexpression of RBP4 in mice impairs glucose homeostasis. We used adeno-associated viruses (AAV) that contain a highly liver-specific promoter to drive expression of murine RBP4 in livers of adult mice. The resulting increase in serum RBP4 levels in these mice was comparable with elevated levels that were reported in obesity. Surprisingly, we found that increasing circulating RBP4 had no effect on glucose homeostasis. Also during a high-fat diet challenge, elevated levels of RBP4 in the circulation failed to aggravate the worsening of systemic parameters of glucose and energy homeostasis. These findings show that liver-secreted RBP4 does not impair glucose homeostasis. We conclude that a modest increase of its circulating levels in mice, as observed in the obese, insulin-resistant state, is unlikely to be a causative factor for impaired glucose homeostasis.}, language = {en} } @phdthesis{KnoxBrown2021, author = {Knox-Brown, Patrick Frank}, title = {Towards understanding the sequence-structure-function relationship of intrinsically disordered LEA_4 proteins from Arabidopsis thaliana}, school = {Universit{\"a}t Potsdam}, pages = {172, XI}, year = {2021}, abstract = {Water-deficits can cause lethal damage to organisms, which is rooted in cellular dehydration. Many plant species, but also other organisms have developed mechanisms to tolerate such stresses, such as the expression of LEA proteins. Many studies report on physiological protective functions of LEA proteins but lack information about their precise mechanisms on a molecular level. Most LEA proteins are intrinsically disordered in dilute solution but may adopt a distinct secondary structure upon changes in solvent conditions. Understanding the molecular mechanism of how LEA proteins contribute to the counteraction of cellular damage during water-deficits may in the long-term pave the way for breeding crops that are resistant to the effects of global warming. The objective of the work at hand is to improve the biophysical understanding of the sequencestructure-function relationship of LEA proteins as membrane stabilizers, based on the LEA_4 family of the model plant A. thaliana. This is pursued by using a combination of spectroscopic and scattering techniques, supported by bioinformatics and computational analyses. Eight out of the 18 LEA_4 proteins are experimentally assessed revealing that a coil-helix transition in response to water-deficit is a common feature, as predicted for the entire family. In addition, they all stabilize simple membrane models during a freeze/ thaw cycle. Three-dimensional structure prediction of representative members suggests that their completely folded states are represented by a sequential arrangement of alpha-helical segments connected by unstructured linkers, which is experimentally verified for the LEA_4 protein COR15A. The unstructured linker region of COR15A represents a conserved motif among its closest homologs and is, therefore, of particular interest. Facilitating a set of seven designed and investigated COR15A mutants uncovers a complex interplay of transient interactions between the amphipathic alpha-helical segments, mediated by the linker, which fine-tunes folding transitions and structural ensembles upon reduced water-availability. Finally, alpha-helicity is also induced in COR15A upon temperature decrease, which is enhanced in the presence of osmolytes. In addition, high solution osmolarity induced secondary structure is followed by oligomerization of COR15A. Interestingly, the functionality of COR15A, in terms of liposome stabilization, strongly correlates with its alpha-helix ratio in the folded state. The present work significantly improves the understanding of the sequence-structure-function relationship for LEA_4 proteins and offers novel findings on folding mechanisms and oligomerization of COR15A.}, language = {en} } @inproceedings{InaebnitDennis2021, author = {In{\"a}bnit, Thomas and Dennis, Alice}, title = {The mitochondrial genome of Melampus bidentatus (Panpulmonata, Ellobioidea)}, series = {Integrative and comparative biology / Society of Integrative and Comparative Biology}, volume = {61}, booktitle = {Integrative and comparative biology / Society of Integrative and Comparative Biology}, number = {Supplement 1}, publisher = {Oxford University Press}, address = {Oxford}, issn = {1540-7063}, pages = {E405 -- E405}, year = {2021}, language = {en} } @article{WojcikCeulemansGaedke2021, author = {Wojcik, Laurie Anne and Ceulemans, Ruben and Gaedke, Ursula}, title = {Functional diversity buffers the effects of a pulse perturbation on the dynamics of tritrophic food webs}, series = {Ecology and Evolution}, volume = {11}, journal = {Ecology and Evolution}, number = {22}, publisher = {John Wiley \& Sons, Inc.}, address = {Hoboken (New Jersey)}, issn = {2045-7758}, doi = {10.1002/ece3.8214}, pages = {15639 -- 15663}, year = {2021}, abstract = {Biodiversity decline causes a loss of functional diversity, which threatens ecosystems through a dangerous feedback loop: This loss may hamper ecosystems' ability to buffer environmental changes, leading to further biodiversity losses. In this context, the increasing frequency of human-induced excessive loading of nutrients causes major problems in aquatic systems. Previous studies investigating how functional diversity influences the response of food webs to disturbances have mainly considered systems with at most two functionally diverse trophic levels. We investigated the effects of functional diversity on the robustness, that is, resistance, resilience, and elasticity, using a tritrophic—and thus more realistic—plankton food web model. We compared a non-adaptive food chain with no diversity within the individual trophic levels to a more diverse food web with three adaptive trophic levels. The species fitness differences were balanced through trade-offs between defense/growth rate for prey and selectivity/half-saturation constant for predators. We showed that the resistance, resilience, and elasticity of tritrophic food webs decreased with larger perturbation sizes and depended on the state of the system when the perturbation occurred. Importantly, we found that a more diverse food web was generally more resistant and resilient but its elasticity was context-dependent. Particularly, functional diversity reduced the probability of a regime shift toward a non-desirable alternative state. The basal-intermediate interaction consistently determined the robustness against a nutrient pulse despite the complex influence of the shape and type of the dynamical attractors. This relationship was strongly influenced by the diversity present and the third trophic level. Overall, using a food web model of realistic complexity, this study confirms the destructive potential of the positive feedback loop between biodiversity loss and robustness, by uncovering mechanisms leading to a decrease in resistance, resilience, and potentially elasticity as functional diversity declines.}, language = {en} } @article{WolffGastEversetal.2021, author = {Wolff, Martin and Gast, Klaus and Evers, Andreas and Kurz, Michael and Pfeiffer-Marek, Stefania and Sch{\"u}ler, Anja and Seckler, Robert and Thalhammer, Anja}, title = {A Conserved Hydrophobic Moiety and Helix-Helix Interactions Drive the Self-Assembly of the Incretin Analog Exendin-4}, series = {Biomolecules}, volume = {11}, journal = {Biomolecules}, number = {9}, publisher = {MDPI}, address = {Basel}, issn = {2218-273X}, doi = {10.3390/biom11091305}, pages = {20}, year = {2021}, abstract = {Exendin-4 is a pharmaceutical peptide used in the control of insulin secretion. Structural information on exendin-4 and related peptides especially on the level of quaternary structure is scarce. We present the first published association equilibria of exendin-4 directly measured by static and dynamic light scattering. We show that exendin-4 oligomerization is pH dependent and that these oligomers are of low compactness. We relate our experimental results to a structural hypothesis to describe molecular details of exendin-4 oligomers. Discussion of the validity of this hypothesis is based on NMR, circular dichroism and fluorescence spectroscopy, and light scattering data on exendin-4 and a set of exendin-4 derived peptides. The essential forces driving oligomerization of exendin-4 are helix-helix interactions and interactions of a conserved hydrophobic moiety. Our structural hypothesis suggests that key interactions of exendin-4 monomers in the experimentally supported trimer take place between a defined helical segment and a hydrophobic triangle constituted by the Phe22 residues of the three monomeric subunits. Our data rationalize that Val19 might function as an anchor in the N-terminus of the interacting helix-region and that Trp25 is partially shielded in the oligomer by C-terminal amino acids of the same monomer. Our structural hypothesis suggests that the Trp25 residues do not interact with each other, but with C-terminal Pro residues of their own monomers.}, language = {en} } @phdthesis{Ting2021, author = {Ting, Michael Kien Yin}, title = {Circadian-regulated dynamics of translation in Arabidopsis thaliana}, school = {Universit{\"a}t Potsdam}, pages = {130}, year = {2021}, language = {en} } @phdthesis{Brunacci2021, author = {Brunacci, Nadia}, title = {Oligodepsipeptides as matrix for drug delivery systems and submicron particulate carriers}, school = {Universit{\"a}t Potsdam}, year = {2021}, language = {en} } @article{GarridoLeimkuehler2021, author = {Garrido, Claudia and Leimk{\"u}hler, Silke}, title = {The inactivation of human aldehyde oxidase 1 by hydrogen peroxide and superoxide}, series = {Drug metabolism and disposition / American Society for Pharmacology and Experimental Therapeutics}, volume = {49}, journal = {Drug metabolism and disposition / American Society for Pharmacology and Experimental Therapeutics}, number = {9}, publisher = {American Society for Pharmacology and Experimental Therapeutics}, address = {Bethesda}, issn = {1521-009X}, doi = {10.1124/dmd.121.000549}, pages = {729 -- 735}, year = {2021}, abstract = {Mammalian aldehyde oxidases (AOX) are molybdo-flavoenzymes of pharmacological and pathophysiologic relevance that are involved in phase I drug metabolism and, as a product of their enzymatic activity, are also involved in the generation of reactive oxygen species. So far, the physiologic role of aldehyde oxidase 1 in the human body remains unknown. The human enzyme hAOX1 is characterized by a broad substrate specificity, oxidizing aromatic/aliphatic aldehydes into their corresponding carboxylic acids, and hydroxylating various heteroaromatic rings. The enzyme uses oxygen as terminal electron acceptor to produce hydrogen peroxide and superoxide during turnover. Since hAOX1 and, in particular, some natural variants produce not only H2O2 but also high amounts of superoxide, we investigated the effect of both ROS molecules on the enzymatic activity of hAOX1 in more detail. We compared hAOX1 to the high-O-2(.-)-producing natural variant L438V for their time-dependent inactivation with H2O2/O-2(.-) during substrate turnover. We show that the inactivation of the hAOX1 wild-type enzyme is mainly based on the production of hydrogen peroxide, whereas for the variant L438V, both hydrogen peroxide and superoxide contribute to the time-dependent inactivation of the enzyme during turnover. Further, the level of inactivation was revealed to be substrate-dependent: using substrates with higher turnover numbers resulted in a faster inactivation of the enzymes. Analysis of the inactivation site of the enzyme identified a loss of the terminal sulfido ligand at the molybdenum active site by the produced ROS during turnover.}, language = {en} } @article{CeulemansGuillGaedke2021, author = {Ceulemans, Ruben and Guill, Christian and Gaedke, Ursula}, title = {Top predators govern multitrophic diversity effects in tritrophic food webs}, series = {Ecology : a publication of the Ecological Society of America}, volume = {102}, journal = {Ecology : a publication of the Ecological Society of America}, number = {7}, publisher = {Wiley}, address = {Hoboken}, issn = {0012-9658}, doi = {10.1002/ecy.3379}, pages = {16}, year = {2021}, abstract = {It is well known that functional diversity strongly affects ecosystem functioning. However, even in rather simple model communities consisting of only two or, at best, three trophic levels, the relationship between multitrophic functional diversity and ecosystem functioning appears difficult to generalize, because of its high contextuality. In this study, we considered several differently structured tritrophic food webs, in which the amount of functional diversity was varied independently on each trophic level. To achieve generalizable results, largely independent of parametrization, we examined the outcomes of 128,000 parameter combinations sampled from ecologically plausible intervals, with each tested for 200 randomly sampled initial conditions. Analysis of our data was done by training a random forest model. This method enables the identification of complex patterns in the data through partial dependence graphs, and the comparison of the relative influence of model parameters, including the degree of diversity, on food-web properties. We found that bottom-up and top-down effects cascade simultaneously throughout the food web, intimately linking the effects of functional diversity of any trophic level to the amount of diversity of other trophic levels, which may explain the difficulty in unifying results from previous studies. Strikingly, only with high diversity throughout the whole food web, different interactions synergize to ensure efficient exploitation of the available nutrients and efficient biomass transfer to higher trophic levels, ultimately leading to a high biomass and production on the top level. The temporal variation of biomass showed a more complex pattern with increasing multitrophic diversity: while the system initially became less variable, eventually the temporal variation rose again because of the increasingly complex dynamical patterns. Importantly, top predator diversity and food-web parameters affecting the top trophic level were of highest importance to determine the biomass and temporal variability of any trophic level. Overall, our study reveals that the mechanisms by which diversity influences ecosystem functioning are affected by every part of the food web, hampering the extrapolation of insights from simple monotrophic or bitrophic systems to complex natural food webs.}, language = {en} } @article{SauerGrebe2021, author = {Sauer, Michael and Grebe, Markus}, title = {Plant cell biology}, series = {Current biology : CB}, volume = {31}, journal = {Current biology : CB}, number = {9}, publisher = {Cell Press}, address = {Cambridge}, issn = {0960-9822}, doi = {10.1016/j.cub.2021.03.070}, pages = {R449 -- R451}, year = {2021}, abstract = {PIN-FORMED (PIN) polar protein localization directs transport of the growth and developmental regulator auxin in plants. Once established after cytokinesis, PIN polarity requires maintenance. Now, direct interactions between PIN, MAB4/MEL and PID proteins suggest self-reinforced maintenance of PIN polarity through limiting lateral diffusion.}, language = {en} } @phdthesis{Tung2021, author = {Tung, Wing Tai}, title = {Polymeric fibrous scaffold on macro/microscale towards tissue regeneration}, school = {Universit{\"a}t Potsdam}, year = {2021}, language = {en} } @article{StarkBachGuill2021, author = {Stark, Markus and Bach, Moritz and Guill, Christian}, title = {Patch isolation and periodic environmental disturbances have idiosyncratic effects on local and regional population variabilities in meta-food chains}, series = {Theoretical ecology}, volume = {14}, journal = {Theoretical ecology}, number = {3}, publisher = {Springer}, address = {Dordrecht}, issn = {1874-1738}, doi = {10.1007/s12080-021-00510-0}, pages = {489 -- 500}, year = {2021}, abstract = {While habitat loss is a known key driver of biodiversity decline, the impact of other landscape properties, such as patch isolation, is far less clear. When patch isolation is low, species may benefit from a broader range of foraging opportunities, but are at the same time adversely affected by higher predation pressure from mobile predators. Although previous approaches have successfully linked such effects to biodiversity, their impact on local and metapopulation dynamics has largely been ignored. Since population dynamics may also be affected by environmental disturbances that temporally change the degree of patch isolation, such as periodic changes in habitat availability, accurate assessment of its link with isolation is highly challenging. To analyze the effect of patch isolation on the population dynamics on different spatial scales, we simulate a three-species meta-food chain on complex networks of habitat patches and assess the average variability of local populations and metapopulations, as well as the level of synchronization among patches. To evaluate the impact of periodic environmental disturbances, we contrast simulations of static landscapes with simulations of dynamic landscapes in which 30 percent of the patches periodically become unavailable as habitat. We find that increasing mean patch isolation often leads to more asynchronous population dynamics, depending on the parameterization of the food chain. However, local population variability also increases due to indirect effects of increased dispersal mortality at high mean patch isolation, consequently destabilizing metapopulation dynamics and increasing extinction risk. In dynamic landscapes, periodic changes of patch availability on a timescale much slower than ecological interactions often fully synchronize the dynamics. Further, these changes not only increase the variability of local populations and metapopulations, but also mostly overrule the effects of mean patch isolation. This may explain the often small and inconclusive impact of mean patch isolation in natural ecosystems.}, language = {en} } @article{GuillHuelsemannKlauschies2021, author = {Guill, Christian and H{\"u}lsemann, Janne and Klauschies, Toni}, title = {Self-organised pattern formation increases local diversity in metacommunities}, series = {Ecology letters}, volume = {24}, journal = {Ecology letters}, number = {12}, publisher = {Wiley-Blackwell}, address = {Oxford}, issn = {1461-023X}, doi = {10.1111/ele.13880}, pages = {2624 -- 2634}, year = {2021}, abstract = {Self-organised formation of spatial patterns is known from a variety of different ecosystems, yet little is known about how these patterns affect the diversity of communities. Here, we use a food chain model in which autotroph diversity is described by a continuous distribution of a trait that affects both growth and defence against heterotrophs. On isolated patches, diversity is always lost over time due to stabilising selection, and the local communities settle on one of two alternative stable community states that are characterised by a dominance of either defended or undefended species. In a metacommunity context, dispersal can destabilise these states and complex spatio-temporal patterns in the species' abundances emerge. The resulting biomass-trait feedback increases local diversity by an order of magnitude compared to scenarios without self-organised pattern formation, thereby maintaining the ability of communities to adapt to potential future changes in biotic or abiotic environmental conditions.}, language = {en} } @article{RomeroMujalliRochowKahletal.2021, author = {Romero-Mujalli, Daniel and Rochow, Markus and Kahl, Sandra M. and Paraskevopoulou, Sofia and Folkertsma, Remco and Jeltsch, Florian and Tiedemann, Ralph}, title = {Adaptive and nonadaptive plasticity in changing environments: Implications for sexual species with different life history strategies}, series = {Ecology and Evolution}, volume = {11}, journal = {Ecology and Evolution}, number = {11}, publisher = {John Wiley \& Sons, Inc.}, address = {New Jersey}, issn = {2045-7758}, pages = {17}, year = {2021}, abstract = {Populations adapt to novel environmental conditions by genetic changes or phenotypic plasticity. Plastic responses are generally faster and can buffer fitness losses under variable conditions. Plasticity is typically modeled as random noise and linear reaction norms that assume simple one-to- one genotype-phenotype maps and no limits to the phenotypic response. Most studies on plasticity have focused on its effect on population viability. However, it is not clear, whether the advantage of plasticity depends solely on environmental fluctuations or also on the genetic and demographic properties (life histories) of populations. Here we present an individual-based model and study the relative importance of adaptive and nonadaptive plasticity for populations of sexual species with different life histories experiencing directional stochastic climate change. Environmental fluctuations were simulated using differentially autocorrelated climatic stochasticity or noise color, and scenarios of directiona climate change. Nonadaptive plasticity was simulated as a random environmental effect on trait development, while adaptive plasticity as a linear, saturating, or sinusoidal reaction norm. The last two imposed limits to the plastic response and emphasized flexible interactions of the genotype with the environment. Interestingly, this assumption led to (a) smaller phenotypic than genotypic variance in the population (many-to- one genotype-phenotype map) and the coexistence of polymorphisms, and (b) the maintenance of higher genetic variation—compared to linear reaction norms and genetic determinism—even when the population was exposed to a constant environment for several generations. Limits to plasticity led to genetic accommodation, when costs were negligible, and to the appearance of cryptic variation when limits were exceeded. We found that adaptive plasticity promoted population persistence under red environmental noise and was particularly important for life histories with low fecundity. Populations produing more offspring could cope with environmental fluctuations solely by genetic changes or random plasticity, unless environmental change was too fast.}, language = {en} } @article{CahsanWestburyParaskevopoulouetal.2021, author = {Cahsan, Binia De and Westbury, Michael V. and Paraskevopoulou, Sofia and Drews, Hauke and Ott, Moritz and Gollmann, G{\"u}nter and Tiedemann, Ralph}, title = {Genomic consequences of human-mediated translocations in margin populations of an endangered amphibian}, series = {Evolutionary Applications}, volume = {14}, journal = {Evolutionary Applications}, number = {6}, publisher = {John Wiley \& Sons, Inc.}, address = {New Jersey}, issn = {1752-4563}, pages = {12}, year = {2021}, abstract = {Due to their isolated and often fragmented nature, range margin populations are especially vulnerable to rapid environmental change. To maintain genetic diversity and adaptive potential, gene flow from disjunct populations might therefore be crucial to their survival. Translocations are often proposed as a mitigation strategy to increase genetic diversity in threatened populations. However, this also includes the risk of losing locally adapted alleles through genetic swamping. Human-mediated translocations of southern lineage specimens into northern German populations of the endangered European fire-bellied toad (Bombina bombina) provide an unexpected experimental set-up to test the genetic consequences of an intraspecific introgression from central population individuals into populations at the species range margin. Here, we utilize complete mitochondrial genomes and transcriptome nuclear data to reveal the full genetic extent of this translocation and the consequences it may have for these populations. We uncover signs of introgression in four out of the five northern populations investigated, including a number of introgressed alleles ubiquitous in all recipient populations, suggesting a possible adaptive advantage. Introgressed alleles dominate at the MTCH2 locus, associated with obesity/fat tissue in humans, and the DSP locus, essential for the proper development of epidermal skin in amphibians. Furthermore, we found loci where local alleles were retained in the introgressed populations, suggesting their relevance for local adaptation. Finally, comparisons of genetic diversity between introgressed and nonintrogressed northern German populations revealed an increase in genetic diversity in all German individuals belonging to introgressed populations, supporting the idea of a beneficial transfer of genetic variation from Austria into North Germany.}, language = {en} } @article{SpikesRodriguezSilvaBennettetal.2021, author = {Spikes, Montrai and Rodr{\´i}guez-Silva, Rodet and Bennett, Kerri-Ann and Br{\"a}ger, Stefan and Josaphat, James and Torres-Pineda, Patricia and Ernst, Anja and Havenstein, Katja and Schlupp, Ingo and Tiedemann, Ralph}, title = {A phylogeny of the genus Limia (Teleostei: Poeciliidae) suggests a single-lake radiation nested in a Caribbean-wide allopatric speciation scenario}, series = {BMC Research Notes}, volume = {14}, journal = {BMC Research Notes}, publisher = {BMC Research Notes / Biomed Central}, address = {London}, issn = {1756-0500}, doi = {10.1186/s13104-021-05843-x}, pages = {1 -- 8}, year = {2021}, abstract = {Objective The Caribbean is an important global biodiversity hotspot. Adaptive radiations there lead to many speciation events within a limited period and hence are particularly prominent biodiversity generators. A prime example are freshwater fish of the genus Limia, endemic to the Greater Antilles. Within Hispaniola, nine species have been described from a single isolated site, Lake Mirago{\^a}ne, pointing towards extraordinary sympatric speciation. This study examines the evolutionary history of the Limia species in Lake Mirago{\^a}ne, relative to their congeners throughout the Caribbean. Results For 12 Limia species, we obtained almost complete sequences of the mitochondrial cytochrome b gene, a well-established marker for lower-level taxonomic relationships. We included sequences of six further Limia species from GenBank (total N  = 18 species). Our phylogenies are in concordance with other published phylogenies of Limia. There is strong support that the species found in Lake Mirago{\^a}ne in Haiti are monophyletic, confirming a recent local radiation. Within Lake Mirago{\^a}ne, speciation is likely extremely recent, leading to incomplete lineage sorting in the mtDNA. Future studies using multiple unlinked genetic markers are needed to disentangle the relationships within the Lake Mirago{\^a}ne clade.}, language = {en} } @article{KruegerFoersterTrauthetal.2021, author = {Kr{\"u}ger, Johanna and Foerster, Verena Elisabeth and Trauth, Martin H. and Hofreiter, Michael and Tiedemann, Ralph}, title = {Exploring the Past Biosphere of Chew Bahir/Southern Ethiopia: Cross-Species Hybridization Capture of Ancient Sedimentary DNA from a Deep Drill Core}, series = {Frontiers in Earth Science}, journal = {Frontiers in Earth Science}, publisher = {Frontiers in Earth Science}, address = {Lausanne, Schweiz}, issn = {2296-6463}, doi = {10.3389/feart.2021.683010}, pages = {1 -- 20}, year = {2021}, abstract = {Eastern Africa has been a prime target for scientific drilling because it is rich in key paleoanthropological sites as well as in paleolakes, containing valuable paleoclimatic information on evolutionary time scales. The Hominin Sites and Paleolakes Drilling Project (HSPDP) explores these paleolakes with the aim of reconstructing environmental conditions around critical episodes of hominin evolution. Identification of biological taxa based on their sedimentary ancient DNA (sedaDNA) traces can contribute to understand past ecological and climatological conditions of the living environment of our ancestors. However, sedaDNA recovery from tropical environments is challenging because high temperatures, UV irradiation, and desiccation result in highly degraded DNA. Consequently, most of the DNA fragments in tropical sediments are too short for PCR amplification. We analyzed sedaDNA in the upper 70 m of the composite sediment core of the HSPDP drill site at Chew Bahir for eukaryotic remnants. We first tested shotgun high throughput sequencing which leads to metagenomes dominated by bacterial DNA of the deep biosphere, while only a small fraction was derived from eukaryotic, and thus probably ancient, DNA. Subsequently, we performed cross-species hybridization capture of sedaDNA to enrich ancient DNA (aDNA) from eukaryotic remnants for paleoenvironmental analysis, using established barcoding genes (cox1 and rbcL for animals and plants, respectively) from 199 species that may have had relatives in the past biosphere at Chew Bahir. Metagenomes yielded after hybridization capture are richer in reads with similarity to cox1 and rbcL in comparison to metagenomes without prior hybridization capture. Taxonomic assignments of the reads from these hybridization capture metagenomes also yielded larger fractions of the eukaryotic domain. For reads assigned to cox1, inferred wet periods were associated with high inferred relative abundances of putative limnic organisms (gastropods, green algae), while inferred dry periods showed increased relative abundances for insects. These findings indicate that cross-species hybridization capture can be an effective approach to enhance the information content of sedaDNA in order to explore biosphere changes associated with past environmental conditions, enabling such analyses even under tropical conditions.}, language = {en} } @article{Trindade2021, author = {Trindade, In{\^e}s}, title = {License to flower}, series = {Molecular plant}, volume = {14}, journal = {Molecular plant}, number = {5}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {1674-2052}, doi = {10.1016/j.molp.2021.04.007}, pages = {719 -- 720}, year = {2021}, language = {en} } @article{OberkoflerPratxBaeurle2021, author = {Oberkofler, Vicky and Pratx, Loris and B{\"a}urle, Isabel}, title = {Epigenetic regulation of abiotic stress memory}, series = {Current opinion in plant biology}, volume = {61}, journal = {Current opinion in plant biology}, publisher = {Elsevier}, address = {London}, issn = {1369-5266}, doi = {10.1016/j.pbi.2021.102007}, pages = {7}, year = {2021}, abstract = {As sessile organisms, plants have evolved sophisticated ways to constantly gauge and adapt to changing environmental conditions including extremes that may be harmful to their growth and development and are thus perceived as stress. In nature, stressful events are often chronic or recurring and thus an initial stress may prime a plant to respond more efficiently to a subsequent stress event. An epigenetic basis of such stress memory was long postulated and in recent years it has been shown that this is indeed the case. High temperature stress has proven an excellent system to unpick the molecular basis of somatic stress memory, which includes histone modifications and nucleosome occupancy. This review discusses recent findings and pinpoints open questions in the field.}, language = {en} } @article{GraefGrafeMeyeretal.2021, author = {Gr{\"a}f, Ralph and Grafe, Marianne and Meyer, Irene and Mitic, Kristina and Pitzen, Valentin}, title = {The dictyostelium centrosome}, series = {Cells : open access journal}, volume = {10}, journal = {Cells : open access journal}, number = {10}, publisher = {MDPI}, address = {Basel}, issn = {2073-4409}, doi = {10.3390/cells10102657}, pages = {26}, year = {2021}, abstract = {The centrosome of Dictyostelium amoebae contains no centrioles and consists of a cylindrical layered core structure surrounded by a corona harboring microtubule-nucleating gamma-tubulin complexes. It is the major centrosomal model beyond animals and yeasts. Proteomics, protein interaction studies by BioID and superresolution microscopy methods led to considerable progress in our understanding of the composition, structure and function of this centrosome type. We discuss all currently known components of the Dictyostelium centrosome in comparison to other centrosomes of animals and yeasts.}, language = {en} }