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Intensive land use is a major cause of biodiversity loss, but most studies comparing the response of multiple taxa rely on simple diversity measures while analyses of other community attributes are only recently gaining attention. Species-abundance distributions (SADs) are a community attribute that can be used to study changes in the overall abundance structure of species groups, and whether these changes are driven by abundant or rare species. We evaluated the effect of grassland management intensity for three land-use modes (fertilization, mowing, grazing) and their combination on species richness and SADs for three belowground (arbuscular mycorrhizal fungi, prokaryotes and insect larvae) and seven aboveground groups (vascular plants, bryophytes and lichens; arthropod herbivores; arthropod pollinators; bats and birds). Three descriptors of SADs were evaluated: general shape (abundance decay rate), proportion of rare species (rarity) and proportional abundance of the commonest species (dominance). Across groups, taxonomic richness was largely unaffected by land-use intensity and only decreased with increasing mowing intensity. Of the three SAD descriptors, abundance decay rate became steeper with increasing combined land-use intensity across groups. This reflected a decrease in rarity among plants, herbivores and vertebrates. Effects of fertilization on the three descriptors were similar to the combined land-use intensity effects. Mowing intensity only affected the SAD descriptors of insect larvae and vertebrates, while grazing intensity produced a range of effects on different descriptors in distinct groups. Overall, belowground groups had more even abundance distribtitions than aboveground groups. Strong differences among aboveground groups and between above- and belowground groups indicate that no single taxonomic group can serve as an indicator for effects in other groups. In the past, the use of SADs has been hampered by concerns over theoretical models underlying specific forms of SADs. Our study shows that SAD descriptors that are not connected to a particular model are suitable to assess the effect of land use on community structure.
The acentriolar Dictyostelium centrosome is a nucleus-associated body consisting of a core structure with three plaque-like layers, which are surrounded by a microtubule-nucleating corona. The core duplicates once per cell cycle at the G2/M transition, whereby its central layer disappears and the two outer layers form the mitotic spindle poles. Through proteomic analysis of isolated centrosomes, we have identified CP39 and CP75, two essential components of the core structure. Both proteins can be assigned to the central core layer as their centrosomal presence is correlated to the disappearance and reappearance of the central core layer in the course of centrosome duplication. Both proteins contain domains with centrosome-binding activity in their N- and C-terminal halves, whereby the respective N-terminal half is required for cell cycle-dependent regulation. CP39 is capable of self-interaction and GFP-CP39 overexpression elicited supernumerary microtubule-organizing centers and pre-centrosomal cytosolic clusters. Underexpression stopped cell growth and reversed the MTOC amplification phenotype. In contrast, in case of CP75 underexpression of the protein by RNAi treatment elicited supernumerary MTOCs. In addition, CP75RNAi affects correct chromosome segregation and causes co-depletion of CP39 and CP91, another central core layer component. CP39 and CP75 interact with each other directly in a yeast two-hybrid assay. Furthermore, CP39, CP75 and CP91 mutually interact in a proximity-dependent biotin identification (BioID) assay. Our data indicate that these three proteins are all required for proper centrosome biogenesis and make up the major structural components of core structure's central layer.
Inhibition of MAP kinase pathways by selective BRAF inhibitors, such as vemurafenib and dabrafenib, have evolved as key therapies of BRAF-mutated melanoma. However, tumor relapse and therapy resistance have remained as major problems, which may be addressed by combination with other pathway inhibitors. Here we identified the potassium channel inhibitor TRAM-34 as highly effective in combination with vemurafenib. Thus apoptosis was significantly enhanced and cell viability was decreased. The combination vemurafenib/TRAM-34 was also effective in vemurafenib-resistant cells, suggesting that acquired resistance may be overcome. Vemurafenib decreased ERK phosphorylation, suppressed antiapoptotic Mcl-1 and enhanced proapoptotic Puma and Bim. The combination resulted in enhancement of proapoptotic pathways as caspase-3 and loss of mitochondrial membrane potential. Indicating a special mechanism of vemurafenib-induced apoptosis, we found strong enhancement of intracellular ROS levels already at 1 h of treatment. The critical role of ROS was demonstrated by the antioxidant vitamin E (alpha-tocopherol), which decreased intracellular ROS as well as apoptosis. Also caspase activation and loss of mitochondrial membrane potential were suppressed, proving ROS as an upstream effect. Thus ROS represents an initial and independent apoptosis pathway in melanoma cells that is of particular importance for vemurafenib and its combination with TRAM-34.
Background
Protected areas are the most common and important instrument for the conservation of biological diversity and are called for under the United Nations' Convention on Biological Diversity. Growing human population densities, intensified land-use, invasive species and increasing habitat fragmentation threaten ecosystems worldwide and protected areas are often the only refuge for endangered species. Climate change is posing an additional threat that may also impact ecosystems currently under protection. Therefore, it is of crucial importance to include the potential impact of climate change when designing future nature conservation strategies and implementing protected area management. This approach would go beyond reactive crisis management and, by necessity, would include anticipatory risk assessments. One avenue for doing so is being provided by simulation models that take advantage of the increase in computing capacity and performance that has occurred over the last two decades.
Here we review the literature to determine the state-of-the-art in modeling terrestrial protected areas under climate change, with the aim of evaluating and detecting trends and gaps in the current approaches being employed, as well as to provide a useful overview and guidelines for future research.
Results
Most studies apply statistical, bioclimatic envelope models and focus primarily on plant species as compared to other taxa. Very few studies utilize a mechanistic, process-based approach and none examine biotic interactions like predation and competition. Important factors like land-use, habitat fragmentation, invasion and dispersal are rarely incorporated, restricting the informative value of the resulting predictions considerably.
Conclusion
The general impression that emerges is that biodiversity conservation in protected areas could benefit from the application of modern modeling approaches to a greater extent than is currently reflected in the scientific literature. It is particularly true that existing models have been underutilized in testing different management options under climate change. Based on these findings we suggest a strategic framework for more effectively incorporating the impact of climate change in models exploring the effectiveness of protected areas.
Carbon (C) sequestration in soils plays a key role in the global C cycle. It is therefore crucial to adequately monitor dynamics in soil organic carbon (Delta SOC) stocks when aiming to reveal underlying processes and potential drivers. However, small-scale spatial (10-30 m) and temporal changes in SOC stocks, particularly pronounced in arable lands, are hard to assess. The main reasons for this are limitations of the well-established methods. On the one hand, repeated soil inventories, often used in long-term field trials, reveal spatial patterns and trends in Delta SOC but require a longer observation period and a sufficient number of repetitions. On the other hand, eddy covariance measurements of C fluxes towards a complete C budget of the soil-plant-atmosphere system may help to obtain temporal Delta SOC patterns but lack small-scale spatial resolution.
To overcome these limitations, this study presents a reliable method to detect both short-term temporal dynamics as well as small-scale spatial differences of Delta SOC using measurements of the net ecosystem carbon balance (NECB) as a proxy. To estimate the NECB, a combination of automatic chamber (AC) measurements of CO2 exchange and empirically modeled aboveground biomass development (NPPshoot / were used. To verify our method, results were compared with Delta SOC observed by soil resampling.
Soil resampling and AC measurements were performed from 2010 to 2014 at a colluvial depression located in the hummocky ground moraine landscape of northeastern Germany. The measurement site is characterized by a variable groundwater level (GWL) and pronounced small-scale spatial heterogeneity regarding SOC and nitrogen (Nt) stocks. Tendencies and magnitude of Delta SOC values derived by AC measurements and repeated soil inventories corresponded well. The period of maximum plant growth was identified as being most important for the development of spatial differences in annual Delta SOC. Hence, we were able to confirm that AC-based C budgets are able to reveal small-scale spatial differences and short-term temporal dynamics of Delta SOC.
For the first time a molecularly imprinted polymer (MIP)-based sensor for tyrosinase is described. This sensor is based on the electropolymerization of scopoletin or o-phenylenediamine in the presence of tyrosinase from mushrooms, which has a high homology to the human enzyme. The template was removed either by treatment with proteinase Kor by alkaline treatment. The measuring signal was generated either by measuring the formation of a product by the target enzyme or by evaluation of the permeability of the redox marker ferricyanide. The o-phenylenediamine-based MIP sensor has a linear measuring range up to 50 nM of tyrosinase with a limit of detection of 3.97 nM (R 2 = 0.994) and shows good discrimination towards other proteins, e.g., bovine serum albumin and cytochrome c.
With Saccharomyces cerevisiae being a commonly used host organism for synthetic biology and biotechnology approaches, the work presented here aims at the development of novel tools to improve and facilitate pathway engineering and heterologous protein production in yeast. Initially, the multi-part assembly strategy AssemblX was established, which allows the fast, user-friendly and highly efficient construction of up to 25 units, e.g. genes, into a single DNA construct. To speed up complex assembly projects, starting from sub-gene fragments and resulting in mini-chromosome sized constructs, AssemblX follows a level-based approach: Level 0 stands for the assembly of genes from multiple sub-gene fragments; Level 1 for the combination of up to five Level 0 units into one Level 1 module; Level 2 for linkages of up to five Level 1 modules into one Level 2 module. This way, all Level 0 and subsequently all Level 1 assemblies can be carried out simultaneously. Individually planned, overlap-based Level 0 assemblies enable scar-free and sequence-independent assemblies of transcriptional units, without limitations in fragment number, size or content. Level 1 and Level 2 assemblies, which are carried out via predefined, computationally optimized homology regions, follow a standardized, highly efficient and PCR-free scheme. AssemblX follows a virtually sequence-independent scheme with no need for time-consuming domestication of assembly parts. To minimize the risk of human error and to facilitate the planning of assembly projects, especially for individually designed Level 0 constructs, the whole AssemblX process is accompanied by a user-friendly webtool. This webtool provides the user with an easy-to-use operating surface and returns a bench-protocol including all cloning steps. The efficiency of the assembly process is further boosted through the implementation of different features, e.g. ccdB counter selection and marker switching/reconstitution. Due to the design of homology regions and vector backbones the user can flexibly choose between various overlap-based cloning methods, enabling cost-efficient assemblies which can be carried out either in E. coli or yeast. Protein production in yeast is additionally supported by a characterized library of 40 constitutive promoters, fully integrated into the AssemblX toolbox. This provides the user with a starting point for protein balancing and pathway engineering. Furthermore, the final assembly cassette can be subcloned into any vector, giving the user the flexibility to transfer the individual construct into any host organism different from yeast.
As successful production of heterologous compounds generally requires a precise adjustment of protein levels or even manipulation of the host genome to e.g. inhibit unwanted feedback regulations, the optogenetic transcriptional regulation tool PhiReX was designed. In recent years, light induction was reported to enable easy, reversible, fast, non-toxic and nearly gratuitous regulation, thereby providing manifold advantages compared to conventional chemical inducers. The optogenetic interface established in this study is based on the photoreceptor PhyB and its interacting protein PIF3. Both proteins, derived from Arabidopsis thaliana, dimerize in a red/far-red light-responsive manner. This interaction depends on a chromophore, naturally not available in yeast. By fusing split proteins to both components of the optical dimerizer, active enzymes can be reconstituted in a light-dependent manner. For the construction of the red/far-red light sensing gene expression system PhiReX, a customizable synTALE-DNA binding domain was fused to PhyB, and a VP64 activation domain to PIF3. The synTALE-based transcription factor allows programmable targeting of any desired promoter region. The first, plasmid-based PhiReX version mediates chromophore- and light-dependent expression of the reporter gene, but required further optimization regarding its robustness, basal expression and maximum output. This was achieved by genome-integration of the optical regulator pair, by cloning the reporter cassette on a high-copy plasmid and by additional molecular modifications of the fusion proteins regarding their cellular localization. In combination, this results in a robust and efficient activation of cells over an incubation time of at least 48 h. Finally, to boost the potential of PhiReX for biotechnological applications, yeast was engineered to produce the chromophore. This overcomes the need to supply the expensive and photo-labile compound exogenously. The expression output mediated through PhiReX is comparable to the strong constitutive yeast TDH3 promoter and - in the experiments described here - clearly exceeds the commonly used galactose inducible GAL1 promoter.
The fast-developing field of synthetic biology enables the construction of complete synthetic genomes. The upcoming Synthetic Yeast Sc2.0 Project is currently underway to redesign and synthesize the S. cerevisiae genome. As a prerequisite for the so-called “SCRaMbLE” system, all Sc2.0 chromosomes incorporate symmetrical target sites for Cre recombinase (loxPsym sites), enabling rearrangement of the yeast genome after induction of Cre with the toxic hormonal substance beta-estradiol. To overcome the safety concern linked to the use of beta-estradiol, a red light-inducible Cre recombinase, dubbed L-SCRaMbLE, was established in this study. L-SCRaMbLE was demonstrated to allow a time- and chromophore-dependent recombination with reliable off-states when applied to a plasmid containing four genes of the beta-carotene pathway, each flanked with loxPsym sites. When directly compared to the original induction system, L-SCRaMbLE generates a larger variety of recombination events and lower basal activity. In conclusion, L-SCRaMbLE provides a promising and powerful tool for genome rearrangement.
The three tools developed in this study provide so far unmatched possibilities to tackle complex synthetic biology projects in yeast by addressing three different stages: fast and reliable biosynthetic pathway assembly; highly specific, orthogonal gene regulation; and tightly controlled synthetic evolution of loxPsym-containing DNA constructs.
Plant cells host two important organelles: mitochondria, known as the cell’s ‘powerhouse’, which act by converting oxygen and nutrients into ATP, and plastids, which perform photosynthesis. These organelles contain their own genomes that encode proteins required for gene expression and energy metabolism. Transformation technologies offer great potential for investigating all aspects of the physiology and gene expression of these organelles in vivo. In addition, organelle transformation can be a valuable tool for biotechnology and molecular plant breeding. Plastid transformation systems are well-developed for a few higher plants, however, mitochondrial transformation has so far only been reported for Saccharomyces cerevisiae and the unicellular alga Chlamydomonas reinhardtii.
Development of an efficient new selection marker for plastid transformation is important for several reasons, including facilitating supertransformation of the plastid genome for metabolic engineering purposes and for producing multiple knock-outs or site-directed mutagenesis of two unlinked genes. In this work, we developed a novel selection system for Nicotiana tabacum (tobacco) chloroplast transformation with an alternative marker. The marker gene, aac(6′)-Ie/aph(2′′)-Ia, was cloned into different plastid transformation vectors and several candidate aminoglycoside antibiotics were investigated as selection agents. Generally, the efficiency of selection and the transformation efficiency with aac(6′)-Ie/aph(2′′)-Ia as selectable marker in combination with the aminoglycoside antibiotic tobramycin was similarly high as that with the standard marker gene aadA and spectinomycin selection. Furthermore, our new selection system may be useful for the development of plastid transformation for new species, including cereals, the world’s most important food crops, and could also be helpful for the establishment of a selection system for mitochondrial transformation.
To date, all attempts to achieve mitochondrial transformation for higher plants have been unsuccessful. A mitochondrial transformation system for higher plants would not only provide a potential for studying mitochondrial physiology but could also provide a method to introduce cytoplasmic male sterility into crops to produce hybrid seeds. Establishing a stable mitochondrial transformation system in higher plants requires several steps including delivery of foreign DNA, stable integration of the foreign sequences into the mitochondrial genome, efficient expression of the transgene, a highly regenerable tissue culture system that allows regeneration of the transformed cells into plants, and finally, a suitable selection system to identify cells with transformed mitochondrial genomes. Among all these requirements, finding a good selection is perhaps the most important obstacle towards the development of a mitochondrial transformation system for higher plants. In this work, two selection systems were tested for mitochondrial transformation: kanamycin as a selection system in combination with the antibiotic-inactivating marker gene nptII, and sulfadiazine as a selection agent that inhibits the folic acid biosynthesis pathway residing in plant mitochondria in combination with the sul gene encoding an enzyme that is insensitive to inhibition by sulfadiazine. Nuclear transformation experiments were considered as proof of the specificity of the sulfadiazine selection system for mitochondria. We showed that an optimized sulfadiazine selection system, with the Sul protein targeted to mitochondria, is much more efficient than the previous sulfadiazine selection system, in which the Sul protein was targeted to the chloroplast. We also showed by systematic experiments that the efficiency of selection and nuclear transformation of the optimized sulfadiazine selection was higher compared to the standard kanamycin selection system. Finally, we also investigated the suitability of this selection system for nuclear transformation of the model alga Chlamydomonas reinhardtii, obtaining promising results. Although we designed several mitochondrial transformation vectors with different expression elements and integration sites in the mitochondrial genome based on the sulfadiazine system, and different tissue culture condition were also considered, we were not able to obtain mitochondrial transformation with this system. Nonetheless, establishing the sul gene as an efficient and specific selection marker for mitochondria addresses one of the major bottlenecks and may pave the way to achieve mitochondrial transformation in higher plants.
We studied the short- (12 h) and long-term (144 h) response of Daphnia pulex lipases to quality shifts in diets consisting of different mixtures of the green alga Scenedesmus with the cyanobacterium Synechococcus, two species with contrasting lipid compositions. The lipase/esterase activity in both the gut and the body tissues had fast responses to the diet shift and increased with higher dietary contributions of Synechococcus. When screening the Daphnia genome for TAG lipases, we discovered a large gene-family expansion of these enzymes. We used a subset of eight genes for mRNA expression analyses and distinguished between influences of time and diet on the observed gene expression patterns. We identified five diet-responsive lipases of which three showed a sophisticated short- and long-term pattern of expression in response to small changes in food-quality. Furthermore, the gene expression of one of the lipases was strongly correlated to lipase/esterase activity in the gut suggesting its potentially major role in digestion. These findings demonstrate that the lipid-related enzymatic machinery of D. pulex is finely tuned to diet and might constitute an important mechanism of physiological adaptation in nutritionally complex environments.
We studied the short- (12 h) and long-term (144 h) response of Daphnia pulex lipases to quality shifts in diets consisting of different mixtures of the green alga Scenedesmus with the cyanobacterium Synechococcus, two species with contrasting lipid compositions. The lipase/esterase activity in both the gut and the body tissues had fast responses to the diet shift and increased with higher dietary contributions of Synechococcus. When screening the Daphnia genome for TAG lipases, we discovered a large gene-family expansion of these enzymes. We used a subset of eight genes for mRNA expression analyses and distinguished between influences of time and diet on the observed gene expression patterns. We identified five diet-responsive lipases of which three showed a sophisticated short- and long-term pattern of expression in response to small changes in food-quality. Furthermore, the gene expression of one of the lipases was strongly correlated to lipase/esterase activity in the gut suggesting its potentially major role in digestion. These findings demonstrate that the lipid-related enzymatic machinery of D. pulex is finely tuned to diet and might constitute an important mechanism of physiological adaptation in nutritionally complex environments.
We report on a study in which plasmid DNA in water was irradiated with 30 keV electrons generated by a scanning electron microscope and passed through a 100 nm thick Si3N4 membrane. The corresponding Monte Carlo simulations suggest that the kinetic energy spectrum of the electrons throughout the water is dominated by low energy electrons (<100 eV). The DNA radiation damage, single-strand breaks (SSBs) and double-strand breaks (DSBs), was determined by gel electrophoresis. The median lethal dose of D-1/2 = 1.7 +/- 0.3 Gy was found to be much smaller as compared to partially or fully hydrated DNA irradiated under vacuum conditions. The ratio of the DSBs to SSBs was found to be 1 : 12 as compared to 1 : 88 found for hydrated DNA. Our method enables quantitative measurements of radiation damage to biomolecules (DNA, proteins) in solutions under varying conditions (pH, salinity, co-solutes) for an electron energy range which is difficult to probe by standard methods.
Die Hybridomtechnik zur Produktion von monoklonalen Antikörpern ermöglichte einen großen Schritt in der Entwicklung von Immunoassays für die biochemische Forschung und klinische Diagnostik. Auch die Produktion von Antikörpern gegen niedermolekulare Analyten, Haptene, typische Targets in der Lebensmittel- und Umweltanalytik, erlangte in den letzten Jahren eine immer größere Bedeutung. Im Zuge der Durchführung der Hybridomtechnik werden tausende Antikörper-sezernierende und nicht-sezernierende Zellen generiert. Die Selektion der wenigen antigenselektiven Hybridomzellen zählt dabei zu den herausforderndsten Schritten für die Antikörpergewinnung. Bisherige Selektionsverfahren, wie die Limiting-Dilution-Klonierung in Verbindung mit Enzyme-linked Immunosorbent Assays (ELISAs), garantieren keine Monoklonalität und erlauben nur das Screening von einigen wenigen Zellklonen. Hingegen ermöglichen Hochdurchsatz-Selektionsmethoden, wie die Fluoreszenz-aktivierte Zellsortierung (FACS), einen sehr hohen Probendurchsatz. Eine Einzelzellablage garantiert hierbei Monoklonalität. Jedoch sind die dafür erforderlichen Zellmarkierungen oftmals zellschädigend oder aufwendig zu generieren. Auch ist bisher noch keine Markierungsmethode bekannt, die es ermöglicht, Hapten-selektive Hybridomzellen durchflusszytometrisch zu analysieren und eine FACS-Selektion durchzuführen.
Aus diesem Grund wurden in dieser Arbeit zwei Zellmarkierungsmethoden entwickelt, die dies ermöglichen sollten. Die membranständigen Antikörper von Hybridomzellen sollten entweder direkt oder indirekt immunfluoreszenz-markiert und dadurch für die Durchflusszytometrie und FACS-Selektion zugänglich gemacht werden. Die direkte Markierung wurde mittels eines Hapten-Fluorophor-Konjugats durchgeführt. Sie ermöglichte erstmalig den Anteil an Haptenselektiven Hybridomzellen in einer Hybridomzelllinie zu überprüfen. Dies konnte für zwei Hapten-selektive Hybridomzelllinien, die Antikörper gegen das Hormon 17β-Estradiol und das Cardenolid Digoxigenin bilden, gezeigt werden. Durchflusszytometrie und ELISAs lieferten vergleichbare Ergebnisse. Zellen, die Hapten-selektiv markiert werden konnten, sezernierten ebenfalls Hapten-selektive Antikörper. Des Weiteren konnte die direkte Markierung dazu genutzt werden, zwei Mykotoxin-selektive Hybridomzelllinien, welche Antikörper gegen Aflatoxin und Zearalenon bilden, auf Monoklonalität zu testen. Dies ist mittels ELISA nicht möglich. Die Markierungsmethode eignete sich jedoch nur für fixierte Hybridomzellen. Eine Markierung von lebenden Zellen konnte weder durchflusszytometrisch noch mittels konfokaler Laser-Scanning-Mikroskopie gezeigt werden.
Dies gelang erst mit einer neu entwickelten indirekten Immunfluoreszenzmarkierung. Dabei wurden die Zellen zunächst mit einem Hapten-Peroxidase-Konjugat inkubiert, gefolgt von einem Fluorophor-markierten anti-HRP-Antikörper-Konjugat. Dies wurde für zwei Analyten, das Hormon Estron und das Antiepileptikum Carbamazepin, gezeigt. Die indirekte Markierung wurde erfolgreich dazu verwendet, Carbamazepin-selektive Hybridomzellen aus einem Fusionsansatz für die monoklonale Antikörperproduktion auszusortieren. Damit wurde erstmalig eine Zellmarkierungsmethode entwickelt, die eine Hochdurchsatz-Selektion lebender Hybridomzellen aus einem Fusionsansatz ermöglicht. Sie ist nicht zellschädigend und kann zusätzlich zur Selektion Hapten-selektiver Plasmazellen verwendet werden.
Epigenetic maintenance of gene repression is essential for development. Polycomb complexes are central to this memory, but many aspects of the underlying mechanism remain unclear. LIKE HETEROCHROMATIN PROTEIN 1 (LHP1) binds Polycomb-deposited H3K27me3 and is required for repression of many Polycomb target genes in Arabidopsis. Here we show that LHP1 binds RNA in vitro through the intrinsically disordered hinge region. By independently perturbing the RNA-binding hinge region and H3K27me3 (trimethylation of histone H3 at Lys27) recognition, we found that both facilitate LHP1 localization and H3K27me3 maintenance. Disruption of the RNAbinding hinge region also prevented formation of subnuclear foci, structures potentially important for epigenetic repression.
Reproductive development of grapevine and berry composition are both strongly influenced by temperature. To date, the molecular mechanisms involved in grapevine berries response to high temperatures are poorly understood. Unlike recent data that addressed the effects on berry development of elevated temperatures applied at the whole plant level, the present work particularly focuses on the fruit responses triggered by direct exposure to heat treatment (HT). In the context of climate change, this work focusing on temperature effect at the microclimate level is of particular interest as it can help to better understand the consequences of leaf removal (a common viticultural practice) on berry development. HT (+8 degrees C) was locally applied to clusters from Cabernet Sauvignon fruiting cuttings at three different developmental stages (middle green, veraison and middle ripening). Samples were collected 1, 7, and 14 days after treatment and used for metabolic and transcriptomic analyses. The results showed dramatic and specific biochemical and transcriptomic changes in heat exposed berries, depending on the developmental stage and the stress duration. When applied at the herbaceous stage, HT delayed the onset of veraison. Heating also strongly altered the berry concentration of amino acids and organic acids (e.g., phenylalanine, raminobutyric acid and malate) and decreased the anthocyanin content at maturity. These physiological alterations could be partly explained by the deep remodeling of transcriptome in heated berries. More than 7000 genes were deregulated in at least one of the nine experimental conditions. The most affected processes belong to the categories "stress responses," protein metabolism" and "secondary metabolism," highlighting the intrinsic capacity of grape berries to perceive HT and to build adaptive responses. Additionally, important changes in processes related to "transport," "hormone" and "cell wall" might contribute to the postponing of veraison. Finally, opposite effects depending on heating duration were observed for genes encoding enzymes of the general phenylpropanoid pathway, suggesting that the HI induced decrease in anthocyanin content may result from a combination of transcript abundance and product degradation.
Aerobic anoxygenic phototrophs (AAPs) have been shown to exist in numerous marine and brackish environments where they are hypothesized to play important ecological roles. Despite their potential significance, the study of freshwater AAPs is in its infancy and limited to local investigations. Here, we explore the occurrence, diversity and distribution of AAPs in lakes covering a wide latitudinal gradient: Mongolian and German lakes located in temperate regions of Eurasia, tropical Great East African lakes, and polar permanently ice-covered Antarctic lakes. Our results show a widespread distribution of AAPs in lakes with contrasting environmental conditions and confirm that this group is composed of different members of the Alpha- and Betaproteobacteria. While latitude does not seem to strongly influence AAP abundance, clear patterns of community structure and composition along geographic regions were observed as indicated by a strong macro-geographical signal in the taxonomical composition of AAPs. Overall, our results suggest that the distribution patterns of freshwater AAPs are likely driven by a combination of small-scale environmental conditions (specific of each lake and region) and large-scale geographic factors (climatic regions across a latitudinal gradient).
The effects of biodiversity on ecosystem functioning generally increase over time, but the underlying processes remain unclear. Using 26 long-term grassland and forest experimental ecosystems, we demonstrate that biodiversity-ecosystem functioning relationships strengthen mainly by greater increases in functioning in high-diversity communities in grasslands and forests. In grasslands, biodiversity effects also strengthen due to decreases in functioning in low-diversity communities. Contrasting trends across grasslands are associated with differences in soil characteristics.
Do cities represent sources, sinks or isolated islands for urban wild boar population structure?
(2017)
ecoAO
(2017)
Although aldehyde oxidase (AO) is an important hepatic drug-metabolizing enzyme, it remains understudied and is consequently often overlooked in preclinical studies, an oversight that has resulted in the failure of multiple clinical trials. AO’s preclusion to investigation stems from the following: (1) difficulties synthesizing metabolic standards due to the chemospecificity and regiospecificity of the enzyme and (2) significant inherent variability across existing in vitro systems including liver cytosol, S9 fractions, and primary hepatocytes, which lack specificity and generate discordant expression and activity profiles. Here, we describe a practical bacterial biotransformation system, ecoAO, addressing both issues simultaneously. ecoAO is a cell paste of MoCo-producing Escherichia coli strain TP1017 expressing human AO. It exhibits specific activity toward known substrates, zoniporide, 4-trans-(N,N-dimethylamino)cinnamaldehyde, O6-benzylguanine, and zaleplon; it also has utility as a biocatalyst, yielding milligram quantities of synthetically challenging metabolite standards such as 2-oxo-zoniporide. Moreover, ecoAO enables routine determination of kcat and V/K, which are essential parameters for accurate in vivo clearance predictions. Furthermore, ecoAO has potential as a preclinical in vitro screening tool for AO activity, as demonstrated by its metabolism of 3-aminoquinoline, a previously uncharacterized substrate. ecoAO promises to provide easy access to metabolites with the potential to improve pharmacokinetic clearance predictions and guide drug development.
Mixing events in stratified lakes result in microalgae being exposed to varying conditions in light and organic carbon concentrations. Stratified lakes consist of an upper illuminated strata and a lower, darker strata where organic carbon accumulates. Therefore, in this contribution we explore the importance of dissolved organic carbon for growth under various light intensities by measuring some ecophysiological adaptations in two green microalgae. We compared the non-motile Chlorella vulgaris with the flagellated Chlamydomonas acidophila under auto-, mixo-, and heterotrophic growth conditions. In both algae the maximum photosynthetic and growth rates were highest under mixotrophy, and both algae appeared inhibited in their phosphorus acquisition under heterotrophy. Heterotrophic conditions provoked the largest differences as C. vulgaris produced chlorophyll a in darkness and grew as well as in autotrophic conditions, whereas Chl. acidophila bleached and could not grow heterotrophically. Although the fatty acid composition of both phytoplankton species differed, both species reacted in a similar way to changes in their growth conditions, mainly by a decrease of C18:3n-3 and an increase of C18:1n-9 from auto- to heterotrophic conditions. The two contrasting responses within the group of green microalgae suggest that dissolved organic carbon has a high deterministic potential to explain the survival and behaviour of green algae in the deeper strata of lakes.
EDTA and NTA effectively tune the mineralization of calcium phosphate from bulk aqueous solution
(2017)
This study describes the effects of nitrilotriacetic acid (NTA) and ethylenediaminotetraacetic acid (EDTA) on themineralization of calciumphosphate from bulk aqueous solution. Mineralization was performed between pH 6 and 9 and with NTA or EDTA concentrations of 0, 5, 10, and 15 mM. X-ray diffraction and infrared spectroscopy show that at low pH, mainly brushite precipitates and at higher pH, mostly hydroxyapatite forms. Both additives alter the morphology of the precipitates. Without additive, brushite precipitates as large plates. With NTA, the morphology changes to an unusual rod-like shape. With EDTA, the edges of the particles are rounded and disk-like particles form. Conductivity and pH measurements suggest that the final products form through several intermediate steps.
Core-specific sensorimotor exercises are proven to enhance neuromuscular activity of the trunk. However, the influence of high-intensity perturbations on training efficiency is unclear within this context. Sixteen participants (29 +/- 2 yrs; 175 +/- 8 cm; 69 +/- 13 kg) were prepared with a 12-lead bilateral trunk EMG. Warm-up on a dynamometer was followed by maximum voluntary isometric trunk (flex/ext) contraction (MVC). Next, participants performed four conditions for a one-legged stance with hip abduction on a stable surface (HA) repeated randomly on an unstable surface (HAP), on a stable surface with perturbation (HA + P), and on an unstable surface with perturbation (HAP + P). Afterwards, bird dog (BD) was performed under the same conditions (BD, BDP, BD + P, BDP + P). A foam pad under the foot (HA) or the knee (BD) was used as an unstable surface. Exercises were conducted on a moveable platform. Perturbations (ACC 50 m/sec(2);100 ms duration;10rep.) were randomly applied in the anterior-posterior direction. The root mean square (RMS) normalized to MVC (%) was calculated (whole movement cycle). Muscles were grouped into ventral right and left (VR;VL), and dorsal right and left (DR;DL). Ventral Dorsal and right-left ratios were calculated (two way repeated-measures ANOVA;alpha = 0,05). Amplitudes of all muscle groups in bird dog were higher compared to hip abduction (p <= 0.0001; Range: BD: 14 +/- 3% (BD;VR) to 53 +/- 4%; HA: 7 +/- 2% (HA;DR) to 16 +/- 4% (HA;DR)). EMG-RMS showed significant differences (p < 0.001) between conditions and muscle groups per exercise. Interaction effects were only significant for HA (p = 0.02). No significant differences were present in EMG ratios (p > 0.05). Additional high-intensity perturbations during core-specific sensorimotor exercises lead to increased neuromuscular activity and therefore higher exercise intensities. However, the beneficial effects on trunk function remain unclear. Nevertheless, BD is more suitable to address trunk muscles.
This is a cumulative dissertation comprising three original studies (one published, one in revision, one submitted; Effective December 2017) investigating how reptile species in arid Australia respond to various climatic parameters at different spatial scales and analysing the two potential main underlying mechanisms: thermoregulatory behaviour and species interactions. This dissertation combines extensive individual-based field data across trophic levels, selected field experiments, statistical analyses, and predictive modelling techniques. Mechanisms and processes detected in this dissertation can now be used to predict potential future changes in the community of arid-zone lizards. This knowledge will help improving our fundamental understanding of the consequences of global change and thereby prevent biodiversity loss in a vulnerable ecosystem.
In mormyrid weakly electric fish, the electric organ discharge (EOD) is used for species recognition, orientation and prey localization. Produced in the muscle-derived adult electric organ, the EOD exhibits a wide diversity across species in both waveform and duration. While certain defining EOD characteristics can be linked to anatomical features of the electric organ, many factors underlying EOD differentiation are yet unknown. Here, we report the differential expression of 13 Kv1 voltage-gated potassium channel genes, two inwardly rectifying potassium channel genes, two previously studied sodium channel genes and an ATPase pump in two sympatric species of the genus Campylomormyrus in both the adult electric organ and skeletal muscle. Campylomormyrus compressirostris displays a basal EOD, largely unchanged during development, while C. tshokwe has an elongated, putatively derived discharge. We report an upregulation in all Kv1 genes in the electric organ of Campylomormyrus tshokwe when compared to both skeletal muscle and C. compressirostris electric organ. This pattern of upregulation in a species with a derived EOD form suggests that voltage-gated potassium channels are potentially involved in the diversification of the EOD signal among mormyrid weakly electric fish.
Lying is an everyday moral phenomenon about which philosophers have written a lot. Not only the moral status of lying has been intensively discussed but also what it means to lie in the first place. Perhaps the most important criterion for an adequate definition of lying is that it fits with people’s understanding and use of this concept. In this light, it comes as a surprise that researchers only recently started to empirically investigate the folk concept of lying. In this paper, we describe three experimental studies which address the following questions: Does a statement need to be objectively false in order to constitute lying? Does lying necessarily include the intention to deceive? Can one lie by omitting relevant facts?
Natural products and their derivatives have always been a source of drug leads. In particular, bacterial compounds have played an important role in drug development, for example in the field of antibiotics. A decrease in the discovery of novel leads from natural sources and the hope of finding new leads through the generation of large libraries of drug-like compounds by combinatorial chemistry aimed at specific molecular targets drove the pharmaceutical companies away from research on natural products. However, recent technological advances in genetics, bioinformatics and analytical chemistry have revived the interest in natural products. The ribosomally synthesized and post-translationally modified peptides (RiPPs) are a group of natural products generated by the action of post-translationally modifying enzymes on precursor peptides translated from mRNA by ribosomes. The great substrate promiscuity exhibited by many of the enzymes from RiPP biosynthetic pathways have led to the generation of hundreds of novel synthetic and semisynthetic variants, including variants carrying non-canonical amino acids (ncAAs). The microviridins are a family of RiPPs characterized by their atypical tricyclic structure composed of lactone and lactam rings, and their activity as serine protease inhibitors. The generalities of their biosynthetic pathway have already been described, however, the lack of information on details such as the protease responsible for cleaving off the leader peptide from the cyclic core peptide has impeded the fast and cheap production of novel microviridin variants. In the present work, knowledge on leader peptide activation of enzymes from other RiPP families has been extrapolated to the microviridin family, making it possible to bypass the need of a leader peptide. This feature allowed for the exploitation of the microviridin biosynthetic machinery for the production of novel variants through the establishment of an efficient one-pot in vitro platform. The relevance of this chemoenzymatic approach has been exemplified by the synthesis of novel potent serine protease inhibitors from both rationally-designed peptide libraries and bioinformatically predicted microviridins. Additionally, new structure-activity relationships (SARs) could be inferred by screening microviridin intermediates. The significance of this technique was further demonstrated by the simple incorporation of ncAAs into the microviridin scaffold.
Recent advances in gene function prediction rely on ensemble approaches that integrate results from multiple inference methods to produce superior predictions. Yet, these developments remain largely unexplored in plants. We have explored and compared two methods to integrate 10 gene co-function networks for Arabidopsis thaliana and demonstrate how the integration of these networks produces more accurate gene function predictions for a larger fraction of genes with unknown function. These predictions were used to identify genes involved in mitochondrial complex I formation, and for five of them, we confirmed the predictions experimentally. The ensemble predictions are provided as a user-friendly online database, EnsembleNet. The methods presented here demonstrate that ensemble gene function prediction is a powerful method to boost prediction performance, whereas the EnsembleNet database provides a cutting-edge community tool to guide experimentalists.
Spatial environmental heterogeneity is considered a fundamental factor for the maintenance of plant species richness. However, it still remains unclear whether heterogeneity may also facilitate coexistence at fine grain sizes or whether other processes, like mass effects and source sink dynamics due to dispersal, control species composition and diversity at these scales. In this study, we used two complimentary analyses to identify the role of heterogeneity within 15 m x 15 m plots for the coexistence of species-rich annual communities in a semi-arid environment along a steep precipitation gradient. Specifically, we: (a) analyzed the effect of environmental heterogeneity on species, functional and phylogenetic diversity within microsites (alpha diversity, 0.06 m(2) and 1 m(2)), across microsites (beta diversity), and diversity at the entire plot (gamma diversity); (b) further we used two null models to detect non-random trait and phylogenetic patterns in order to infer assembly processes, i.e. whether co-occurring species tend to share similar traits (trait convergence) or dissimilar traits (trait divergence). In general, our results showed that heterogeneity had a positive effect on community diversity. Specifically, for alpha diversity, the effect was significant for functional diversity, and not significant for either species or phylogenetic diversities. For beta diversity, all three measures of community diversity (species, functional, and phylogenetic) increased significantly, as they also did for gamma diversity, where functional measures were again stronger than for species or phylogenetic measures. In addition, the null model approach consistently detected trait convergence, indicating that species with similar traits tended to co-occur and had high abundances in a given microsite. While null model analysis across the phylogeny partly supported these trait findings, showing phylogenetic underdispersion at the 1m(2) grain size, surprisingly when species abundances in microsites were analyzed they were more evenly distributed across the phylogenetic tress than expected (phylogenetic overdispersion). In conclusion, our results provide compelling support that environmental heterogeneity at a relatively fine scale is an important factor for species co-existence as it positively affects diversity as well as influences species assembly. Our study underlines the need for trait-based approaches conducted at fine grain sizes in order to better understand species coexistence and community assembly. (C) 2017 Elsevier GmbH. All rights reserved.
Enzymes from the xanthine oxidase (XO) family of molybdenum enzymes are generally, with some exceptions, molybdenum iron–sulfur flavin hydroxylases. Mammalian xanthine oxidoreductase and aldehyde oxidase were among the first enzymes to be studied in detail more than 100 years ago and, surprisingly, they continue to be thoroughly studied in molecular detail with many open and unresolved questions remaining. Enzymes of the XO family are characterized by a molybdenum cofactor (Moco) active site with a MoVIOS(OH) ligand sphere where substrate hydroxylation of either aromatic or aliphatic carbon centers is catalyzed. During the reaction, electrons are transferred to the oxidizing substrate, most commonly O2 or NAD+, which react at the FAD site.
Plants frequently have to weather both biotic and abiotic stressors, and have evolved sophisticated adaptation and defense mechanisms. In recent years, chromatin modifications, nucleosome positioning, and DNA methylation have been recognized as important components in these adaptations. Given their potential epigenetic nature, such modifications may provide a mechanistic basis for a stress memory, enabling plants to respond more efficiently to recurring stress or even to prepare their offspring for potential future assaults. In this review, we discuss both the involvement of chromatin in stress responses and the current evidence on somatic, intergenerational, and transgenerational stress memory.
Exploring the Arabidopsis metabolic landscape by genetic mapping integrated with network analysis
(2017)
Motivated by conflicting evidence in the literature, we re-assessed the role of facial feedback when detecting quantitative or qualitative changes in others’ emotional expressions. Fifty-three healthy adults observed self-paced morph sequences where the emotional facial expression either changed quantitatively (i.e., sad-to-neutral, neutral-to-sad, happy-to-neutral, neutral-to-happy) or qualitatively (i.e. from sad to happy, or from happy to sad). Observers held a pen in their own mouth to induce smiling or frowning during the detection task. When morph sequences started or ended with neutral expressions we replicated a congruency effect: Happiness was perceived longer and sooner while smiling; sadness was perceived longer and sooner while frowning. Interestingly, no such congruency effects occurred for transitions between emotional expressions. These results suggest that facial feedback is especially useful when evaluating the intensity of a facial expression, but less so when we have to recognize which emotion our counterpart is expressing.
To study the role of the TTR-RBP4-ROH complex components (transthyretin, serum retinol binding protein, retinol) and of angiogenic factors PlGF (placental growth factor) and sFlt-1 (soluble fms-like tyrosine kinase-1) in pregnancies complicated by small for gestational age infants (SGA). Case control study conducted on maternal serum collected between 11 + 0 to 13 + 6 weeks of gestation. TTR, RBP4, ROH, PlGF and sFlt-1 were measured in SGA patients (birth weight < 10%) who delivered at term (n = 37) and before 37 weeks of gestation (n = 17) and in a matched control group with uneventful pregnancies (n = 37). We found decreased RBP4 in SGA patients that delivered fetuses < 3% and in fetuses delivered after the 37 weeks of gestation compared to controls [1.50 (95% CI 1.40-1.75) vs 1.62 (95% CI 1.47-1.98), p < 0.05]. Further, we found lower PlGF and sFlt-1 concentrations in SGA that delivered before 37 weeks of gestation compared to controls (respectively, PIGF and sFlt-1: 39.7 pg/ml (95% CI 32.3-66.3) vs 62.9 pg/ml (95% CI 45.2-78.4) and 906 pg/ml (95% CI 727-1626) vs 1610 pg/ml (95% CI 1088-212), p < 0.05). First trimester maternal serum RBP4 and angiogenic factors PlGF and sFlt-1 can differently predict the timing of delivery of pregnancies complicated by SGA fetuses.
Fat loads were quantified for 2125 Yellow-browed Warblers Phylloscopus inornatus trapped at a stop-over site in Far East Russia during autumn migration. Flight ranges of 660-820km were estimated for the fattest individuals, suggesting that they would need to stop for refuelling at least six times to reach their wintering areas in South East Asia.
Late embryogenesis abundant (LEA) proteins are related to cellular dehydration tolerance. Most LEA proteins are predicted to have no stable secondary structure in solution, i.e., to be intrinsically disordered proteins (IDPs), but they may acquire alpha-helical structure upon drying. In the model plant Arabidopsis thaliana, the LEA proteins COR15A and COR15B are highly induced upon cold treatment and are necessary for the plants to attain full freezing tolerance. Freezing leads to increased intracellular crowding due to dehydration by extracellular ice crystals. In vitro, crowding by high glycerol concentrations induced partial folding of COR15 proteins. Here, we have extended these investigations to two related proteins, LEA11 and LEA25. LEA25 is much longer than LEA11 and COR15A, but shares a conserved central sequence domain with the other two proteins. We have created two truncated versions of LEA25 (2H and 4H) to elucidate the structural and functional significance of this domain. Light scattering and CD spectroscopy showed that all five proteins were largely unstructured and monomeric in dilute solution. They folded in the presence of increasing concentrations of trifluoroethanol and glycerol. Additional folding was observed in the presence of glycerol and membranes. Fourier transform infra red spectroscopy revealed an interaction of the LEA proteins with membranes in the dry state leading to a depression in the gel to liquid-crystalline phase transition temperature. Liposome stability assays revealed a cryoprotective function of the proteins. The C- and N-terminal extensions of LEA25 were important in cryoprotection, as the central domain itself (2H, 4H) only provided a low level of protection.
Background: Although nowaday it is broadly accepted that mitochondrial DNA (mtDNA) may undergo recombination, the frequency of such recombination remains controversial. Its estimation is not straightforward, as recombination under homoplasmy (i.e., among identical mt genomes) is likely to be overlooked. In species with tandem duplications of large mtDNA fragments the detection of recombination can be facilitated, as it can lead to gene conversion among duplicates. Although the mechanisms for concerted evolution in mtDNA are not fully understood yet, recombination rates have been estimated from "one per speciation event" down to 850 years or even "during every replication cycle".
Results: Here we present the first complete mt genome of the avian family Bucerotidae, i.e., that of two Philippine hornbills, Aceros waldeni and Penelopides panini. The mt genomes are characterized by a tandemly duplicated region encompassing part of cytochrome b, 3 tRNAs, NADH6, and the control region. The duplicated fragments are identical to each other except for a short section in domain I and for the length of repeat motifs in domain III of the control region. Due to the heteroplasmy with regard to the number of these repeat motifs, there is some size variation in both genomes; with around 21,657 bp (A. waldeni) and 22,737 bp (P. panini), they significantly exceed the hitherto longest known avian mt genomes, that of the albatrosses. We discovered concerted evolution between the duplicated fragments within individuals. The existence of differences between individuals in coding genes as well as in the control region, which are maintained between duplicates, indicates that recombination apparently occurs frequently, i. e., in every generation.
Conclusions: The homogenised duplicates are interspersed by a short fragment which shows no sign of recombination. We hypothesize that this region corresponds to the so-called Replication Fork Barrier (RFB), which has been described from the chicken mitochondrial genome. As this RFB is supposed to halt replication, it offers a potential mechanistic explanation for frequent recombination in mitochondrial genomes.
Single molecule RNA fluorescent in situ hybridization (smFISH) enables gene transcription to be assessed at the cellular level. In this point of view article, we describe our recent smFISH research in the model plant Arabidopsis thaliana and discuss how this technique could further knowledge of plant gene transcription in the future.
Monoclonal antibodies are universal binding molecules and are widely used in biomedicine and research. Nevertheless, the generation of these binding molecules is time-consuming and laborious due to the complicated handling and lack of alternatives. The aim of this protocol is to provide one standard method for the generation of monoclonal antibodies using hybridoma technology. This technology combines two steps. Step 1 is an appropriate immunization of the animal and step 2 is the fusion of B lymphocytes with immortal myeloma cells in order to generate hybrids possessing both parental functions, such as the production of antibody molecules and immortality. The generated hybridoma cells were then recloned and diluted to obtain stable monoclonal cell cultures secreting the desired monoclonal antibody in the culture supernatant. The supernatants were tested in enzyme-linked immunosorbent assays (ELISA) for antigen specificity. After the selection of appropriate cell clones, the cells were transferred to mass cultivation in order to produce the desired antibody molecule in large amounts. The purification of the antibodies is routinely performed by affinity chromatography. After purification, the antibody molecule can be characterized and validated for the final test application. The whole process takes 8 to 12 months of development, and there is a high risk that the antibody will not work in the desired test system.
The Leopard cat Prionailurus bengalensis is a habitat generalist that is widely distributed across Southeast Asia. Based on morphological traits, this species has been subdivided into 12 subspecies. Thus far, there have been few molecular studies investigating intraspecific variation, and those had been limited in geographic scope. For this reason, we aimed to study the genetic structure and evolutionary history of this species across its very large distribution range in Asia. We employed both PCR-based (short mtDNA fragments, 94 samples) and high throughput sequencing based methods (whole mitochondrial genomes, 52 samples) on archival, noninvasively collected and fresh samples to investigate the distribution of intraspecific genetic variation. Our comprehensive sampling coupled with the improved resolution of a mitochondrial genome analyses provided strong support for a deep split between Mainland and Sundaic Leopard cats. Although we identified multiple haplogroups within the species’ distribution, we found no matrilineal evidence for the distinction of 12 subspecies. In the context of Leopard cat biogeography, we cautiously recommend a revision of the Prionailurus bengalensis subspecific taxonomy: namely, a reduction to 4 subspecies (2 mainland and 2 Sundaic forms).
Genome-wide association studies of birth weight have focused on fetal genetics, whereas relatively little is known about the role of maternal genetic variation. We aimed to identify maternal genetic variants associated with birth weight that could highlight potentially relevant maternal determinants of fetal growth. We meta-analysed data on up to 8.7 million SNPs in up to 86 577 women of European descent from the Early Growth Genetics (EGG) Consortium and the UK Biobank. We used structural equation modelling (SEM) and analyses of mother–child pairs to quantify the separate maternal and fetal genetic effects. Maternal SNPs at 10 loci (MTNR1B, HMGA2, SH2B3, KCNAB1, L3MBTL3, GCK, EBF1, TCF7L2, ACTL9, CYP3A7) were associated with offspring birth weight at P < 5 Â 10 À8 . In SEM analyses, at least 7 of the 10 associations were consistent with effects of the maternal genotype acting via the intrauterine environment, rather than via effects of shared alleles with the fetus. Variants, or correlated proxies, at many of the loci had been previously associated with adult traits, including fasting glucose (MTNR1B, GCK and TCF7L2) and sex hormone levels (CYP3A7), and one (EBF1) with gestational duration. The identified associations indicate that genetic effects on maternal glucose, cytochrome P450 activity and gestational duration, and potentially on maternal blood pressure and immune function, are relevant for fetal growth. Further characterization of these associations in mechanistic and causal analyses will enhance understanding of the potentially modifiable maternal determinants of fetal growth, with the goal of reducing the morbidity and mortality associated with low and high birth weights.
Global effects of income and income inequality on adult height and sexual dimorphism in height
(2017)
Objectives: Average adult height of a population is considered a biomarker of the quality of the health environment and economic conditions. The causal relationships between height and income inequality are not well understood. We analyze data from 169 countries for national average heights of men and women and national-level economic factors to test two hypotheses: (1) income inequality has a greater association with average adult height than does absolute income; and (2) neither income nor income inequality has an effect on sexual dimorphism in height. Methods: Average height data come from the NCD-RisC health risk factor collaboration. Economic indicators are derived from the World Bank data archive and include gross domestic product (GDP), Gross National Income per capita adjusted for personal purchasing power (GNI_ PPP), and income equality assessed by the Gini coefficient calculated by the Wagstaff method. Results: Hypothesis 1 is supported. Greater income equality is most predictive of average height for both sexes. GNI_ PPP explains a significant, but smaller, amount of the variation. National GDP has no association with height. Hypothesis 2 is rejected. With greater average adult height there is greater sexual dimorphism. Conclusions: Findings support a growing literature on the pernicious effects of inequality on growth in height and, by extension, on health. Gradients in height reflect gradients in social disadvantage. Inequality should be considered a pollutant that disempowers people from the resources needed for their own healthy growth and development and for the health and good growth of their children.
A synthetic protocol for the fabrication of ultrathin polymeric films containing the enzyme 2-deoxy-D-ribose-5-phosphate aldolase from Escherichia coli (DERA(EC)) is presented. Ultrathin enzymatically active films are useful for applications in which only small quantities of active material are needed and at the same time quick response and contact times without diffusion limitation are wanted. We show how DERA as an exemplary enzyme can be immobilized in a thin polymer layer at the air-water interface and transferred to a suitable support by the Langmuir-Schaefer technique under full conservation of enzymatic activity. The polymer in use is a poly(N-isopropylacrylamide-co-N-2-thiolactone acrylamide) (P(NIPAAm-co-TlaAm)) statistical copolymer in which the thiolactone units serve a multitude of purposes including hydrophobization of the polymer, covalent binding of the enzyme and the support and finally cross-linking of the polymer matrix. The application of this type of polymer keeps the whole approach simple as additional cocomponents such as cross-linkers are avoided.
Impact of normal weight obesity on fundamental motor skills in pre-school children aged 3 to 6 years
(2017)
Normal weight obesity is defined as having excessive body fat, but normal BMI. Even though previous research revealed that excessive body fat in children inhibited their physical activity and decreased motor performance, there has been only little evidence about motor performance of normal weight obese children. This study aims to establish whether normal weight obese pre-school children aged 3-6 years will have a significantly worse level of fundamental motor skills compared to normal weight non-obese counterparts. The research sample consisted of 152 pre-schoolers selected from a specific district of Prague, the Czech Republic. According to values from four skinfolds: triceps, subscapula, suprailiaca, calf, and BMI three categories of children aged 3-6 years were determined: A) normal weight obese n = 51; B) normal weight non-obese n = 52; C) overweight and obese n = 49. The Movement Assessment Battery for Children (MABC-2) was used for the assessment of fundamental motor skills. Normal weight obese children had significantly higher amount of adipose tissue p < 0.001 than normal weight non-obese children but the same average BMI. Moreover, normal weight obese children did not have significantly less amount of subcutaneous fat on triceps and calf compared to their overweight and obese peers. In majority of MABC-2 tests, normal weight obese pre-schoolers showed the poorest performance. Moreover, normal weight obese children had significantly worse total standard score = 38.82 compared to normal weight non-obese peers = 52.27; p < 0.05. In addition, normal weight obese children had a more than three times higher frequency OR = 3.69 CI95% (1.10; 12.35) of severe motor deficit performance <= 5th centile of the MABC-2 norm. These findings are strongly alarming since indices like BMI are not able to identify normal weight obese individual. We recommend verifying real portion of normal weight obese children as they are probably in higher risk of health and motor problems than overweight and obese population due to their low lean mass.
Import and decomposition of dissolved organic carbon in pre-dams of drinking water reservoirs
(2017)
Dissolved organic carbon (DOC) depicts a key component in the aquatic carbon cycle as well as for drinking water production from surface waters. DOC concentrations increased in water bodies of the northern hemisphere in the last decades, posing ecological consequences and water quality problems. Within the pelagic zone of lakes and reservoirs, the DOC pool is greatly affected by biological activity as DOC is simultaneously produced and decomposed. This thesis aimed for a conceptual understanding of organic carbon cycling and DOC quality changes under differing hydrological and trophic conditions. Further, the occurrence of aquatic priming was investigated, which has been proposed as a potential process facilitating the microbial decomposition of stable allochthonous DOC within the pelagic zone.
To study organic carbon cycling under different hydrological conditions, quantitative and qualitative investigations were carried out in three pre-dams of drinking water reservoirs exhibiting a gradient in DOC concentrations and trophic states. All pre-dams were mainly autotrophic in their epilimnia. Discharge and temperature were identified as the key factors regulating net production and respiration in the upper water layers of the pre-dams. Considerable high autochthonous production was observed during the summer season under higher trophic status and base flow conditions. Up to 30% of the total gained organic carbon was produced within the epilimnia. Consequently, this affected the DOC quality within the pre-dams over the year and enhanced characteristics of algae-derived DOC were observed during base flow in summer. Allochthonous derived DOC dominated at high discharges and oligotrophic conditions when production and respiration were low. These results underline that also small impoundments with typically low water residence times are hotspots of carbon cycling, significantly altering water quality in dependence of discharge conditions, temperature and trophic status. Further, it highlights that these factors need to be considered in future water management as increasing temperatures and altered precipitation patterns are predicted in the context of climate change.
Under base flow conditions, heterotrophic bacteria preferentially utilized older DOC components with a conventional radiocarbon age of 195-395 years before present (i.e. before 1950). In contrast, younger carbon components (modern, i.e. produced after 1950) were mineralized following a storm flow event. This highlights that age and recalcitrance of DOC are independent from each other. To assess the ages of the microbially consumed DOC, a simplified method was developed to recover the respired CO2 from heterotrophic bacterioplankton for carbon isotope analyses (13C, 14C). The advantages of the method comprise the operation of replicate incubations at in-situ temperatures using standard laboratory equipment and thus enabling an application in a broad range of conditions.
Aquatic priming was investigated in laboratory experiments during the microbial decomposition of two terrestrial DOC substrates (peat water and soil leachate). Thereby, natural phytoplankton served as a source of labile organic matter and the total DOC pool increased throughout the experiments due to exudation and cell lysis of the growing phytoplankton. A priming effect for both terrestrial DOC substrates was revealed via carbon isotope analysis and mixing models. Thereby, priming was more pronounced for the peat water than for the soil leachate. This indicates that the DOC source and the amount of the added labile organic matter might influence the magnitude of a priming effect. Additional analysis via high-resolution mass spectrometry revealed that oxidized, unsaturated compounds were more strongly decomposed under priming (i.e. in phytoplankton presence). Given the observed increase in DOC concentrations during the experiments, it can be concluded that aquatic priming is not easily detectable via net concentration changes alone and could be considered as a qualitative effect.
The knowledge gained from this thesis contributes to the understanding of aquatic carbon cycling and demonstrated how DOC dynamics in freshwaters vary with hydrological, seasonal and trophic conditions. It further demonstrated that aquatic priming contributes to the microbial transformation of organic carbon and the observed decay of allochthonous DOC during transport in inland waters.