TY - JOUR A1 - Meissner, Sven A1 - Steinhauser, Dirk A1 - Dittmann-Thünemann, Elke T1 - Metabolomic analysis indicates a pivotal role of the hepatotoxin microcystin in high light adaptation of Microcystis JF - Environmental microbiology N2 - Microcystis is a freshwater cyanobacterium frequently forming nuisance blooms in the summer months. The genus belongs to the predominant producers of the potent hepatotoxin microcystin. The success of Microcystis and its remarkable resistance to high light conditions are not well understood. Here, we have compared the metabolic response of Microcystis aeruginosaPCC7806, its microcystin-deficient mcyB mutant (Mut) and the cyanobacterial model organism SynechocystisPCC6803 to high light exposure of 250molphotonsm(-2)s(-1) using GC/MS-based metabolomics. Microcystis wild type and Mut show pronounced differences in their metabolic reprogramming upon high light. Seventeen percent of the detected metabolites showed significant differences between the two genotypes after high light exposure. Whereas the microcystin-producing wild type shows a faster accumulation of glycolate upon high light illumination, loss of microcystin leads to an accumulation of general stress markers such as trehalose and sucrose. The study further uncovers differences in the high light adaptation of the bloom-forming cyanobacterium Microcystis and the model cyanobacterium Synechocystis. Most notably, Microcystis invests more into carbon reserves such as glycogen after high light exposure. Our data shed new light on the lifestyle of bloom-forming cyanobacteria, the role of the widespread toxin microcystin and the metabolic diversity of cyanobacteria. Y1 - 2015 U6 - https://doi.org/10.1111/1462-2920.12565 SN - 1462-2912 SN - 1462-2920 VL - 17 IS - 5 SP - 1497 EP - 1509 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - McKenna, Shane M. A1 - Leimkühler, Silke A1 - Herter, Susanne A1 - Turner, Nicholas J. A1 - Carnell, Andrew J. T1 - Enzyme cascade reactions: synthesis of furandicarboxylic acid (FDCA) and carboxylic acids using oxidases in tandem JF - Green chemistry : an international journal and green chemistry resource N2 - A one-pot tandem enzyme reaction using galactose oxidase M3-5 and aldehyde oxidase PaoABC was used to convert hydroxymethylfurfural (HMF) to the pure bioplastics precursor FDCA in 74% isolated yield. A range of alcohols was also converted to carboxylic acids in high yield under mild conditions. Y1 - 2015 U6 - https://doi.org/10.1039/c5gc00707k SN - 1463-9262 SN - 1463-9270 VL - 17 IS - 6 SP - 3271 EP - 3275 PB - Royal Society of Chemistry CY - Cambridge ER - TY - JOUR A1 - Mazumder, Mostafizur A1 - Brechun, Katherine E. A1 - Kim, Yongjoo B. A1 - Hoffmann, Stefan A. A1 - Chen, Yih Yang A1 - Keiski, Carrie-Lynn A1 - Arndt, Katja Maren A1 - McMillen, David R. A1 - Woolley, G. Andrew T1 - An Escherichia coli system for evolving improved light-controlled DNA-binding proteins JF - Protein engineering design & selection N2 - Light-switchable proteins offer numerous opportunities as tools for manipulating biological systems with exceptional degrees of spatiotemporal control. Most designed light-switchable proteins currently in use have not been optimised using the randomisation and selection/screening approaches that are widely used in other areas of protein engineering. Here we report an approach for screening light-switchable DNA-binding proteins that relies on light-dependent repression of the transcription of a fluorescent reporter. We demonstrate that the method can be used to recover a known light-switchable DNA-binding protein from a random library. KW - directed evolution KW - fluorescent reporter KW - optogenetics Y1 - 2015 U6 - https://doi.org/10.1093/protein/gzv033 SN - 1741-0126 SN - 1741-0134 VL - 28 IS - 9 SP - 293 EP - 302 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Massie, Thomas Michael A1 - Weithoff, Guntram A1 - Kucklaender, Nina A1 - Gaedke, Ursula A1 - Blasius, Bernd T1 - Enhanced Moran effect by spatial variation in environmental autocorrelation JF - Nature Communications N2 - Spatial correlations in environmental stochasticity can synchronize populations over wide areas, a phenomenon known as the Moran effect. The Moran effect has been confirmed in field, laboratory and theoretical investigations. Little is known, however, about the Moran effect in a common ecological case, when environmental variation is temporally autocorrelated and this autocorrelation varies spatially. Here we perform chemostat experiments to investigate the temporal response of independent phytoplankton populations to autocorrelated stochastic forcing. In contrast to naive expectation, two populations without direct coupling can be more strongly correlated than their environmental forcing (enhanced Moran effect), if the stochastic variations differ in their autocorrelation. Our experimental findings are in agreement with numerical simulations and analytical calculations. The enhanced Moran effect is robust to changes in population dynamics, noise spectra and different measures of correlation-suggesting that noise-induced synchrony may play a larger role for population dynamics than previously thought. Y1 - 2015 U6 - https://doi.org/10.1038/ncomms6993 SN - 2041-1723 VL - 6 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Marcus, Tamar A1 - Boch, Steffen A1 - Durka, Walter A1 - Fischer, Markus A1 - Gossner, Martin M. A1 - Müller, Jörg A1 - Schöning, Ingo A1 - Weisser, Wolfgang W. A1 - Drees, Claudia A1 - Assmann, Thorsten T1 - Living in Heterogeneous Woodlands - Are Habitat Continuity or Quality Drivers of Genetic Variability in a Flightless Ground Beetle? JF - PLoS one N2 - Although genetic diversity is one of the key components of biodiversity, its drivers are still not fully understood. While it is known that genetic diversity is affected both by environmental parameters as well as habitat history, these factors are not often tested together. Therefore, we analyzed 14 microsatellite loci in Abax parallelepipedus, a flightless, forest dwelling ground beetle, from 88 plots in two study regions in Germany. We modeled the effects of historical and environmental variables on allelic richness, and found for one of the regions, the Schorfheide-Chorin, a significant effect of the depth of the litter layer, which is a main component of habitat quality, and of the sampling effort, which serves as an inverse proxy for local population size. For the other region, the Schwabische Alb, none of the potential drivers showed a significant effect on allelic richness. We conclude that the genetic diversity in our study species is being driven by current local population sizes via environmental variables and not by historical processes in the studied regions. This is also supported by lack of genetic differentiation between local populations sampled from ancient and from recent woodlands. We suggest that the potential effects of former fragmentation and recolonization processes have been mitigated by the large and stable local populations of Abax parallelepipedus in combination with the proximity of the ancient and recent woodlands in the studied landscapes. Y1 - 2015 U6 - https://doi.org/10.1371/journal.pone.0144217 SN - 1932-6203 VL - 10 IS - 12 PB - PLoS CY - San Fransisco ER - TY - JOUR A1 - Manning, Pete A1 - Gossner, Martin M. A1 - Bossdorf, Oliver A1 - Allan, Eric A1 - Zhang, Yuan-Ye A1 - Prati, Daniel A1 - Blüthgen, Nico A1 - Boch, Steffen A1 - Böhm, Stefan A1 - Börschig, Carmen A1 - Hölzel, Norbert A1 - Jung, Kirsten A1 - Klaus, Valentin H. A1 - Klein, Alexandra-Maria A1 - Kleinebecker, Till A1 - Krauss, Jochen A1 - Lange, Markus A1 - Müller, Jörg A1 - Pasalic, Esther A1 - Socher, Stephanie A. A1 - Tschapka, Marco A1 - Türke, Manfred A1 - Weiner, Christiane A1 - Werner, Michael A1 - Gockel, Sonja A1 - Hemp, Andreas A1 - Renner, Swen C. A1 - Wells, Konstans A1 - Buscot, Francois A1 - Kalko, Elisabeth K. V. A1 - Linsenmair, Karl Eduard A1 - Weisser, Wolfgang W. A1 - Fischer, Markus T1 - Grassland management intensification weakens the associations among the diversities of multiple plant and animal taxa JF - Ecology : a publication of the Ecological Society of America N2 - Land-use intensification is a key driver of biodiversity change. However, little is known about how it alters relationships between the diversities of different taxonomic groups, which are often correlated due to shared environmental drivers and trophic interactions. Using data from 150 grassland sites, we examined how land-use intensification (increased fertilization, higher livestock densities, and increased mowing frequency) altered correlations between the species richness of 15 plant, invertebrate, and vertebrate taxa. We found that 54% of pairwise correlations between taxonomic groups were significant and positive among all grasslands, while only one was negative. Higher land-use intensity substantially weakened these correlations(35% decrease in rand 43% fewer significant pairwise correlations at high intensity), a pattern which may emerge as a result of biodiversity declines and the breakdown of specialized relationships in these conditions. Nevertheless, some groups (Coleoptera, Heteroptera, Hymenoptera and Orthoptera) were consistently correlated with multidiversity, an aggregate measure of total biodiversity comprised of the standardized diversities of multiple taxa, at both high and lowland-use intensity. The form of intensification was also important; increased fertilization and mowing frequency typically weakened plant-plant and plant-primary consumer correlations, whereas grazing intensification did not. This may reflect decreased habitat heterogeneity under mowing and fertilization and increased habitat heterogeneity under grazing. While these results urge caution in using certain taxonomic groups to monitor impacts of agricultural management on biodiversity, they also suggest that the diversities of some groups are reasonably robust indicators of total biodiversity across a range of conditions. KW - Biodiversity indicators KW - correlation KW - fertilization KW - grassland management KW - grazing KW - land-use change KW - land-use intensity KW - mowing KW - multidiversity KW - multitrophic interactions Y1 - 2015 U6 - https://doi.org/10.1890/14-1307.1 SN - 0012-9658 SN - 1939-9170 VL - 96 IS - 6 SP - 1492 EP - 1501 PB - Wiley CY - Washington ER - TY - JOUR A1 - Makower, A. Katharina A1 - Schuurmans, J. Merijn A1 - Groth, Detlef A1 - Zilliges, Yvonne A1 - Matthijs, Hans C. P. A1 - Dittmann-Thünemann, Elke T1 - Transcriptomics-Aided dissection of the intracellular and extracellular roles of microcystin in microcystis aeruginosa PCC 7806 JF - Applied and environmental microbiology N2 - Recent studies have provided evidence for both intracellular and extracellular roles of the potent hepatotoxin microcystin (MC) in the bloom-forming cyanobacterium Microcystis. Here, we surveyed transcriptomes of the wild-type strain M. aeruginosa PCC 7806 and the microcystin-deficient Delta mcyB mutant under low light conditions with and without the addition of external MC of the LR variant (MC-LR). Transcriptomic data acquired by microarray and quantitative PCR revealed substantial differences in the relative expression of genes of the central intermediary metabolism, photosynthesis, and energy metabolism. In particular, the data provide evidence for a lower photosystem I (PSI)-to-photosystem II (PSII) ratio and a more pronounced carbon limitation in the microcystin-deficient mutant. Interestingly, only 6% of the transcriptional differences could be complemented by external microcystin-LR addition. This MC signaling effect was seen exclusively for genes of the secondary metabolism category. The orphan polyketide synthase gene cluster IPF38-51 was specifically downregulated in response to external MC-LR under low light. Our data suggest a hierarchical and light-dependent cross talk of secondary metabolites and support both an intracellular and an extracellular role of MC in Microcystis. Y1 - 2015 U6 - https://doi.org/10.1128/AEM.02601-14 SN - 0099-2240 SN - 1098-5336 VL - 81 IS - 2 SP - 544 EP - 554 PB - American Society for Microbiology CY - Washington ER - TY - JOUR A1 - Ludwig, Arne A1 - Reissmann, Monika A1 - Benecke, Norbert A1 - Bellone, Rebecca A1 - Sandoval-Castellanos, Edson A1 - Cieslak, Michael A1 - González-Fortes, Gloria M. A1 - Morales-Muniz, Arturo A1 - Hofreiter, Michael A1 - Pruvost, Melanie T1 - Twenty-five thousand years of fluctuating selection on leopard complex spotting and congenital night blindness in horses JF - Philosophical transactions of the Royal Society of London : B, Biological sciences N2 - Leopard complex spotting is inherited by the incompletely dominant locus, LP, which also causes congenital stationary night blindness in homozygous horses. We investigated an associated single nucleotide polymorphism in the TRPM1 gene in 96 archaeological bones from 31 localities from Late Pleistocene (approx. 17 000 YBP) to medieval times. The first genetic evidence of LP spotting in Europe dates back to the Pleistocene. We tested for temporal changes in the LP associated allele frequency and estimated coefficients of selection by means of approximate Bayesian computation analyses. Our results show that at least some of the observed frequency changes are congruent with shifts in artificial selection pressure for the leopard complex spotting phenotype. In early domestic horses from Kirklareli-Kanligecit (Turkey) dating to 2700-2200 BC, a remarkably high number of leopard spotted horses (six of 10 individuals) was detected including one adult homozygote. However, LP seems to have largely disappeared during the late Bronze Age, suggesting selection against this phenotype in early domestic horses. During the Iron Age, LP reappeared, probably by reintroduction into the domestic gene pool from wild animals. This picture of alternating selective regimes might explain how genetic diversity was maintained in domestic animals despite selection for specific traits at different times. KW - ancient DNA KW - coat colour KW - domestication KW - Equus KW - palaeogenetics KW - population Y1 - 2015 U6 - https://doi.org/10.1098/rstb.2013.0386 SN - 0962-8436 SN - 1471-2970 VL - 370 IS - 1660 PB - Royal Society CY - London ER - TY - JOUR A1 - Lotkowska, Magda E. A1 - Tohge, Takayuki A1 - Fernie, Alisdair A1 - Xue, Gang-Ping A1 - Balazadeh, Salma A1 - Müller-Röber, Bernd T1 - The Arabidopsis Transcription Factor MYB112 Promotes Anthocyanin Formation during Salinity and under High Light Stress JF - Plant physiology : an international journal devoted to physiology, biochemistry, cellular and molecular biology, biophysics and environmental biology of plants N2 - MYB transcription factors (TFs) are important regulators of flavonoid biosynthesis in plants. Here, we report MYB112 as a formerly unknown regulator of anthocyanin accumulation in Arabidopsis (Arabidopsis thaliana). Expression profiling after chemically induced overexpression of MYB112 identified 28 up-and 28 down-regulated genes 5 h after inducer treatment, including MYB7 and MYB32, which are both induced. In addition, upon extended induction, MYB112 also positively affects the expression of PRODUCTION OF ANTHOCYANIN PIGMENT1, a key TF of anthocyanin biosynthesis, but acts negatively toward MYB12 and MYB111, which both control flavonol biosynthesis. MYB112 binds to an 8-bp DNA fragment containing the core sequence (A/T/G)(A/C) CC(A/T)(A/G/T)(A/C)(T/C). By electrophoretic mobility shift assay and chromatin immunoprecipitation coupled to quantitative polymerase chain reaction, we show that MYB112 binds in vitro and in vivo to MYB7 and MYB32 promoters, revealing them as direct downstream target genes. We further show that MYB112 expression is up-regulated by salinity and high light stress, environmental parameters that both require the MYB112 TF for anthocyanin accumulation under these stresses. In contrast to several other MYB TFs affecting anthocyanin biosynthesis, MYB112 expression is not controlled by nitrogen limitation or an excess of carbon. Thus, MYB112 constitutes a regulator that promotes anthocyanin accumulation under abiotic stress conditions. Y1 - 2015 U6 - https://doi.org/10.1104/pp.15.00605 SN - 0032-0889 SN - 1532-2548 VL - 169 IS - 3 SP - 1862 EP - 1880 PB - American Society of Plant Physiologists CY - Rockville ER - TY - JOUR A1 - Lombardo, Veronica A. A1 - Otten, Cecile A1 - Abdelilah-Seyfried, Salim T1 - Large-scale Zebrafish Embryonic Heart Dissection for Transcriptional Analysis JF - Journal of visualized experiments N2 - The zebrafish embryonic heart is composed of only a few hundred cells, representing only a small fraction of the entire embryo. Therefore, to prevent the cardiac transcriptome from being masked by the global embryonic transcriptome, it is necessary to collect sufficient numbers of hearts for further analyses. Furthermore, as zebrafish cardiac development proceeds rapidly, heart collection and RNA extraction methods need to be quick in order to ensure homogeneity of the samples. Here, we present a rapid manual dissection protocol for collecting functional/beating hearts from zebrafish embryos. This is an essential prerequisite for subsequent cardiac-specific RNA extraction to determine cardiac-specific gene expression levels by transcriptome analyses, such as quantitative real-time polymerase chain reaction (RT-qPCR). The method is based on differential adhesive properties of the zebrafish embryonic heart compared with other tissues; this allows for the rapid physical separation of cardiac from extracardiac tissue by a combination of fluidic shear force disruption, stepwise filtration and manual collection of transgenic fluorescently labeled hearts. KW - Developmental Biology KW - Issue 95 KW - zebrafish KW - embryo KW - heart KW - dissection KW - RNA KW - RT-qPCR Y1 - 2015 U6 - https://doi.org/10.3791/52087 SN - 1940-087X IS - 95 PB - JoVE CY - Cambridge ER -