TY - JOUR A1 - Schlägel, Ulrike E. A1 - Lewis, Mark A. T1 - Robustness of movement models: can models bridge the gap between temporal scales of data sets and behavioural processes? JF - Journal of mathematical biology KW - Animal movement KW - Sampling rate KW - Resource selection KW - GPS data KW - Parameter estimation KW - Markov model Y1 - 2016 U6 - https://doi.org/10.1007/s00285-016-1005-5 SN - 0303-6812 SN - 1432-1416 VL - 73 SP - 1691 EP - 1726 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Coutinho, Renato Mendes A1 - Klauschies, Toni A1 - Gaedke, Ursula T1 - Bimodal trait distributions with large variances question the reliability of trait-based aggregate models JF - Theoretical ecology N2 - Functionally diverse communities can adjust their species composition to altered environmental conditions, which may influence food web dynamics. Trait-based aggregate models cope with this complexity by ignoring details about species identities and focusing on their functional characteristics (traits). They describe the temporal changes of the aggregate properties of entire communities, including their total biomasses, mean trait values, and trait variances. The applicability of aggregate models depends on the validity of their underlying assumptions that trait distributions are normal and exhibit small variances. We investigated to what extent this can be expected to work by comparing an innovative model that accounts for the full trait distributions of predator and prey communities to a corresponding aggregate model. We used a food web structure with well-established trade-offs among traits promoting mutual adjustments between prey edibility and predator selectivity in response to selection. We altered the shape of the trade-offs to compare the outcome of the two models under different selection regimes, leading to trait distributions increasingly deviating from normality. Their biomass and trait dynamics agreed very well for stabilizing selection and reasonably well for directional selection, under which different trait values are favored at different times. However, for disruptive selection, the results of the aggregate model strongly deviated from the full trait distribution model that showed bimodal trait distributions with large variances. Hence, the outcome of aggregate models is reliable under ideal conditions but has to be questioned when confronted with more complex selection regimes and trait distributions, which are commonly observed in nature. KW - Fitness gradient KW - Communities as complex adaptive systems KW - Moment closure for trait-based aggregate model approaches KW - Multimodal trait distributions KW - Lumpiness in pattern formation and self-organization KW - Shape of trade-offs and stabilizing and disruptive selection Y1 - 2016 U6 - https://doi.org/10.1007/s12080-016-0297-9 SN - 1874-1738 SN - 1874-1746 VL - 9 SP - 389 EP - 408 PB - Springer CY - Heidelberg ER - TY - JOUR A1 - Reinecke, J. A1 - Wulf, M. A1 - Baeten, Lander A1 - Brunet, J. A1 - Decocq, G. A1 - De Frenne, G. A1 - Diekmann, M. A1 - Graae, B. J. A1 - Heinken, Thilo A1 - Hermy, M. A1 - Jamoneau, A. A1 - Lenoir, J. A1 - Plue, J. A1 - Orczewska, A. A1 - Van Calster, H. A1 - Verheyen, Kris A1 - Naaf, T. T1 - Acido- and neutrophilic temperate forest plants display distinct shifts in ecological pH niche across north-western Europe JF - Ecography : pattern and diversity in ecology ; research papers forum N2 - Ecological niches of organisms vary across geographical space, but niche shift patterns between regions and the underlying mechanisms remain largely unexplored. We studied shifts in the pH niche of 42 temperate forest plant species across a latitudinal gradient from northern France to boreo-nemoral Sweden. We asked 1) whether species restrict their niches with increasing latitude as they reach their northern range margin (environmental constraints); 2) whether species expand their niches with increasing latitude as regional plant species richness decreases (competitive release); and 3) whether species shift their niche position toward more acidic sites with increasing latitude as the relative proportion of acidic soils increases (local adaptation). Based on 1458 vegetation plots and corresponding soil pH values, we modelled species response curves using Huisman-Olff-Fresco models. Four niche measures (width, position, left and right border) were compared among regions by randomization tests. We found that with increasing latitude, neutrophilic species tended to retreat from acidic sites, indicating that these species retreat to more favorable sites when approaching their range margin. Alternatively, these species might benefit from enhanced nitrogen deposition on formerly nutrient-poor, acidic sites in southern regions or lag behind in post-glacial recolonization of potential habitats in northern regions. Most acidophilic species extended their niche toward more base-rich sites with increasing latitude, indicating competitive release from neutrophilic species. Alternatively, acidophilic species might benefit from optimal climatic conditions in the north where some have their core distribution area. Shifts in the niche position suggested that local adaptation is of minor importance. We conclude that shifts in the pH niche of temperate forest plants are the rule, but the directions of the niche shifts and possible explanations vary. Our study demonstrates that differentiating between acidophilic and neutrophilic species is crucial to identify general patterns and underlying mechanisms. Y1 - 2016 U6 - https://doi.org/10.1111/ecog.02051 SN - 0906-7590 SN - 1600-0587 VL - 39 SP - 1164 EP - 1175 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Lachmann, Sabrina C. A1 - Maberly, Stephen C. A1 - Spijkerman, Elly T1 - ECOPHYSIOLOGY MATTERS: LINKING INORGANIC CARBON ACQUISITION TO ECOLOGICAL PREFERENCE IN FOUR SPECIES OF MICROALGAE (CHLOROPHYCEAE) JF - Journal of phycology N2 - The effect of CO2 supply is likely to play an important role in algal ecology. Since inorganic carbon (C-i) acquisition strategies are very diverse among microalgae and C-i availability varies greatly within and among habitats, we hypothesized that C-i acquisition depends on the pH of their preferred natural environment (adaptation) and that the efficiency of C-i uptake is affected by CO2 availability (acclimation). To test this, four species of green algae originating from different habitats were studied. The pH-drift and C-i uptake kinetic experiments were used to characterize C-i acquisition strategies and their ability to acclimate to high and low CO2 conditions and high and low pH was evaluated. Results from pH drift experiments revealed that the acidophile and acidotolerant Chlamydomonas species were mainly restricted to CO2, whereas the two neutrophiles were efficient bicarbonate users. CO2 compensation points in low CO2-acclimated cultures ranged between 0.6 and 1.4 mu M CO2 and acclimation to different culture pH and CO2 conditions suggested that CO2 concentrating mechanisms were present in most species. High CO2 acclimated cultures adapted rapidly to low CO2 condition during pH-drifts. C-i uptake kinetics at different pH values showed that the affinity for C-i was largely influenced by external pH, being highest under conditions where CO2 dominated the C-i pool. In conclusion, C-i acquisition was highly variable among four species of green algae and linked to growth pH preference, suggesting that there is a connection between C-i acquisition and ecological distribution. KW - acidophile KW - carbon acquisition KW - CCM KW - Chlamydomonas KW - Chlorella KW - CO2 supply KW - extremophile KW - inorganic carbon uptake kinetics KW - pH-drift KW - Scenedesmus Y1 - 2016 U6 - https://doi.org/10.1111/jpy.12462 SN - 0022-3646 SN - 1529-8817 VL - 52 SP - 1051 EP - 1063 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Meyer, Sebastian T. A1 - Ebeling, Anne A1 - Eisenhauer, Nico A1 - Hertzog, Lionel A1 - Hillebrand, Helmut A1 - Milcu, Alexandru A1 - Pompe, Sven A1 - Abbas, Maike A1 - Bessler, Holger A1 - Buchmann, Nina A1 - De Luca, Enrica A1 - Engels, Christof A1 - Fischer, Markus A1 - Gleixner, Gerd A1 - Hudewenz, Anika A1 - Klein, Alexandra-Maria A1 - de Kroon, Hans A1 - Leimer, Sophia A1 - Loranger, Hannah A1 - Mommer, Liesje A1 - Oelmann, Yvonne A1 - Ravenek, Janneke M. A1 - Roscher, Christiane A1 - Rottstock, Tanja A1 - Scherber, Christoph A1 - Scherer-Lorenzen, Michael A1 - Scheu, Stefan A1 - Schmid, Bernhard A1 - Schulze, Ernst-Detlef A1 - Staudler, Andrea A1 - Strecker, Tanja A1 - Temperton, Vicky A1 - Tscharntke, Teja A1 - Vogel, Anja A1 - Voigt, Winfried A1 - Weigelt, Alexandra A1 - Wilcke, Wolfgang A1 - Weisser, Wolfgang W. T1 - Effects of biodiversity strengthen over time as ecosystem functioning declines at low and increases at high biodiversity JF - Ecosphere : the magazine of the International Ecology University KW - biodiversity ecosystem functioning (BEF) KW - ecosystem processes KW - grassland KW - mechanism KW - plant productivity KW - plant species richness KW - temporal effects KW - trophic interactions Y1 - 2016 U6 - https://doi.org/10.1002/ecs2.1619 SN - 2150-8925 VL - 7 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Mao, Hailiang A1 - Nakamura, Moritaka A1 - Viotti, Corrado A1 - Grebe, Markus T1 - A Framework for Lateral Membrane Trafficking and Polar Tethering of the PEN3 ATP-Binding Cassette Transporter JF - Plant physiology : an international journal devoted to physiology, biochemistry, cellular and molecular biology, biophysics and environmental biology of plants N2 - The outermost cell layer of plants, the epidermis, and its outer (lateral) membrane domain facing the environment are continuously challenged by biotic and abiotic stresses. Therefore, the epidermis and the outer membrane domain provide important selective and protective barriers. However, only a small number of specifically outer membrane-localized proteins are known. Similarly, molecular mechanisms underlying the trafficking and the polar placement of outer membrane domain proteins require further exploration. Here, we demonstrate that ACTIN7 (ACT7) mediates trafficking of the PENETRATION3 (PEN3) outer membrane protein from the trans-Golgi network (TGN) to the plasma membrane in the root epidermis of Arabidopsis (Arabidopsis thaliana) and that actin function contributes to PEN3 endocytic recycling. In contrast to such generic ACT7-dependent trafficking from the TGN, the EXOCYST84b (EXO84b) tethering factor mediates PEN3 outer-membrane polarity. Moreover, precise EXO84b placement at the outer membrane domain itself requires ACT7 function. Hence, our results uncover spatially and mechanistically distinct requirements for ACT7 function during outer lateral membrane cargo trafficking and polarity establishment. They further identify an exocyst tethering complex mediator of outer lateral membrane cargo polarity. Y1 - 2016 U6 - https://doi.org/10.1104/pp.16.01252 SN - 0032-0889 SN - 1532-2548 VL - 172 SP - 2245 EP - 2260 PB - American Society of Plant Physiologists CY - Rockville ER - TY - JOUR A1 - Procter, Duncan S. A1 - Cottrell, Joan E. A1 - Watts, Kevin A1 - Hofreiter, Michael A1 - Robinson, Elva J. H. T1 - Does cooperation mean kinship between spatially discrete ant nests? JF - Ecology and evolution N2 - Eusociality is one of the most complex forms of social organization, characterized by cooperative and reproductive units termed colonies. Altruistic behavior of workers within colonies is explained by inclusive fitness, with indirect fitness benefits accrued by helping kin. Members of a social insect colony are expected to be more closely related to one another than they are to other conspecifics. In many social insects, the colony can extend to multiple socially connected but spatially separate nests (polydomy). Social connections, such as trails between nests, promote cooperation and resource exchange, and we predict that workers from socially connected nests will have higher internest relatedness than those from socially unconnected, and noncooperating, nests. We measure social connections, resource exchange, and internest genetic relatedness in the polydomous wood ant Formica lugubris to test whether (1) socially connected but spatially separate nests cooperate, and (2) high internest relatedness is the underlying driver of this cooperation. Our results show that socially connected nests exhibit movement of workers and resources, which suggests they do cooperate, whereas unconnected nests do not. However, we find no difference in internest genetic relatedness between socially connected and unconnected nest pairs, both show high kinship. Our results suggest that neighboring pairs of connected nests show a social and cooperative distinction, but no genetic distinction. We hypothesize that the loss of a social connection may initiate ecological divergence within colonies. Genetic divergence between neighboring nests may build up only later, as a consequence rather than a cause of colony separation. KW - colony organization KW - eusociality KW - Formica lugubris KW - kin selection KW - polydomy KW - social organization Y1 - 2016 U6 - https://doi.org/10.1002/ece3.2590 SN - 2045-7758 VL - 6 SP - 8846 EP - 8856 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Cepakova, Zuzana A1 - Hrouzek, Pavel A1 - Ziskova, Eva A1 - Nuyanzina-Boldareva, Ekaterina A1 - Sorf, Michal A1 - Kozlikova-Zapomelova, Eliska A1 - Salka, Ivette A1 - Grossart, Hans-Peter A1 - Koblizek, Michal T1 - High turnover rates of aerobic anoxygenic phototrophs in European freshwater lakes JF - Environmental microbiology N2 - Aerobic Anoxygenic Phototrophic (AAP) bacteria are bacteriochlorophyll (BChl) a -containing organisms which use light energy to supplement their predominantly heterotrophic metabolism. Here, we investigated mortality and growth rates of AAP bacteria in three different freshwater lakes in Central Europe: the mountain lake Plesne, the oligo-mesotrophic Lake Stechlin and the forest pond Huntov. The mortality of AAP bacteria was estimated from diel changes of BChl a fluorescence. Net and gross growth rates were calculated from the increases in AAP cell numbers. The gross growth rates of AAP bacteria ranged from 0.38 to 5.6 d(-1), with the highest values observed during summer months. Simultaneously, the rapidly growing AAP cells have to cope with an intense grazing pressure by both zooplankton and protists. The presented results document that during the day, gross growth usually surpased mortality. Our results indicate that AAP bacteria utilize light energy under natural conditions to maintain rapid growth rates, which are balanced by a generally intense grazing pressure. Y1 - 2016 U6 - https://doi.org/10.1111/1462-2920.13475 SN - 1462-2912 SN - 1462-2920 VL - 18 SP - 5063 EP - 5071 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Wutke, Saskia A1 - Benecke, Norbert A1 - Sandoval-Castellanos, Edson A1 - Döhle, Hans-Jürgen A1 - Friederich, Susanne A1 - Gonzalez Soto, Javier Esteban A1 - Hallsson, Jon Hallsteinn A1 - Hofreiter, Michael A1 - Lougas, Lembi A1 - Magnell, Ola A1 - Morales-Muniz, Arturo A1 - Orlando, Ludovic A1 - Palsdottir, Albina Hulda A1 - Reissmann, Monika A1 - Ruttkay, Matej A1 - Trinks, Alexandra A1 - Ludwig, Arne T1 - Spotted phenotypes in horses lost attractiveness in the Middle Ages JF - Scientific reports N2 - Horses have been valued for their diversity of coat colour since prehistoric times; this is especially the case since their domestication in the Caspian steppe in similar to 3,500 BC. Although we can assume that human preferences were not constant, we have only anecdotal information about how domestic horses were influenced by humans. Our results from genotype analyses show a significant increase in spotted coats in early domestic horses (Copper Age to Iron Age). In contrast, medieval horses carried significantly fewer alleles for these phenotypes, whereas solid phenotypes (i.e., chestnut) became dominant. This shift may have been supported because of (i) pleiotropic disadvantages, (ii) a reduced need to separate domestic horses from their wild counterparts, (iii) a lower religious prestige, or (iv) novel developments in weaponry. These scenarios may have acted alone or in combination. However, the dominance of chestnut is a remarkable feature of the medieval horse population. Y1 - 2016 U6 - https://doi.org/10.1038/srep38548 SN - 2045-2322 VL - 6 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Westbury, Michael V. A1 - Prost, Stefan A1 - Seelenfreund, Andrea A1 - Ramirez, Jose-Miguel A1 - Matisoo-Smith, Elizabeth A. A1 - Knapp, Michael T1 - First complete mitochondrial genome data from ancient South American camelids - The mystery of the chilihueques from Isla Mocha (Chile) JF - Scientific reports Y1 - 2016 U6 - https://doi.org/10.1038/srep38708 SN - 2045-2322 VL - 6 PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Gossner, Martin M. A1 - Lewinsohn, Thomas M. A1 - Kahl, Tiemo A1 - Grassein, Fabrice A1 - Boch, Steffen A1 - Prati, Daniel A1 - Birkhofer, Klaus A1 - Renner, Swen C. A1 - Sikorski, Johannes A1 - Wubet, Tesfaye A1 - Arndt, Hartmut A1 - Baumgartner, Vanessa A1 - Blaser, Stefan A1 - Blüthgen, Nico A1 - Börschig, Carmen A1 - Buscot, Francois A1 - Diekötter, Tim A1 - Jorge, Leonardo Re A1 - Jung, Kirsten A1 - Keyel, Alexander C. A1 - Klein, Alexandra-Maria A1 - Klemmer, Sandra A1 - Krauss, Jochen A1 - Lange, Markus A1 - Müller, Jörg A1 - Overmann, Jörg A1 - Pasalic, Esther A1 - Penone, Caterina A1 - Perovic, David J. A1 - Purschke, Oliver A1 - Schall, Peter A1 - Socher, Stephanie A. A1 - Sonnemann, Ilja A1 - Tschapka, Marco A1 - Tscharntke, Teja A1 - Türke, Manfred A1 - Venter, Paul Christiaan A1 - Weiner, Christiane N. A1 - Werner, Michael A1 - Wolters, Volkmar A1 - Wurst, Susanne A1 - Westphal, Catrin A1 - Fischer, Markus A1 - Weisser, Wolfgang W. A1 - Allan, Eric T1 - Land-use intensification causes multitrophic homogenization of grassland communities JF - Nature : the international weekly journal of science N2 - Land-use intensification is a major driver of biodiversity loss(1,2). Alongside reductions in local species diversity, biotic homogenization at larger spatial scales is of great concern for conservation. Biotic homogenization means a decrease in beta-diversity (the compositional dissimilarity between sites). Most studies have investigated losses in local (alpha)-diversity(1,3) and neglected biodiversity loss at larger spatial scales. Studies addressing beta-diversity have focused on single or a few organism groups (for example, ref. 4), and it is thus unknown whether land-use intensification homogenizes communities at different trophic levels, above-and belowground. Here we show that even moderate increases in local land-use intensity (LUI) cause biotic homogenization across microbial, plant and animal groups, both above- and belowground, and that this is largely independent of changes in alpha-diversity. We analysed a unique grassland biodiversity dataset, with abundances of more than 4,000 species belonging to 12 trophic groups. LUI, and, in particular, high mowing intensity, had consistent effects on beta-diversity across groups, causing a homogenization of soil microbial, fungal pathogen, plant and arthropod communities. These effects were nonlinear and the strongest declines in beta-diversity occurred in the transition from extensively managed to intermediate intensity grassland. LUI tended to reduce local alpha-diversity in aboveground groups, whereas the alpha-diversity increased in belowground groups. Correlations between the alpha-diversity of different groups, particularly between plants and their consumers, became weaker at high LUI. This suggests a loss of specialist species and is further evidence for biotic homogenization. The consistently negative effects of LUI on landscape-scale biodiversity underscore the high value of extensively managed grasslands for conserving multitrophic biodiversity and ecosystem service provision. Indeed, biotic homogenization rather than local diversity loss could prove to be the most substantial consequence of land-use intensification. Y1 - 2016 U6 - https://doi.org/10.1038/nature20575 SN - 0028-0836 SN - 1476-4687 VL - 540 SP - 266 EP - + PB - Nature Publ. Group CY - London ER - TY - JOUR A1 - Sas, Claudia A1 - Mueller, Frank A1 - Kappel, Christian A1 - Kent, Tyler V. A1 - Wright, Stephen I. A1 - Hilker, Monika A1 - Lenhard, Michael T1 - Repeated Inactivation of the First Committed Enzyme Underlies the Loss of Benzaldehyde Emission after the Selfing Transition in Capsella JF - Current biology N2 - The enormous species richness of flowering plants is at least partly due to floral diversification driven by interactions between plants and their animal pollinators [1, 2]. Specific pollinator attraction relies on visual and olfactory floral cues [3-5]; floral scent can not only attract pollinators but also attract or repel herbivorous insects [6-8]. However, despite its central role for plant-animal interactions, the genetic control of floral scent production and its evolutionary modification remain incompletely understood [9-13]. Benzenoids are an important class of floral scent compounds that are generated from phenylalanine via several enzymatic pathways [14-17]. Here we address the genetic basis of the loss of floral scent associated with the transition from outbreeding to selfing in the genus Capsella. While the outbreeding C. grandiflora emits benzaldehyde as a major constituent of its floral scent, this has been lost in the selfing C. rubella. We identify the Capsella CNL1 gene encoding cinnamate: CoA ligase as responsible for this variation. Population genetic analysis indicates that CNL1 has been inactivated twice independently in C. rubella via different novel mutations to its coding sequence. Together with a recent study in Petunia [18], this identifies cinnamate: CoA ligase as an evolutionary hotspot for mutations causing the loss of benzenoid scent compounds in association with a shift in the reproductive strategy of Capsella from pollination by insects to self-fertilization. Y1 - 2016 U6 - https://doi.org/10.1016/j.cub.2016.10.026 SN - 0960-9822 SN - 1879-0445 VL - 26 SP - 3313 EP - 3319 PB - Cell Press CY - Cambridge ER - TY - JOUR A1 - Spijkerman, Elly A1 - Stojkovic, Slobodanka A1 - Holland, Daryl A1 - Lachmann, Sabrina C. A1 - Beardall, John T1 - Nutrient induced fluorescence transients (NIFTs) provide a rapid measure of P and C (co-)limitation in a green alga JF - European journal of phycology N2 - Nutrient Induced Fluorescence Transients (NIFTs) have been shown to be a possible way of testing for the limiting nutrient in algal populations. In this study we tested the hypothesis that NIFTs can be used to detect a (co-)limitation for inorganic phosphorus (Pi) and CO2 in the green alga Chlamydomonas acidophila and that the magnitude of the NIFTs can be related to cellular P:C ratios. We show a co-limitation response for Pi and CO2 via traditional nutrient enrichment experiments in natural phytoplankton populations dominated by C. acidophila. We measured NIFT responses after a Pi- or a CO2-spike in C. acidophila batch cultures at various stages of Pi and inorganic C limitation. Significant NIFTs were observed in response to spikes in both nutrients. The NIFT response to a Pi-spike showed a strong negative correlation with cellular P:C ratio that was pronounced below 3 mmol P: mol C (equivalent to 0.2 pg P cell(-1)). Both cellular P and C content influenced the extent of the Pi-NIFT response. The NIFT response to a CO2-spike correlated to low CO2 culturing conditions and also had a negative correlation with cellular P content. A secondary response within the Pi-NIFT response was related to the CO2 concentration and potentially reflected co-limitation. In conclusion, NIFTs provided a quick and reliable method to detect the growth-limiting nutrient in an extremophile green alga, under Pi-, CO2- and Pi/CO2 (co-)limited growth conditions. KW - acidophile KW - Chlamydomonas KW - CO2 concentrating mechanism KW - CO2 limitation KW - extremophile KW - nutrient limitation KW - photosynthesis response KW - phytoplankton KW - stoichiometry Y1 - 2016 U6 - https://doi.org/10.1080/09670262.2015.1095355 SN - 0967-0262 SN - 1469-4433 VL - 51 SP - 47 EP - 58 PB - Hindawi CY - Abingdon ER - TY - JOUR A1 - Schmidt, Andreas A1 - Rabsch, Wolfgang A1 - Broeker, Nina K. A1 - Barbirz, Stefanie T1 - Bacteriophage tailspike protein based assay to monitor phase variable glucosylations in Salmonella O-antigens JF - BMC microbiology N2 - Background Non-typhoid Salmonella Typhimurium (S. Typhimurium) accounts for a high number of registered salmonellosis cases, and O-serotyping is one important tool for monitoring epidemiology and spread of the disease. Moreover, variations in glucosylated O-antigens are related to immunogenicity and spread in the host. However, classical autoagglutination tests combined with the analysis of specific genetic markers cannot always reliably register phase variable glucose modifications expressed on Salmonella O-antigens and additional tools to monitor O-antigen glucosylation phenotypes of S. Typhimurium would be desirable. Results We developed a test for the phase variable O-antigen glucosylation state of S. Typhimurium using the tailspike proteins (TSP) of Salmonella phages 9NA and P22. We used this ELISA like tailspike adsorption (ELITA) assay to analyze a library of 44 Salmonella strains. ELITA was successful in discriminating strains that carried glucose 1-6 linked to the galactose of O-polysaccharide backbone (serotype O1) from non-glucosylated strains. This was shown by O-antigen compositional analyses of the respective strains with mass spectrometry and capillary electrophoresis. The ELITA test worked rapidly in a microtiter plate format and was highly O-antigen specific. Moreover, TSP as probes could also detect glucosylated strains in flow cytometry and distinguish multiphasic cultures differing in their glucosylation state. Conclusions Tailspike proteins contain large binding sites with precisely defined specificities and are therefore promising tools to be included in serotyping procedures as rapid serotyping agents in addition to antibodies. In this study, 9NA and P22TSP as probes could specifically distinguish glucosylation phenotypes of Salmonella on microtiter plate assays and in flow cytometry. This opens the possibility for flow sorting of cell populations for subsequent genetic analyses or for monitoring phase variations during large scale O-antigen preparations necessary for vaccine production. KW - Salmonella Typhimurium KW - O-antigen KW - Tailspike protein KW - Bacteriophage KW - Phase variation KW - O-serotyping KW - Flow cytometry Y1 - 2016 U6 - https://doi.org/10.1186/s12866-016-0826-0 SN - 1471-2180 VL - 16 PB - BioMed Central CY - London ER - TY - JOUR A1 - Lah, Ljerka A1 - Trense, Daronja A1 - Benke, Harald A1 - Berggren, Per A1 - Gunnlaugsson, Þorvaldur A1 - Lockyer, Christina A1 - Öztürk, Ayaka A1 - Öztürk, Bayram A1 - Pawliczka, Iwona A1 - Roos, Anna A1 - Siebert, Ursula A1 - Skóra, Krzysztof A1 - Víkingsson, Gísli A1 - Tiedemann, Ralph T1 - Spatially Explicit Analysis of Genome-Wide SNPs Detects Subtle Population Structure in a Mobile Marine Mammal, the Harbor Porpoise JF - PLoS one N2 - The population structure of the highly mobile marine mammal, the harbor porpoise (Phocoena phocoena), in the Atlantic shelf waters follows a pattern of significant isolation-by-distance. The population structure of harbor porpoises from the Baltic Sea, which is connected with the North Sea through a series of basins separated by shallow underwater ridges, however, is more complex. Here, we investigated the population differentiation of harbor porpoises in European Seas with a special focus on the Baltic Sea and adjacent waters, using a population genomics approach. We used 2872 single nucleotide polymorphisms (SNPs), derived from double digest restriction-site associated DNA sequencing (ddRAD-seq), as well as 13 microsatellite loci and mitochondrial haplotypes for the same set of individuals. Spatial principal components analysis (sPCA), and Bayesian clustering on a subset of SNPs suggest three main groupings at the level of all studied regions: the Black Sea, the North Atlantic, and the Baltic Sea. Furthermore, we observed a distinct separation of the North Sea harbor porpoises from the Baltic Sea populations, and identified splits between porpoise populations within the Baltic Sea. We observed a notable distinction between the Belt Sea and the Inner Baltic Sea sub-regions. Improved delineation of harbor porpoise population assignments for the Baltic based on genomic evidence is important for conservation management of this endangered cetacean in threatened habitats, particularly in the Baltic Sea proper. In addition, we show that SNPs outperform microsatellite markers and demonstrate the utility of RAD-tags from a relatively small, opportunistically sampled cetacean sample set for population diversity and divergence analysis. Y1 - 2016 U6 - https://doi.org/10.1371/journal.pone.0162792 SN - 1932-6203 VL - 11 IS - 10 PB - PLoS CY - Lawrence, Kan. ER - TY - JOUR A1 - Zhu, Fangjun A1 - Schlupp, Ingo A1 - Tiedemann, Ralph T1 - Sequence Evolution and Expression of the Androgen Receptor and Other Pathway-Related Genes in a Unisexual Fish, the Amazon Molly, Poecilia formosa, and Its Bisexual Ancestors JF - PLoS one N2 - The all-female Amazon molly (Poecilia formosa) originated from a single hybridization of two bisexual ancestors, Atlantic molly (Poecilia mexicana) and sailfin molly (Poecilia latipinna). As a gynogenetic species, the Amazon molly needs to copulate with a heterospecific male, but the genetic information of the sperm-donor does not contribute to the next generation, as the sperm only acts as the trigger for the diploid eggs’ embryogenesis. Here, we study the sequence evolution and gene expression of the duplicated genes coding for androgen receptors (ars) and other pathway-related genes, i.e., the estrogen receptors (ers) and cytochrome P450, family19, subfamily A, aromatase genes (cyp19as), in the Amazon molly, in comparison to its bisexual ancestors. Mollies possess–as most other teleost fish—two copies of the ar, er, and cyp19a genes, i.e., arα/arβ, erα/erβ1, and cyp19a1 (also referred as cyp19a1a)/cyp19a2 (also referred to as cyp19a1b), respectively. Non-synonymous single nucleotide polymorphisms (SNPs) among the ancestral bisexual species were generally predicted not to alter protein function. Some derived substitutions in the P. mexicana and one in P. formosa are predicted to impact protein function. We also describe the gene expression pattern of the ars and pathway-related genes in various tissues (i.e., brain, gill, and ovary) and provide SNP markers for allele specific expression research. As a general tendency, the levels of gene expression were lowest in gill and highest in ovarian tissues, while expression levels in the brain were intermediate in most cases. Expression levels in P. formosa were conserved where expression did not differ between the two bisexual ancestors. In those cases where gene expression levels significantly differed between the bisexual species, P. formosa expression was always comparable to the higher expression level among the two ancestors. Interestingly, erβ1 was expressed neither in brain nor in gill in the analyzed three molly species, which implies a more important role of erα in the estradiol synthesis pathway in these tissues. Furthermore, our data suggest that interactions of steroid-signaling pathway genes differ across tissues, in particular the interactions of ars and cyp19as. Y1 - 2016 U6 - https://doi.org/10.1371/JOURNAL.PONE.0156209 SN - 1932-6203 VL - 11 IS - 6 PB - PLoS CY - Lawrence, Kan. ER - TY - JOUR A1 - Batsios, Petros A1 - Ren, Xiang A1 - Baumann, Otto A1 - Larochelle, Denis A. A1 - Gräf, Ralph T1 - Src1 is a Protein of the Inner Nuclear Membrane Interacting with the Dictyostelium Lamin NE81 JF - Cells N2 - The nuclear envelope (NE) consists of the outer and inner nuclear membrane (INM), whereby the latter is bound to the nuclear lamina. Src1 is a Dictyostelium homologue of the helix-extension-helix family of proteins, which also includes the human lamin-binding protein MAN1. Both endogenous Src1 and GFP-Src1 are localized to the NE during the entire cell cycle. Immuno-electron microscopy and light microscopy after differential detergent treatment indicated that Src1 resides in the INM. FRAP experiments with GFP-Src1 cells suggested that at least a fraction of the protein could be stably engaged in forming the nuclear lamina together with the Dictyostelium lamin NE81. Both a BioID proximity assay and mis-localization of soluble, truncated mRFP-Src1 at cytosolic clusters consisting of an intentionally mis-localized mutant of GFP-NE81 confirmed an interaction of Src1 and NE81. Expression GFP-Src11–646, a fragment C-terminally truncated after the first transmembrane domain, disrupted interaction of nuclear membranes with the nuclear lamina, as cells formed protrusions of the NE that were dependent on cytoskeletal pulling forces. Protrusions were dependent on intact microtubules but not actin filaments. Our results indicate that Src1 is required for integrity of the NE and highlight Dictyostelium as a promising model for the evolution of nuclear architecture. KW - Dictyostelium KW - lamin KW - nuclear lamina KW - nucleus KW - nucleolus KW - HeH-protein KW - LEM-domain protein Y1 - 2016 U6 - https://doi.org/10.3390/cells5010013 SN - 2073-4409 VL - 5 IS - 1 PB - MDPI CY - Basel ER - TY - JOUR A1 - Klauschies, Toni A1 - Vasseur, David A. A1 - Gaedke, Ursula T1 - Trait adaptation promotes species coexistence in diverse predator and prey communities JF - Ecology and evolution N2 - Species can adjust their traits in response to selection which may strongly influence species coexistence. Nevertheless, current theory mainly assumes distinct and time-invariant trait values. We examined the combined effects of the range and the speed of trait adaptation on species coexistence using an innovative multispecies predator–prey model. It allows for temporal trait changes of all predator and prey species and thus simultaneous coadaptation within and among trophic levels. We show that very small or slow trait adaptation did not facilitate coexistence because the stabilizing niche differences were not sufficient to offset the fitness differences. In contrast, sufficiently large and fast trait adaptation jointly promoted stable or neutrally stable species coexistence. Continuous trait adjustments in response to selection enabled a temporally variable convergence and divergence of species traits; that is, species became temporally more similar (neutral theory) or dissimilar (niche theory) depending on the selection pressure, resulting over time in a balance between niche differences stabilizing coexistence and fitness differences promoting competitive exclusion. Furthermore, coadaptation allowed prey and predator species to cluster into different functional groups. This equalized the fitness of similar species while maintaining sufficient niche differences among functionally different species delaying or preventing competitive exclusion. In contrast to pre- vious studies, the emergent feedback between biomass and trait dynamics enabled supersaturated coexistence for a broad range of potential trait adaptation and parameters. We conclude that accounting for trait adaptation may explain stable and supersaturated species coexistence for a broad range of environmental conditions in natural systems when the absence of such adaptive changes would preclude it. Small trait changes, coincident with those that may occur within many natural populations, greatly enlarged the number of coexisting species. KW - Coadaptation KW - equalizing and stabilizing mechanisms KW - maintenance of functional diversity KW - niche and fitness differences KW - supersaturated species coexistence KW - trait convergence and divergence Y1 - 2016 U6 - https://doi.org/10.1002/ece3.2172 SN - 2045-7758 PB - John Wiley & Sons, Inc. ER - TY - JOUR A1 - Yan, Wenhao A1 - Chen, Dijun A1 - Kaufmann, Kerstin T1 - Efficient multiplex mutagenesis by RNA-guided Cas9 and its use in the characterization of regulatory elements in the AGAMOUS gene JF - Plant methods N2 - Background The efficiency of multiplex editing in plants by the RNA-guided Cas9 system is limited by efficient introduction of its components into the genome and by their activity. The possibility of introducing large fragment deletions by RNA-guided Cas9 tool provides the potential to study the function of any DNA region of interest in its ‘endogenous’ environment. Results Here, an RNA-guided Cas9 system was optimized to enable efficient multiplex editing in Arabidopsis thaliana. We demonstrate the flexibility of our system for knockout of multiple genes, and to generate heritable large-fragment deletions in the genome. As a proof of concept, the function of part of the second intron of the flower development gene AGAMOUS in Arabidopsis was studied by generating a Cas9-free mutant plant line in which part of this intron was removed from the genome. Further analysis revealed that deletion of this intron fragment results 40 % decrease of AGAMOUS gene expression without changing the splicing of the gene which indicates that this regulatory region functions as an activator of AGAMOUS gene expression. Conclusions Our modified RNA-guided Cas9 system offers a versatile tool for the functional dissection of coding and non-coding DNA sequences in plants. KW - RNA-guided Cas9 KW - Multiplex mutagenesis KW - Large fragment deletion KW - Germline transmission Y1 - 2016 U6 - https://doi.org/10.1186/s13007-016-0125-7 SN - 1746-4811 VL - 12 SP - 1 EP - 9 PB - BioMed Central CY - London ER - TY - JOUR A1 - Wacker, Alexander A1 - Piepho, Maike A1 - Harwood, John L. A1 - Guschina, Irina A. A1 - Arts, Michael T. T1 - Light-Induced Changes in Fatty Acid Profiles of Specific Lipid Classes in Several Freshwater Phytoplankton Species JF - Frontiers in plant science : FPLS N2 - We tested the influence of two light intensities [40 and 300 μmol PAR / (m2s)] on the fatty acid composition of three distinct lipid classes in four freshwater phytoplankton species. We chose species of different taxonomic classes in order to detect potentially similar reaction characteristics that might also be present in natural phytoplankton communities. From samples of the bacillariophyte Asterionella formosa, the chrysophyte Chromulina sp., the cryptophyte Cryptomonas ovata and the zygnematophyte Cosmarium botrytis we first separated glycolipids (monogalactosyldiacylglycerol, digalactosyldiacylglycerol, and sulfoquinovosyldiacylglycerol), phospholipids (phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, and phosphatidylserine) as well as non-polar lipids (triacylglycerols), before analyzing the fatty acid composition of each lipid class. High variation in the fatty acid composition existed among different species. Individual fatty acid compositions differed in their reaction to changing light intensities in the four species. Although no generalizations could be made for species across taxonomic classes, individual species showed clear but small responses in their ecologically-relevant omega-3 and omega-6 polyunsaturated fatty acids (PUFA) in terms of proportions and of per tissue carbon quotas. Knowledge on how lipids like fatty acids change with environmental or culture conditions is of great interest in ecological food web studies, aquaculture, and biotechnology, since algal lipids are the most important sources of omega-3 long-chain PUFA for aquatic and terrestrial consumers, including humans. KW - freshwater algae KW - light adaptation KW - lipid classes KW - fatty acid changes Y1 - 2016 U6 - https://doi.org/10.3389/fpls.2016.00264 SN - 1664-462X VL - 7 SP - 1 EP - 13 PB - Frontiers Media CY - Lausanne ER -