TY - JOUR A1 - Köchy, Martin T1 - Effects of simulated daily precipitation patterns on annual plant populations depend on life stage and climatic region N2 - Background To improve the understanding of consequences of climate change for annual plant communities, I used a detailed, grid-based model that simulates the effect of daily rainfall variability on individual plants in five climatic regions on a gradient from 100 to 800 mm mean annual precipitation (MAP). The model explicitly considers moisture storage in the soil. I manipulated daily rainfall variability by changing the daily mean rain (DMR, rain volume on rainy days averaged across years for each day of the year) by ± 20%. At the same time I adjusted intervals appropriately between rainy days for keeping the mean annual volume constant. In factorial combination with changing DMR I also changed MAP by ± 20%. Results Increasing MAP generally increased water availability, establishment, and peak shoot biomass. Increasing DMR increased the time that water was continuously available to plants in the upper 15 to 30 cm of the soil (longest wet period, LWP). The effect of DMR diminished with increasing humidity of the climate. An interaction between water availability and density-dependent germination increased the establishment of seedlings in the arid region, but in the more humid regions the establishment of seedlings decreased with increasing DMR. As plants matured, competition among individuals and their productivity increased, but the size of these effects decreased with the humidity of the regions. Therefore, peak shoot biomass generally increased with increasing DMR but the effect size diminished from the semiarid to the mesic Mediterranean region. Increasing DMR reduced via LWP the annual variability of biomass in the semiarid and dry Mediterranean regions. Conclusion More rainstorms (greater DMR) increased the recharge of soil water reservoirs in more arid sites with consequences for germination, establishment, productivity, and population persistence. The order of magnitudes of DMR and MAP overlapped partially so that their combined effect is important for projections of climate change effects on annual vegetation. Y1 - 2008 UR - http://www.biomedcentral.com/1472-6785/8/4 ER - TY - JOUR A1 - Scheffler, Ingo T1 - Zur Fähigkeit von Ektoparasiten der Fledermäuse ihre Wirte aktiv aufzusuchen N2 - Active host-searching in bat ectoparasites. As a pilot study, this paper discribes the mobility of ectoparasites after removing from their hosts. Spinturnix acuminatus (Koch, 1836)(Acari, Spinturnicidae) a permanent stationary bat mite normally survives the removing only a few hours. This species moves easily on the patagium or on human skin. In contrast, on other surfaces the movements of this species seems to be less orientated and it is unlikely that the mite can reach a host in some distance. Nycteribia kolenatii Theodor & Moscona, 1954 (Diptera: Nycteribiidae) a bat fly, shows excellent movements in the fur of its host. The specimens survive the removing from the host several days. The ability to clamber up a wall was tested with a rough clay brick. The bat fly achieves only 9,6 cm on average. This result does not support good abilities for host searching in this species. Bat fleas (Siphonaptera: Ischnopsyllidae): Ischnopsyllus elongatus (Curtis, 1832), I. hexactenus (Kolenati, 1856), I. simplex (Rothschild, 1906)and other species survive the removing from their hosts several days. In case of a vertical barrier they showed a stereotype upside climbing, followed by a horizontal appetitive behavior. The fleas were climbing a distance in the upside of 6,45 m on average(1,2-21,68 m). As excellent climbers bat fleas are able to overcome edges and slopes and to crawl on the ceiling. Therefore, it seems to be no problem for a flea to parasite any bat in a resting room. Additionally, some bugs (Cimex lectularius Linnaeus, 1758) were examinated. They run with a speed of 63 cm per minute and were able to climb easily on the brick. On average their stretch of way achieved 2,85 m in ten minutes. Y1 - 2008 ER - TY - JOUR A1 - Behrsing, Olaf A1 - Micheel, Burkhard T1 - Monoklonale Antikörper : Grundlagen und ihre Bedeutung in Diagnostik und Therapie Y1 - 2008 SN - 978-3-540-69412-0 ER - TY - JOUR A1 - Köchy, Martin A1 - Mathaj, Martin A1 - Jeltsch, Florian A1 - Malkinson, Dan T1 - Resilience of stocking capacity to changing climate in arid to Mediterranean landscapes N2 - Small livestock is an important resource for rural human populations in dry climates. How strongly will climate change affect the capacity of the rangeland? We used hierarchical modelling to scale quantitatively the growth of shrubs and annual plants, the main food of sheep and goats, to the landscape extent in the eastern Mediterranean region. Without grazing, productivity increased in a sigmoid way with mean annual precipitation. Grazing reduced productivity more strongly the drier the landscape. At a point just under the stocking capacity of the vegetation, productivity declined precipitously with more intense grazing due to a lack of seed production of annuals. We repeated simulations with precipitation patterns projected by two contrasting IPCC scenarios. Compared to results based on historic patterns, productivity and stocking capacity did not differ in most cases. Thus, grazing intensity remains the stronger impact on landscape productivity in this dry region even in the future. Y1 - 2008 UR - http://www.springerlink.com/content/gj0567116q770036/ U6 - https://doi.org/10.1007/s10113-008-0048-6 ER - TY - JOUR A1 - Berg, Christian A1 - Bilz, Melanie A1 - Ristow, Michael A1 - Raab, Bernd T1 - Important Plant Areas (IPA) : ein internationales Konzept zum Schutz der Wildpflanzen der Erde Y1 - 2008 ER - TY - JOUR A1 - Koechy, Martin A1 - Brakenhielm, Sven T1 - Separation of effects of moderate N deposition from natural change in ground vegetation of forests and bogs N2 - The effect of moderate rates of nitrogen deposition on ground floor vegetation is poorly predicted by uncontrolled surveys or fertilization experiments using high rates of nitrogen (N) addition. We compared the temporal trends of ground floor vegetation in permanent plots with moderate (7-13 kg/ha/yr) and lower bulk N deposition (4-6 kg/ha/yr) in southern Sweden during 1982-1998. We examined whether trends differed between growth forms (vascular plants and bryophytes) and vegetation types (three types of coniferous forest, deciduous forest, and bog). Trends of site-standardized cover and richness varied among growth forms, vegetation types, and deposition regions. Cover in spruce forests decreased at the same rate with both moderate and low deposition. In pine forests cover decreased faster with moderate deposition and in bogs cover decreased faster with low deposition. Cover of bryophytes in spruce forests increased at the same rate with both moderate and low deposition. In pine forests cover decreased faster with moderate deposition and in bogs and deciduous forests there was a strong non-linear increase with moderate deposition. The trend of number of vascular plants was constant with moderate and decreased with low deposition. We found no trend in the number of bryophyte species. We propose that the decrease of cover and number with low deposition was related to normal ecosystem development (increased shading), suggesting that N deposition maintained or increased the competitiveness of some species in the moderate-deposition region. Deposition had no consistent negative effect on vegetation suggesting that it is less important than normal successional processes. Y1 - 2008 UR - http://dx.doi.org/10.1016/j.foreco.2007.11.039 U6 - https://doi.org/10.1016/j.foreco.2007.11.039 ER - TY - JOUR A1 - Sellrie, Frank A1 - Warsinke, Axel A1 - Micheel, Burkhard T1 - Homogeneous indirect fluorescence quenching immunoassay for the determination of low molecular weight substances JF - Analytical & bioanalytical chemistry N2 - This paper describes the principle of a homogeneous indirect fluorescence quenching immunoassay that uses monoclonal antibodies. It is a carrier-free assay system that is performed completely in solution. The assay system was established for the determination of a low molecular weight substance (hapten), the herbicide diuron, used as a model analyte. A fluorescein-monuron conjugate together with a fluorescence-quenching monoclonal anti-fluorescein antibody and an anti-analyte antibody (here an anti-diuron/monuron monoclonal antibody) were used as central components of the assay. The fluorescein-monuron conjugate can be bound either by the anti-fluorescein monoclonal antibody or by the anti-diuron/ monuron monoclonal antibody. Due to steric hindrance, binding of both antibodies to the conjugate was not possible at the same time. By selecting the antibody concentrations appropriately, a dynamic equilibrium can be established that permits the preferential binding of the anti-diuron/monuron antibody to the conjugate, which allows the fluorescein in the conjugate to fluoresce. This equilibrium can be easily altered by adding free analyte (diuron), which competes with the conjugate to bind to the anti-diuron/monuron antibody. A reduction of anti-diuron/monuron antibody binding to the conjugate results in an increase in the binding of the anti-fluorescein antibody, which leads to a decrease in the fluorescence of the conjugate. The fluorescence is therefore a direct indicator of the state of equilibrium of the system and thus also the presence of free unconjugated analyte. The determination of an analyte based on this test principle does not require any washing steps. After the test components are mixed, the dynamic equilibrium is rapidly reached and the results can be obtained in less than 5 min by measuring the fluorescence of the fluorescein. We used this test principle for the determination of diuron, which was demonstrated for concentrations of approximately 5 nM. Y1 - 2008 UR - http://www.springerlink.com/content/n7227875454216v7/ VL - 386 IS - 2 SP - 206 EP - 210 ER - TY - JOUR A1 - Schlag, Peter M. A1 - Osterziel, Karl Joseph A1 - Özcelik, Cemil A1 - Scherneck, Siegfried A1 - Wenzel, Katrin A1 - Daskalow, Katjana A1 - Herse, Florian A1 - Seitz, Susanne A1 - Zacharias, Ute A1 - Schenk, Jörg A. A1 - Schulz, Herbert A1 - Hübner, Norbert A1 - Micheel, Burkhard T1 - The protein phosphatase 1 inhibitor KEPI is down regulated in breast cancer cell lines and tissues and involved in the regulation of the tumour suppressor EGR1 via the MEK-ERK pathway N2 - KEPI is a protein kinase C-potentiated inhibitory protein for type 1 Ser/Thr protein phosphatases. We found no or reduced expression of KEPI in breast cancer cell lines, breast tumors and metastases in comparison to normal breast cell lines and tissues, respectively. KEPI protein expression and ubiquitous localization was detected with a newly generated antibody. Ectopic KEPI expression in MCF7 breast cancer cells induced differential expression of 95 genes, including the up-regulation of the tumor suppressors EGR1 (early growth response 1) and PTEN (phosphatase and tensin homolog), which is regulated by EGR1. We further show that the up-regulation of EGR1 in MCF7/KEPI cells is mediated by MEK-ERK signaling. The inhibition of this pathway by the MEK inhibitor UO126 led to a strong decrease in EGR1 expression in MCF7/KEPI cells. These results reveal a novel role for KEPI in the regulation of the tumor suppressor gene EGR1 via activation of the MEK-ERK MAPK pathway. Y1 - 2008 UR - http://www.atypon-link.com/doi/abs/10.1515/BC.2007.062 ER - TY - JOUR A1 - Scheffler, Christiane A1 - Voigt, Andrea T1 - Vergleich statischer und dynamischer Körpermaße von Jüngeren (20 - 29 Jahre) und Älteren (50 - 85 Jahre) Y1 - 2008 SN - 978-3-88383-734-2 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 - Kappel, Christian A1 - Trost, Gerda A1 - Czesnick, Hjördis A1 - Ramming, Anna A1 - Kolbe, Benjamin A1 - Vi, Son Lang A1 - Bispo, Cláudia A1 - Becker, Jörg D. A1 - de Moor, Cornelia A1 - Lenhard, Michael T1 - Genome-Wide Analysis of PAPS1-Dependent Polyadenylation Identifies Novel Roles for Functionally Specialized Poly(A) Polymerases in Arabidopsis thaliana JF - PLoS Genetics : a peer-reviewed, open-access journal N2 - The poly(A) tail at 3’ ends of eukaryotic mRNAs promotes their nuclear export, stability and translational efficiency, and changes in its length can strongly impact gene expression. The Arabidopsis thaliana genome encodes three canonical nuclear poly(A) polymerases, PAPS1, PAPS2 and PAPS4. As shown by their different mutant phenotypes, these three isoforms are functionally specialized, with PAPS1 modifying organ growth and suppressing a constitutive immune response. However, the molecular basis of this specialization is largely unknown. Here, we have estimated poly(A)-tail lengths on a transcriptome-wide scale in wild-type and paps1 mutants. This identified categories of genes as particularly strongly affected in paps1 mutants, including genes encoding ribosomal proteins, cell-division factors and major carbohydrate-metabolic proteins. We experimentally verified two novel functions of PAPS1 in ribosome biogenesis and redox homoeostasis that were predicted based on the analysis of poly(A)-tail length changes in paps1 mutants. When overlaying the PAPS1-dependent effects observed here with coexpression analysis based on independent microarray data, the two clusters of transcripts that are most closely coexpressed with PAPS1 show the strongest change in poly(A)-tail length and transcript abundance in paps1 mutants in our analysis. This suggests that their coexpression reflects at least partly the preferential polyadenylation of these transcripts by PAPS1 versus the other two poly(A)-polymerase isoforms. Thus, transcriptome-wide analysis of poly(A)-tail lengths identifies novel biological functions and likely target transcripts for polyadenylation by PAPS1. Data integration with large-scale co-expression data suggests that changes in the relative activities of the isoforms are used as an endogenous mechanism to co-ordinately modulate plant gene expression. KW - messenger-rna polyadenylation KW - differential expression analysis KW - gene-expression KW - tail-length KW - cytoplasmic polyadenylation KW - poly(a)-binding protein KW - translational control KW - comprehensive analysis KW - specificity factor KW - mammalian-cells Y1 - 2015 U6 - https://doi.org/10.1371/journal.pgen.1005474 SN - 1553-7390 SN - 1553-7404 VL - 11 IS - 8 PB - Public Library of Science CY - San Francisco ER - TY - JOUR A1 - Muiño, Jose M. A1 - de Bruijn, Suzanne A1 - Pajoro, Alice A1 - Geuten, Koen A1 - Vingron, Martin A1 - Angenent, Gerco C. A1 - Kaufmann, Kerstin T1 - Evolution of DNA-Binding Sites of a Floral Master Regulatory Transcription Factor JF - Molecular biology and evolution : MBE N2 - lower development is controlled by the action of key regulatory transcription factors of the MADS-domain family. The function of these factors appears to be highly conserved among species based on mutant phenotypes. However, the conservation of their downstream processes is much less well understood, mostly because the evolutionary turnover and variation of their DNA-binding sites (BSs) among plant species have not yet been experimentally determined. Here, we performed comparative ChIP (chromatin immunoprecipitation)-seq experiments of the MADS-domain transcription factor SEPALLATA3 (SEP3) in two closely related Arabidopsis species: Arabidopsis thaliana and A. lyrata which have very similar floral organ morphology. We found that BS conservation is associated with DNA sequence conservation, the presence of the CArG-box BS motif and on the relative position of the BS to its potential target gene. Differences in genome size and structure can explain that SEP3 BSs in A. lyrata can be located more distantly to their potential target genes than their counterparts in A. thaliana. In A. lyrata, we identified transposition as a mechanism to generate novel SEP3 binding locations in the genome. Comparative gene expression analysis shows that the loss/gain of BSs is associated with a change in gene expression. In summary, this study investigates the evolutionary dynamics of DNA BSs of a floral key-regulatory transcription factor and explores factors affecting this phenomenon. KW - MADS-domain transcription factor KW - plant development KW - cis-regulatory evolution Y1 - 2015 U6 - https://doi.org/10.1093/molbev/msv210 SN - 1537-1719 SN - 0737-4038 VL - 33 IS - 1 PB - Oxford University Press CY - Oxford ER - TY - JOUR A1 - Sicard, Adrien A1 - Kappel, Christian A1 - Josephs, Emily B. A1 - Wha Lee, Young A1 - Marona, Cindy A1 - Stinchcombe, John R. A1 - Wright, Stephen I. A1 - Lenhard, Michael T1 - Divergent sorting of a balanced ancestral polymorphism underlies the establishment of gene-flow barriers in Capsella JF - Nature Communications N2 - In the Bateson–Dobzhansky–Muller model of genetic incompatibilities post-zygotic gene-flow barriers arise by fixation of novel alleles at interacting loci in separated populations. Many such incompatibilities are polymorphic in plants, implying an important role for genetic drift or balancing selection in their origin and evolution. Here we show that NPR1 and RPP5 loci cause a genetic incompatibility between the incipient species Capsella grandiflora and C. rubella, and the more distantly related C. rubella and C. orientalis. The incompatible RPP5 allele results from a mutation in C. rubella, while the incompatible NPR1 allele is frequent in the ancestral C. grandiflora. Compatible and incompatible NPR1 haplotypes are maintained by balancing selection in C. grandiflora, and were divergently sorted into the derived C. rubella and C. orientalis. Thus, by maintaining differentiated alleles at high frequencies, balancing selection on ancestral polymorphisms can facilitate establishing gene-flow barriers between derived populations through lineage sorting of the alternative alleles. Y1 - 2015 U6 - https://doi.org/10.1038/ncomms8960 SN - 2041-1723 VL - 6 PB - Nature Publishing Group CY - London ER - TY - JOUR A1 - Valente, Luis M. A1 - Phillimore, Albert B. A1 - Etienne, Rampal S. T1 - Equilibrium and non-equilibrium dynamics simultaneously operate in the Galápagos islands JF - Ecology letters N2 - Island biotas emerge from the interplay between colonisation, speciation and extinction and are often the scene of spectacular adaptive radiations. A common assumption is that insular diversity is at a dynamic equilibrium, but for remote islands, such as Hawaii or Galápagos, this idea remains untested. Here, we reconstruct the temporal accumulation of terrestrial bird species of the Galápagos using a novel phylogenetic method that estimates rates of biota assembly for an entire community. We show that species richness on the archipelago is in an ascending phase and does not tend towards equilibrium. The majority of the avifauna diversifies at a slow rate, without detectable ecological limits. However, Darwin's finches form an exception: they rapidly reach a carrying capacity and subsequently follow a coalescent-like diversification process. Together, these results suggest that avian diversity of remote islands is rising, and challenge the mutual exclusivity of the non-equilibrium and equilibrium ecological paradigms. KW - Community assembly KW - diversification KW - dynamic equilibrium KW - island biogeography KW - phylogeny Y1 - 2015 U6 - https://doi.org/10.1111/ele.12461 SN - 1461-0248 SN - 1461-023X VL - 18 SP - 844 EP - 852 PB - Wiley-Blackwell CY - Oxford ER - TY - JOUR A1 - Steup, Martin T1 - Raum und Zahl in der Pflanzenphysiologie JF - Raum und Zahl Y1 - 2015 SN - 978-3-86464-082-7 SP - 77 EP - 109 PB - Trafo CY - Berlin 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 -