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Natural variation of flowering time due to cis-regulatory evolution of FLOWERING LOCUS T and its orthologs and paralogs in Brassica napus

Das Projekt "Natural variation of flowering time due to cis-regulatory evolution of FLOWERING LOCUS T and its orthologs and paralogs in Brassica napus" wird vom Umweltbundesamt gefördert und von Max-Planck-Institut für Pflanzenzüchtungsforschung, Abteilung Entwicklungsbiologie der Pflanzen durchgeführt. In many plant species, FLOWERING LOCUS T and related proteins are the mobile signal that communicates information on photoperiod from the leaves to the shoots, where the transition to flowering is realized. FT expression is tightly controlled at the transcriptional level so that it is restricted to leaves, occurs only in appropriate photoperiods, and integrates ambient temperature and developmental cues, as well as information on biotic and abiotic stress. We previously established that FT transcription in the model plant Arabidopsis thaliana requires proximal promoter cis-elements and a distal enhancer, both evolutionary conserved among Brassicacea species. In addition, FT transcription is blocked prior vernalization in biannual accessions and vernalization-dependency of FT is controlled through a CArG-box located in the first intron that binds the transcriptional repressor FLOWERING LOCUS C (FLC). Chromatin-mediated repression by the Polycomb Group (PcG) pathway is required for photoperiod-dependent FT regulation and participates in FT expression level modulation in response to other cues.In this project, I propose to explore the available sequence data from the 1001 genome project in Arabidopsis to evaluate how often changes in regulatory cis-elements at FT have occurred and how these translate into an adaptive value. Allele-specific FT expression pattern will be measured in F1 hybrids of different accessions in response to varying environmental conditions. FT alleles that show cis-regulatory variation will be further analyzed to pinpoint the causal regulatory changes and study their effect in more detail. The allotetrapolyploid species Brassica napus is a hybrid of two Brassiceae species belonging to the A- and C-type genome, which are in turn mesopolyploid due to a genome triplication that occurred ca. 10x106 years ago. We will determine allele-specific expression of FT paralogs from both genomes of a collection of B. napus accessions. The plants will be grown in the field in changing environmental conditions to maximize the chance to detect expression variation of the paralogs. We will compare the contribution of the founder genomes to the regulation of flowering time and asses variation in this contribution. A particular focus will be to study the impact of chromatin-mediated repression on allele selection in B. napus.

Palaeo-Evo-Devo of Malacostraca - a key to the evolutionary history of 'higher' crustaceans

Das Projekt "Palaeo-Evo-Devo of Malacostraca - a key to the evolutionary history of 'higher' crustaceans" wird vom Umweltbundesamt gefördert und von Universität Greifswald, Zoologisches Institut und Museum, Abteilung Cytologie und Evolutionsbiologie durchgeführt. In my project I aim at a better understanding of the evolution of malacostracan crustaceans, which includes very different groups such as mantis shrimps, krill and lobsters. Previous studies on Malacostraca, on extant as well as on fossil representatives, focussed on adult morphology.In contrast to such approaches, I will apply a Palaeo-Evo-Devo approach to shed new light on the evolution of Malacostraca. Palaeo-Evo-Devo uses data of different developmental stages of fossil malacostracan crustaceans, such as larval and juvenile stages. With this approach I aim at bridging morphological gaps between the different diverse lineages of modern malacostracans by providing new insights into the character evolution in these lineages.An extensive number of larval and juvenile malacostracans is present in the fossil record, but which have only scarcely been studied. The backbone of this project will be on malacostracans from the Solnhofen Lithographic Limestones (ca. 150 million years old), which are especially well preserved and exhibit minute details. During previous studies, I developed new documentation methods for tiny fossils from these deposits, e.g., fluorescence composite microscopy, and also discovered the first fossil mantis shrimp larvae. For malcostracan groups that do not occur in Solnhofen, I will investigate fossils from other lagerstätten, e.g., Mazon Creek and Bear Gulch (USA), or Montceaules- Mines and La-Voulte-sur-Rhône (France). The main groups in focus are mantis shrimps and certain other shrimps (e.g., mysids, caridoids), as well as the bottom-living ten-footed crustaceans (reptantians). Examples for studied structures are leg details, including the feeding apparatus, but also eyes. The results will contribute to the reconstruction of 3D computer models.The data collected in this project will be used for evaluating the relationships within Malacostraca, but mainly for providing plausible evolutionary scenarios, how the modern malacostracan diversity evolved. With the Palaeo-Evo-Devo approach, I am also able to detect shifts in developmental timing, called heterochrony, which is interpreted as one of the major driving forces of evolution. Finally, the reconstructed evolutionary patterns can be compared between the different lineages for convergencies. These comparisons might help to explain the convergent adaptation to similar ecological niches in different malacostracan groups, e.g., life in the deep sea, life on the sea bottom, evolution of metamorphosis or of predatory larvae.As the project requires the investigation of a large number of specimens in different groups, I will assign distinct sub-projects to three doctoral researchers. The results of this project will not only be published in peer-reviewed journals, but will also be presented to the non-scientific public, e.g., during fossil fairs or museum exhibitions with 3D models engraved in glass blocks.

Is the immune system required to adapt to flowering time change?

Das Projekt "Is the immune system required to adapt to flowering time change?" wird vom Umweltbundesamt gefördert und von Universität Köln, Biozentrum, Botanisches Institut durchgeführt. For effective crop improvement, breeders must be able to select on relevant phenotypic traits without compromising yield. This project proposes to investigate the evolutionary consequences of flowering time modifications on a second trait of major importance for plant breeding: immunity. This will have implications both for understanding cross-talks between flowering time and defense network and for developing efficient breeding strategies. There is clear evidence that plant maturity influences levels and effectiveness of defense. Theoretical models actually predict that changes in life-history can modulate the balance between costs and benefits of immunity. Simultaneously, actors of the immune system have often been observed to alter flowering time. Two alternative and possibly complementary hypotheses can explain this link: genetic constraints due to the pleiotropic action of players in either systems, or co-evolution, if flowering-time changes modulate the cost-benefit balance of immunity. We will conduct field assays in Arabidopsis thaliana, using constructed lines as well as recombinant inbred lines and natural accessions, to differentiate the action of the two explanatory hypotheses. Using transcriptome analyses, we will identify defense genes associating with flowering time modification (f-t-a defense genes). We will quantify their expression along the assay and test whether it varies with both flowering time and fitness. We will further test whether flowering time and immunity interact to determine yield in tomato and potato.

Eco-evolutionary responses and feedbacks of a key herbivore to lake oligotrophication

Das Projekt "Eco-evolutionary responses and feedbacks of a key herbivore to lake oligotrophication" wird vom Umweltbundesamt gefördert und von Universität Konstanz, Limnologisches Institut durchgeführt. The project will use analysis of long-term data, resurrection ecology and modeling to investigate the ecological and evolutionary response of an aquatic key herbivore, Daphnia, to environmental change. In addition, the results obtained will enable to estimate the consequences of the evolutionary response of Daphnia for its population dynamics, persistence and consequently, overall ecosystem dynamics. The project will analyze in detail the response of Daphnia, its food, competitors and predators to oligo-trophication in a model ecosystem, i.e., Lake Constance and additionally variability in Daphnia population dynamics in several of the best studied lakes of the world. Historical field samples from Lake Constance will be re-analyzed to study the phenotypic life history and morphological responses of Daphnia to oligo-trophication. Using resurrection ecology we will analyze the evolutionary response of Daphnia galeata life history parameters to oligo-trophication - with special emphasis on its investment into sexual reproduction/production of resting eggs as well as life history plasticity in response to invertebrate predators and declining food levels. These analyses (in combination with model simulations) will provide key data for understanding the role of Daphnia life cycle strategy (overwintering in the plankton or in resting eggs) for Daphnia persistence in permanent lakes, for the interpretation of Daphnia resting egg banks, and the evolution of the genetic variances and co-variances of life history parameters.

Biochemie der Peroxidasine

Das Projekt "Biochemie der Peroxidasine" wird vom Umweltbundesamt gefördert und von Universität für Bodenkultur Wien, Institut für Chemie durchgeführt. Enzyme der Peroxidase-Cyclooxygenase Superfamilie katalysieren biochemische Reaktionen, die in unzähligen biologischen Prozessen eine wichtige Rolle spielen, z.B. bei der unspezifischen Immunabwehr, der Synthese der Schilddrüsenhormone oder der Bildung und Modifizierung der extrazellulären Matrix. Sie sind zudem auch bei der Pathogenese von chronischen entzündlichen Erkrankungen beteiligt. In der Subfamilie 2 dieser Superfamilie findet man Multidomänen-Oxidoreduktasen, sog. Peroxidasine (Pxds). Hierbei handelt es sich um glykosylierte und sekretierte Häm-Peroxidasen, die zusätzlich zur katalytischen Domäne sog. Leucin-reiche Wiederholungssequenzen, Immunoglobulin C-ähnliche Domänen sowie von Willebrandfaktor C enthalten. Diese Strukturmotive finden sich in vielen extrazellulären Molekülen, die mit anderen Proteinen in Wechselwirkung treten. Ursprünglich wurde Peroxidasin in Basalmembranen von Drosophila entdeckt. Spätere Arbeiten zeigten, dass diese Enzyme auch in Wirbeltieren vorkommen und eine Rolle bei der unspezifischen Immunabwehr, der Gewebsbildung, Ausbreitung von Tumoren und oxidativen Prozessen eine Rolle spielen. Kürzlich wurde gezeigt, dass dieses Metallprotein mit Hilfe von Hypohalogeniten im Kollegen IV für die Bildung von kovalenten Kohlenstoff-Stickstoffbindungen verantwortlich ist, ein Prozess, der sowohl bei der Gewebsbildung als auch bei zahlreichen Kranksheitsbildern eine wichtige Rolle spielt. Trotz der physiologischen Bedeutung dieser neuen Proteinfamilie ist das biochemische Wissen sehr bescheiden. In diesem Projekt sollen daher, basierend auf umfangreichen phylogenetischen Voranalysen und der bereits erfolgreich durchgeführten rekombinanten Produktion von humanem Peroxidasin 1 in tierischen Zellkulturen, die Struktur-Funktionsbeziehungen von vier Peroxidasinen unterschiedlicher Entwicklungsstufe und Sequenz analysiert werden: Peroxidasin 1 von Caenorhabditis elegans, Pxd von Drosophila melanogaster als auch die beiden humanen Peroxidasine 1 & 2. Basierend auf der rekombinanten Produktion der vier Modell-Proteine in voller Kettenlänge bzw. von verkürzten Varianten unterschiedlicher Domänenzusammensetzung werden umfangreiche bio-chemische/biophysikalische Analysen durchgeführt: (i) UV-vis-, Fluoreszenz- CD-, Lichtstreuung-, RR- und ESR-Spektroskopie, (ii) Stopped-flow-Spektroskopie und Polarographie, (iii) MS und Röntgenkristallographie, (v) Spektroelektrochemie und (vi) Kalorimetrie. Mit Hilfe dieser Methoden sollen Struktur und Aktivität der Peroxidasine aufgeklärt werden wie z.B. (i) oligomere Struktur und Architektur des aktiven Zentrums, (ii) Interaktion der Domänen und Mechanismen der Proteinentfaltung, (iii) Chemie der prosthetischen Gruppe inklusive Oxidations- und Spinzustände, Häm-Liganden und posttranslationale Modifizierungen, (iv) Spezifität, Zugänglichkeit, und Bindungorte von Substraten als auch chemische Natur der Reaktionsprodukte (v) Chemie, Reaktivität und Relevanz von Redox-Intermediaten und (vi) die Ro

Towards understanding the determinants of stream macroinvertebrate responses to environmental change mediated by glacial recession

Das Projekt "Towards understanding the determinants of stream macroinvertebrate responses to environmental change mediated by glacial recession" wird vom Umweltbundesamt gefördert und von Eawag - Das Wasserforschungsinstitut des ETH-Bereichs durchgeführt. The world is currently experiencing a major biodiversity crisis due to human activities. A primary concern is the on-going and rapid biological consequences of global climate change. Climate change is impacting alpine landscapes at unprecedented rates, with severe impacts on landscape structure and catchment hydrodynamics, as well as temperature regimes of glacial-fed rivers. Most glaciers are expected to be dramatically reduced and many even gone by the year 2100, concomitantly with changes (timing and magnitude) in temperature and precipitation. These environmental changes are predicted to have strong impacts on the persistence and distribution of alpine organisms, their population structure and community assembly, and, ultimately, ecosystem functioning. However, how alpine biodiversity (aquatic macroinvertebrates in our case) will respond to these changes is poorly understood. Most previous studies predict the presence of species based on the distribution of putatively suitable habitats but ignore biotic traits, such as dispersal, and potential eco-evolutionary responses to such changes. Clearly, accurate predictions on species responses require integrative studies incorporating landscape dynamics with eco-evolutionary processes. The primary goal of the proposed research is to empirically test determinants of alpine macroinvertebrate responses to rapid environmental change mediated by glacial recession. Climate-induced glacial retreat is occurring rapidly and in a replicated fashion (i.e. over multiple catchments and continents), which provides a natural experiment for testing determinants of organismal and species diversity responses to climate change in alpine waters. The responses of alpine aquatic macroinvertebrates are highly important because of their known sensitivity (i.e. response rates) to environmental change and their fundamental role in ecosystem functioning. Using an integrative comparative and experimental approach, we will target the following main question: What are the roles of ecological and evolutionary processes in population level responses of macroinvertebrates to environmental change? The study will take advantage of rapid glacial recession (environmental change) to empirically examine spatio-temporal patterns in species distribution in nature, combined with experimental and population genetics approaches. The data generated will be used to explicitly address the role of eco-evolutionary processes (determinants) on population level responses for selected key species. Spatial and temporal variation in species distribution, phenotypic and genetic variation will be quantified for two stream macroinvertebrates (hemimetabolous mayfly Baetis alpinus, holometabolous caddisfly Allogamus uncatus), and measuring landscape features and physico-chemical parameters along longitudinal transects downstream of glaciers and selected side-slope tributaries (as potential stepping stones for dispersal and colonization).

Shifts in the climate niche of mammals: evolutionary constraints or adaptation potential?

Das Projekt "Shifts in the climate niche of mammals: evolutionary constraints or adaptation potential?" wird vom Umweltbundesamt gefördert und von Universität Freiburg, Institut für Geo- und Umweltnaturwissenschaften, Abteilung für Biometrie und Umweltsystemanalyse durchgeführt. Predictions of effects of climate change on species distributions assume constant climatic niches. Our current understanding of how climate niches developed through evolution is very limited. This project shall analyse how climate niche of the 5488 mammal species worldwide is related to their phylogenetic position. The hypothesis is that closely related species will also have similar climate niches, indicating climate niche conservation. Based on current distributions and environmental data, we shall quantify the climate niche of each species and compare it to that of its closest relative (sister species). We shall investigate whether climate niche position is similarly phylogenetically constrained as other species traits such as body weight, gestation length or litter size. The huge breadth of mammal ecologies, their highly resolved phylogenetic tree, their high conservation relevance and their relatively well-known geographical distribution make them an ideal study system. In the process of this study, new methodological standards for the analysis of niche evolution will be developed, including randomisation tests, virtual species analysis and character tracing of climate niche position. In the end, we shall be able to specify the adaptation potential to climate change for a large number of species studied.

Evolutionary Conflicts and their Impact on Speciation (follow-up)

Das Projekt "Evolutionary Conflicts and their Impact on Speciation (follow-up)" wird vom Umweltbundesamt gefördert und von Eidgenössische Technische Hochschule Zürich, Institut für Integrative Biologie durchgeführt. In addition to recognizing natural selection as a universal mechanism in evolution, Darwin also saw the importance of sexual selection, yet the two have been traditionally treated largely in isolation. Here I propose to apply experimental evolution (exposing experimental populations to controlled specific selective pressures over many generations in the laboratory) to the ideally suited model system Tribolium castaneum to explore how these evolutionary forces interact and impact on the key processes underlying biodiversity. Understanding how these fundamental forces, singly and in conjunction, influence species divergence remains a major challenge in evolutionary biology. Participation of sexual selection in driving speciation is supported by substantial theoretical evidence. Theory further suggests that evolutionary conflicts (such as between the sexes or between host and parasite) might also accelerate extinction. Additional complexity is introduced by including the environmental context, linking back to natural selection. Direct experimental tests of the above concepts are essentially lacking. I will explicitly target this gap by exploiting powerful experimental evolution, incorporating the interplay between sexual selection intensity, host-parasite conflict, and adaptation to increasing temperature. Projects will assess how selection under evolutionary conflict and environmental change affects both adaptation and extinction rates, aiming to elucidate underlying mechanisms. Additionally, building on clear phenotypic divergence in key traits across experimental evolution lines, I will significantly expand on previous work by assessing patterns of divergence in gene expression, concentrating on target genes associated with reproduction, immunity and heat shock. This research will be of particular interest to scientists working in the fields of evolutionary biology and behavioural ecology, but also to ecologists, reproductive biologists, and conservation biologists. As Tribolium beetles are widespread agricultural pests, results will also be relevant to more applied researchers.

Teilprojekt A: Functional genomics of floral transition in sugar beet

Das Projekt "Teilprojekt A: Functional genomics of floral transition in sugar beet" wird vom Umweltbundesamt gefördert und von Christian-Albrechts-Universität Kiel, Institut für Pflanzenbau und Pflanzenzüchtung durchgeführt. Background: The transition from vegetative to generative growth in the lifetime of a flowering plant is triggered by a number of genes together with endogenous stimuli as well as environmental cues, such as temperature or day length changes. To ensure optimal reproductive success, flowering plants have developed different life cycles. While annual species complete their life cycle in one year, biennial species need to overwinter and thus finish their life cycle in the second year. The genetic control of photoperiodic flowering has been elucidated in the model plant Arabidopsis thaliana, while many of the identified genes are structurally conserved in all known plants. Recently, the bolting locus BOLTING TIME CONTROL 1 (BTC1) was discovered to control annuality through regulation of the two beet FT homologs BvFT1 and BvFT2. BTC1 shares sequence homology with the PSEUDO RESPONSE REGULATOR 7 (PRR7) gene from A. thaliana which is part of the circadian clock system. A homolog of Arabidopsis PRR7 in beet, BvPRR7, was also identified, and work is in progress to determine the function of this gene which belongs to the same gene family like BTC1. Besides BTC1, several promising bolting time loci (B2, B3, B4) have been identified after an EMS mutagenesis of an annual beet accession. Dominant alleles at these loci promote annual bolting. Objectives: We aim to understand the genetic network that regulates floral transition in sugar beet, with the long-term objective of providing a tool kit for targeted modification of bolting and flowering time. Applications in plant breeding include suppression of vernalization-responsiveness to enable winter cultivation and marker-assisted selection for synchronization of flowering time for hybrid seed production, as well as understanding and expanding the evolutionary relationship of flowering time pathways between Beta and other species. Results: Putative orthologs of flowering time genes in model species were identified by homology-based methods, and 20 genes were mapped on a genetic map of sugar beet. Genome-wide transcript analyses have revealed new insights into the genetic and environmental regulation of floral transition in sugar beet. Recently, results from a functional characterization revealed that the FLC-like gene BvFL1 does not function as a major regulator of vernalization response in biennial beet, but overexpression results in a moderate late-bolting phenotype. By contrast, RNAi-induced down-regulation of the BvFT1-BvFT2 module led to a strong delay in bolting after vernalization by several weeks. The data demonstrate for the first time that an FLC homolog does not play a major role in the control of vernalization response in a dicot species outside the Brassicaceae.

EpiCOL: Ecological and Evolutionary plant epigenetics (09-EuroEEFG-FP-048)

Das Projekt "EpiCOL: Ecological and Evolutionary plant epigenetics (09-EuroEEFG-FP-048)" wird vom Umweltbundesamt gefördert und von Universität Bern, Departement Biologie, Institut für Pflanzenwissenschaften durchgeführt. One of the fundamental principles in biology is that evolution by natural selection, and therefore the ability of populations to adapt to changing environments, requires heritable variation, i.e. genetically-based variation in phenotypic traits that are under selection. Until recently, such heritable variation was generally thought to require underlying DNA sequence variation. Thus, populations that lack DNA sequence variation were assumed be unable to evolve. However, there is now increasing evidence that epigenetic modifications of the genome, such as DNA methylation or histone modifications - which regulate gene activity and therefore ultimately the phenotype - can be heritable, too, and that there can be epigenetic variation within and among natural populations which is independent of DNA sequence variation. Moreover, epigenetic variation can sometimes be altered direct by the environment, which suggests that such heritable epigenetic variation might be an important and hitherto overlooked component of biodiversity and an additional mechanism for organisms to respond to environmental change. Our project is part of a larger pan-European project (involving partners from the Netherlands, Germany, Austria and France) that attempts to address these exciting questions about the ecological and evolutionary relevance of epigenetic variation and epigenetic inheritance in several connected sub-projects. In our project, we will test the hypothesis that evolution by natural selection can occur even in the absence of DNA sequence variation, based on heritable epigenetic variation only. We will use selection experiments, and a recently developed, unique set of genotypically near-identical but epigenetically distinct recombinant inbred lines (epiRILs) of Arabidopsis thaliana to study epigenetic evolution 'in action'. The specific objectives of our project are (i) to characterise 100+ epiRILs with regard to their drought and pathogen resistance, (ii) to subject replicated experimental populations of these epiRILs to at least 3-4 generations of natural or artificial selection imposed by experimental drought and/or pathogens, and (iii) to quantify the response to this selection both in terms of phenotypic shifts as well as shifts in epigenotype frequencies.

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