On the origin of the widespread self-compatible allotetraploid Capsella bursa-pastoris (Brassicaceae)

Polyploidy, or whole-genome duplication, is a common speciation mechanism in plants. An important barrier to polyploid establishment is a lack of compatible mates. Because self-compatibility alleviates this problem, it has long been hypothesized that there should be an association between polyploidy and self-compatibility (SC), but empirical support for this prediction is mixed. Here, we investigate whether the molecular makeup of the Brassicaceae self-incompatibility (SI) system, and specifically dominance relationships among S-haplotypes mediated by small RNAs, could facilitate loss of SI in allopolyploid crucifers. We focus on the allotetraploid species Capsella bursa-pastoris, which formed similar to 300 kya by hybridization and whole-genome duplication involving progenitors from the lineages of Capsella orientalis and Capsella grandiflora. We conduct targeted long-read sequencing to assemble and analyze eight full-length S-locus haplotypes, representing both homeologous subgenomes of C. bursa-pastoris. We further analyze small RNA (sRNA) sequencing data from flower buds to identify candidate dominance modifiers. We find that C. orientalis-derived S-haplotypes of C. bursa-pastoris harbor truncated versions of the male SI specificity gene SCR and express a conserved sRNA-based candidate dominance modifier with a target in the C. grandiflora-derived S-haplotype. These results suggest that pollen-level dominance may have facilitated loss of SI in C. bursa-pastoris. Finally, we demonstrate that spontaneous somatic tetraploidization after a wide cross between C. orientalis and C. grandiflora can result in production of self-compatible tetraploid offspring. We discuss the implications of this finding on the mode of formation of this widespread weed

Hybrid seed incompatibility in Capsella is connected to chromatin condensation defects in the endosperm

Hybridization of closely related plant species is frequently connected to endosperm arrest and seed failure, for reasons that remain to be identified. In this study, we investigated the molecular events accompanying seed failure in hybrids of the closely related species pair Capsella rubella and C. grandiflora. Mapping of QTL for the underlying cause of hybrid incompatibility in Capsella identified three QTL that were close to pericentromeric regions. We investigated whether there are specific changes in heterochromatin associated with interspecific hybridizations and found a strong reduction of chromatin condensation in the endosperm, connected with a strong loss of CHG and CHH methylation and random loss of a single chromosome. Consistent with reduced DNA methylation in the hybrid endosperm, we found a disproportionate deregulation of genes located close to pericentromeric regions, suggesting that reduced DNA methylation allows access of transcription factors to targets located in heterochromatic regions. Since the identified QTL were also associated with pericentromeric regions, we propose that relaxation of heterochromatin in response to interspecies hybridization exposes and activates loci leading to hybrid seed failure.Author summarySeed failure in response to interspecific hybridizations is a well-known reproductive barrier preventing interbreeding of closely related species and thus maintaining species boundaries. This reproductive barrier is established in the endosperm, a nourishing tissue supporting embryo growth. In this study, we discovered that the endosperm of interspecific hybrids between the recently diverged species Capsella rubella and C. grandiflora suffers from mitotic abnormalities and random chromosome loss. We found that the endosperm has reduced levels of DNA methylation and chromatin condensation, likely accounting for the chromosome loss. Importantly, we found that genes located in pericentromeric regions were preferentially deregulated, suggesting that reduced DNA methylation exposes transcription factor binding sites in pericentromeric regions, leading to hyperactivation of genes and seed arrest. In support of the relevance of pericentromeric regions for hybrid seed arrest, we identified three QTL connected with the phenotype that were all located in pericentromeric regions. These results link epigenetic changes in hybrid endosperm with distinct genetic loci underpinning hybrid seed failure

Reflexion, Begleitung, Austausch – Die Online-Plattform StudentBodies-AN1 zur Prävention von Magersucht

Internetbasierte Gesundheitsinterventionen (IGI) finden aufgrund ihrer Vorteile und Möglichkeiten eine zunehmende Verbreitung und sind zugleich ein innovatives Forschungsfeld. Sie ermöglichen eine schnelle und weite Verbreitung bei relativ geringen Kosten pro Teilnehmer/in. Die ortsunabhängige Zugänglichkeit der Gesundheitsangebote erleichtert die Versorgung auch im ländlichen Raum. Weitere Vorteile bestehen in der zeitlich unabhängigen Nutzung, die sich leicht in den individuellen Tagesablauf integrieren lässt, ebenso wie in der Wahrung der Anonymität der Nutzer/innen, die eine offene und ehrliche Auseinandersetzung mit potentiell schwierigen Themen in einer Gruppe erleichtern kann. Diese Erwartungen sind die logische Konsequenz von Befunden aus der Grundlagenforschung zu computervermittelter Kommunikation

Kleinkredit und Marktteilhabe in der Vormoderne: Projektdesign

Our project explores the significance of small-scale and even micro-credit for the social and economic life of medieval societies. For the early modern period, scholars such as Laurence Fontaine, Jürgen Schlumbohm or Gabriele Clemens have proposed that social coherence is particularly generated by the individual possibilities of market participation. In three case studies from different European regions we put this assumption to a test in view of late medieval societies. Previous research in medieval studies has rightly pointed to a significant lack of sources for small-scale and micro credits. Therefore, all three case studies aim to identify new types of sources which have previoulsy not or only marginally been used to explore medieval credit activities

An evaluation of the evidence brief for policy development process in WHO EVIPNet Europe countries.

BACKGROUND: Evidence briefs for policy (EBPs) represent a potentially powerful tool for supporting evidence-informed policy-making. Since 2012, WHO Evidence-Informed Policy Network (EVIPNet) Europe has been supporting Member States in developing EBPs. The aim of this study was to evaluate the process of developing EBPs in Estonia, Hungary and Slovenia. METHODS: We used a rapid appraisal approach, combining semi-structured interviews and document review, guided by the Medical Research Council (MRC) process evaluation framework. Interviews were conducted with a total of 20 individuals familiar with the EBP process in the three study countries. Data were analysed thematically, and emerging themes were related back to the MRC framework components (implementation, mechanisms of impact, and context). We also reflected on the appropriateness of this evaluation approach for EVIPNet teams without evaluation research expertise to conduct themselves. RESULTS: The following themes emerged as important to the EBP development process: how the focus problem is prioritized, who initiates this process, EBP team composition, EBP team leadership, availability of external support in the process, and the culture of policy-making in a country. In particular, the EBP process seemed to be supported by early engagement of the Ministry of Health and other stakeholders as initiators, clear EBP team roles and expectations, including a strong leader, external support to strengthen EBP team capacity and cultural acceptance of the necessity of evidence-informed policy-making. Overall, the evaluation approach was considered feasible by the EBP teams and captured rich qualitative data, but may be limited by the absence of external reviewers and long lag times between the EBP process and the evaluation. CONCLUSIONS: This process occurs in a complex system and must be conceptualized in each country and each EBP project in a way that fits local policy-making culture, priorities, leadership and team styles, roles and available resources. The use of a rapid appraisal approach, combining qualitative interviews and document review, is a feasible method of process evaluation for EVIPNet member countries

MOVING: A User-Centric Platform for Online Literacy Training and Learning

Part of the Progress in IS book series (PROIS)In this paper, we present an overview of the MOVING platform, a user-driven approach that enables young researchers, decision makers, and public administrators to use machine learning and data mining tools to search, organize, and manage large-scale information sources on the web such as scientific publications, videos of research talks, and social media. In order to provide a concise overview of the platform, we focus on its front end, which is the MOVING web application. By presenting the main components of the web application, we illustrate what functionalities and capabilities the platform offer its end-users, rather than delving into the data analysis and machine learning technologies that make these functionalities possible

The genomes of two key bumblebee species with primitive eusocial organization

Background: The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some species. High-quality genomic data will inform key aspects of bumblebee biology, including susceptibility to implicated population viability threats. Results: We report the high quality draft genome sequences of Bombus terrestris and Bombus impatiens, two ecologically dominant bumblebees and widely utilized study species. Comparing these new genomes to those of the highly eusocial honeybee Apis mellifera and other Hymenoptera, we identify deeply conserved similarities, as well as novelties key to the biology of these organisms. Some honeybee genome features thought to underpin advanced eusociality are also present in bumblebees, indicating an earlier evolution in the bee lineage. Xenobiotic detoxification and immune genes are similarly depauperate in bumblebees and honeybees, and multiple categories of genes linked to social organization, including development and behavior, show high conservation. Key differences identified include a bias in bumblebee chemoreception towards gustation from olfaction, and striking differences in microRNAs, potentially responsible for gene regulation underlying social and other traits. Conclusions: These two bumblebee genomes provide a foundation for post-genomic research on these key pollinators and insect societies. Overall, gene repertoires suggest that the route to advanced eusociality in bees was mediated by many small changes in many genes and processes, and not by notable expansion or depauperation

Politik mit dem Einkaufswagen : Unternehmen und Konsumenten als Bürger in der globalen Mediengesellschaft

Forschungsprojekt gefördert durch die DFGEine gegenseitige Durchdringung von Zivilgesellschaft und Markt manifestiert sich in der Politisierung des Konsums und der Selbstinszenierung von Unternehmen als sozial verantwortliche Bürger. Dies wirft grundlegende Fragen zur Neubestimmung von Bürgerschaftskonzepten und zur Erweiterung des Handlungsrepertoires von Protestakteuren in spätmodernen Konsumgesellschaften auf. Dabei fungieren (neue) Medien sowohl als Vermittler unternehmerischen Engagements als auch als Plattform für die Ausbildung neuer Protestformen. Der Band liefert einen Beitrag zur aktuellen Diskussion und versammelt Perspektiven von Wissenschaftlern und Praktikern