103 research outputs found

    Chinese species of egg-parasitoids of the genera Oxyscelio Kieffer, Heptascelio Kieffer and Platyscelio Kieffer (Hymenoptera: Platygastridae s.l., Scelioninae)

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    To date, the known Chinese fauna of egg-parasitoids of the genus Oxyscelio Kieffer encompasses two species from the mainland – O. doumao Burks and O. nubbin Burks. Here we record eighteen species of Oxyscelio from collections in mainland China: O. arvi Burks, O. ceylonensis (Dodd), O. convergens Burks, O. cordis Burks, O. crebritas Burks, O. cuculli Burks, O. dermatoglyphes Burks, O. doumao Burks, O. florus Kononova, O. granorum Burks, O. intermedietas Burks, O. jugi Burks, O. kramatos Burks, O. longiventris Burks, O. naraws Kozlov & Lê, O. perpensus Kononova, O. planocarinae Burks, and O. striarum Burks. Oxyscelio is primarily found in the tropics, and most of these species are shared with Taiwan and southeast Asia. Three species previously known only from Japan, O. arvi, O. florus, O. perpensus, are shared. The Chinese species are recorded from Guangdong, Guangxi, Hainan, Hebei, Hunan, Shaanxi, Sichuan, Yunnan and Zhejiang as well as additional material from Taiwan. Heptascelio hamatus Masner & Johnson and Platyscelio pulchricornis Kieffer are both recorded from Hainan and Guangdong, as well as records of P. pulchricornis from Sarawak and Thailand

    Taxonomic description and phylogenetic placement of two new species of Spalangiopelta (Hymenoptera: Pteromalidae: Ceinae) from Eocene Baltic amber

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    Spalangiopelta is a small genus of chalcid wasps that has received little attention despite the widespread distribution of its extant species. The fossil record of the genus is restricted to a single species from Miocene Dominican amber. We describe two new fossil species, Spalangiopelta darlingi sp. n. and Spalangiopelta semialba sp. n. from Baltic amber. The species can be placed within the extant genus Spalangiopelta based on the distinctly raised hind margin of the mesopleuron. 3D models reconstructed from µCT data were utilized to assist in the descriptions. Furthermore, we provide a key for the females of all currently known Spalangiopelta species. The phylogenetic placement of the fossils within the genus is analyzed using parsimony analysis based on morphological characters. Phylogenetic and functional relevance of two wing characters, admarginal setae and the hyaline break, are discussed. The newly described Baltic amber fossils significantly extend the minimum age of Spalangiopelta to the Upper Eocene

    Activin/nodal signaling and NANOG orchestrate human embryonic stem cell fate decisions by controlling the H3K4me3 chromatin mark.

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    Stem cells can self-renew and differentiate into multiple cell types. These characteristics are maintained by the combination of specific signaling pathways and transcription factors that cooperate to establish a unique epigenetic state. Despite the broad interest of these mechanisms, the precise molecular controls by which extracellular signals organize epigenetic marks to confer multipotency remain to be uncovered. Here, we use human embryonic stem cells (hESCs) to show that the Activin-SMAD2/3 signaling pathway cooperates with the core pluripotency factor NANOG to recruit the DPY30-COMPASS histone modifiers onto key developmental genes. Functional studies demonstrate the importance of these interactions for correct histone 3 Lys4 trimethylation and also self-renewal and differentiation. Finally, genetic studies in mice show that Dpy30 is also necessary to maintain pluripotency in the pregastrulation embryo, thereby confirming the existence of similar regulations in vivo during early embryonic development. Our results reveal the mechanisms by which extracellular factors coordinate chromatin status and cell fate decisions in hESCs.We thank Andrew Knights for the technical support and helpful discussion, and the Wellcome-Trust Sanger Institute Microarray and Next-Generation Sequencing facilities for the technical support. We also thank the Sanger Institute Mouse Genetics Projects for mouse production and genotyping. This work was supported by the European Research Council starting grant Relieve-IMDs and the Cambridge Hospitals National Institute for Health Research Biomedical Research Centre (L.V.), a British Heart Foundation Ph.D. Studentship (A.B.), a Federation of European Biochemical Societies (FEBS) long-term fellowship and EU Fp7 grant InnovaLIV (S.P.), EU Fp7 grant TissuGEN (S.M.), and Wellcome Trust grant 098051 (D.G.). A.B. conceived the research, performed and analyzed the experiments, and wrote the manuscript. P.M. computationally analyzed ChIP-seq data sets and performed statistical analyses. N.C.H., S.B., and R.A.P. provided technical support. A.G. performed embryo dissections and dysmorphology assessments. I.M. and D.B. performed teratoma assays. D.G. supervised the bioinformatics data analysis. S.P., S.M., and L.V. conceived the research and wrote the manuscript.This is the final published version. It first appeared at http://genesdev.cshlp.org/content/29/7/702.full

    The Chalcidoidea bush of life: evolutionary history of a massive radiation of minute wasps.

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    Chalcidoidea are mostly parasitoid wasps that include as many as 500 000 estimated species. Capturing phylogenetic signal from such a massive radiation can be daunting. Chalcidoidea is an excellent example of a hyperdiverse group that has remained recalcitrant to phylogenetic resolution. We combined 1007 exons obtained with Anchored Hybrid Enrichment with 1048 ultra-conserved elements (UCEs) for 433 taxa including all extant families, >95% of all subfamilies, and 356 genera chosen to represent the vast diversity of the superfamily. Going back and forth between the molecular results and our collective knowledge of morphology and biology, we detected bias in the analyses that was driven by the saturation of nucleotide data. Our final results are based on a concatenated analysis of the least saturated exons and UCE datasets (2054 loci, 284 106 sites). Our analyses support an expected sister relationship with Mymarommatoidea. Seven previously recognized families were not monophyletic, so support for a new classification is discussed. Natural history in some cases would appear to be more informative than morphology, as illustrated by the elucidation of a clade of plant gall associates and a clade of taxa with planidial first-instar larvae. The phylogeny suggests a transition from smaller soft-bodied wasps to larger and more heavily sclerotized wasps, with egg parasitism as potentially ancestral for the entire superfamily. Deep divergences in Chalcidoidea coincide with an increase in insect families in the fossil record, and an early shift to phytophagy corresponds with the beginning of the "Angiosperm Terrestrial Revolution". Our dating analyses suggest a middle Jurassic origin of 174 Ma (167.3-180.5 Ma) and a crown age of 162.2 Ma (153.9-169.8 Ma) for Chalcidoidea. During the Cretaceous, Chalcidoidea may have undergone a rapid radiation in southern Gondwana with subsequent dispersals to the Northern Hemisphere. This scenario is discussed with regard to knowledge about the host taxa of chalcid wasps, their fossil record and Earth's palaeogeographic history

    A Molecular Phylogeny of the Chalcidoidea (Hymenoptera)

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    Chalcidoidea (Hymenoptera) are extremely diverse with more than 23,000 species described and over 500,000 species estimated to exist. This is the first comprehensive phylogenetic analysis of the superfamily based on a molecular analysis of 18S and 28S ribosomal gene regions for 19 families, 72 subfamilies, 343 genera and 649 species. The 56 outgroups are comprised of Ceraphronoidea and most proctotrupomorph families, including Mymarommatidae. Data alignment and the impact of ambiguous regions are explored using a secondary structure analysis and automated (MAFFT) alignments of the core and pairing regions and regions of ambiguous alignment. Both likelihood and parsimony approaches are used to analyze the data. Overall there is no impact of alignment method, and few but substantial differences between likelihood and parsimony approaches. Monophyly of Chalcidoidea and a sister group relationship between Mymaridae and the remaining Chalcidoidea is strongly supported in all analyses. Either Mymarommatoidea or Diaprioidea are the sister group of Chalcidoidea depending on the analysis. Likelihood analyses place Rotoitidae as the sister group of the remaining Chalcidoidea after Mymaridae, whereas parsimony nests them within Chalcidoidea. Some traditional family groups are supported as monophyletic (Agaonidae, Eucharitidae, Encyrtidae, Eulophidae, Leucospidae, Mymaridae, Ormyridae, Signiphoridae, Tanaostigmatidae and Trichogrammatidae). Several other families are paraphyletic (Perilampidae) or polyphyletic (Aphelinidae, Chalcididae, Eupelmidae, Eurytomidae, Pteromalidae, Tetracampidae and Torymidae). Evolutionary scenarios discussed for Chalcidoidea include the evolution of phytophagy, egg parasitism, sternorrhynchan parasitism, hypermetamorphic development and heteronomy

    Integrated genomic characterization of pancreatic ductal adenocarcinoma

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    We performed integrated genomic, transcriptomic, and proteomic profiling of 150 pancreatic ductal adenocarcinoma (PDAC) specimens, including samples with characteristic low neoplastic cellularity. Deep whole-exome sequencing revealed recurrent somatic mutations in KRAS, TP53, CDKN2A, SMAD4, RNF43, ARID1A, TGFβR2, GNAS, RREB1, and PBRM1. KRAS wild-type tumors harbored alterations in other oncogenic drivers, including GNAS, BRAF, CTNNB1, and additional RAS pathway genes. A subset of tumors harbored multiple KRAS mutations, with some showing evidence of biallelic mutations. Protein profiling identified a favorable prognosis subset with low epithelial-mesenchymal transition and high MTOR pathway scores. Associations of non-coding RNAs with tumor-specific mRNA subtypes were also identified. Our integrated multi-platform analysis reveals a complex molecular landscape of PDAC and provides a roadmap for precision medicine

    A hymenopterists' guide to the hymenoptera anatomy ontology: utility, clarification, and future directions

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    Hymenoptera exhibit an incredible diversity of phenotypes, the result of ~240 million years of evolution and the primary subject of more than 250 years of research. Here we describe the history, development, and utility of the Hymenoptera Anatomy Ontology (HAO) and its associated applications. These resourc¬es are designed to facilitate accessible and extensible research on hymenopteran phenotypes. Outreach with the hymenopterist community is of utmost importance to the HAO project, and this paper is a direct response to questions that arose from project workshops. In a concerted attempt to surmount barriers of understanding, especially regarding the format, utility, and development of the HAO, we discuss the roles of homology, “preferred terms”, and “structural equivalency”. We also outline the use of Universal Resource Identifiers (URIs) and posit that they are a key element necessary for increasing the objectivity and repeatability of science that references hymenopteran anatomy. Pragmatically, we detail a mechanism (the “URI table”) by which authors can use URIs to link their published text to the HAO, and we describe an associated tool (the “Analyzer”) to derive these tables. These tools, and others, are available through the HAO Portal website (http://portal.hymao.org). We conclude by discussing the future of the HAO with respect to digital publication, cross-taxon ontology alignment, the advent of semantic phenotypes, and community-based curation.Katja C. Seltmann... Andrew D. Austin... John T. Jennings... et al

    Dictator Games: A Meta Study

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