| Co-Investigator(Kenkyū-buntansha) |
SATOU Yutaka Kyoto Univeristy, Department of Zoology, Assistant Professor, 大学院理学研究科, 助手 (40314174)
KURATANI Shigeru RIKEN CDB, Laboratory for Evolutionary Morphology, Team Leader, 発生・再生科学総合研究センター, チームリーダー (00178089)
AKASAKA Koji Univ. of Tokyo, Misaki Marine Biological Station, Director, 大学院理学研究科附属臨海実験所, 所長 (60150968)
HASEBE Mitsuyasu National Institue for Basic Biology, Laboratory of Evolutionary Biology, Professor, 生物進化研究部門, 教授 (40237996)
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| Research Abstract |
We have studied on the evolution of developmental systems of insects, vertebrates, echinoderms, and plants. Noji et al. found that in the developmental system of a cricket, Gryllus bimaculatus, anteroposterior patterning is principally controlled by posterior factors, such as Caudal. Since the developmental system of the cricket is more ancestral than that of Drosophila, this implies that the Drosophila anteroposterior patterning system, which is principally controlled by the anterior factor Bicoid, has evolved from the posterior dominant system similar to the cricket one. Sato et al. focused on an ascidian, Ciona intestinalis, and have conducted comprehensive description of expression profiles of the genes encoding transcription factors and signaling pathway components, along with analyzing their cDNA sequences. By their works, the Ciona gene catalog has been almost completely established and Ciona has become a model organism with the most integrated genome database in chordates. Kura
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tani et al. compared developmental systems between the soft-shelled turtle Pelodiscus sinensis and chicken. They have shown that the carapace ridge, which causes the turtle-specific topological shift of the ribs, is different from the Wolf ridge, a body wall structure in the late pharyngula of other amniotes. They also isolated Pelodiscus orthologs of regulatory genes expressed in the myotome in embryos of other vertebrates and found that Pelodiscus Myf5 has a characteristic deletion of four amino acids, different from its orthologs in chicken, mouse, and Xenopus, implying that such a molecular evolutionary event occurred specifically in the turtle- lineage. Akasaka et al. studied the developmental system of echinoderms using a sea urchin Hemicentrotus pulcherrimus and phylogentically the most basal group of echinoderms, Metacrinus rotundas (stalked crinoid) and Oxycomanthus japonicus (unstalked crinoid). They analyzed mechanisms of micromere specification in the sea urchin, isolated sea urchin T-box genes involved in morphogenesis, and examined their expression patterns during embryogenesis. Hasebe et al. have analyzed MADS-box genes of mosses and green algae, which do not form floral organs, for the purpose of investigating the origin and evolution of floral homeotic genes. They found that in these plants, MADS-box genes are expressed in the oogonium and antheridium together with the egg and spermatozoid during their differentiation. These expression patterns suggest that the precursors of land plant MADS-box genes originally functioned in haploid reproductive cell differentiation and that the haploid MADS- box genes were recruited into a diploid generation through gene duplication during the evolution of land plants. Less
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