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7 juin 2019: 1 événement

  • Département Biologie Cellulaire

    Vendredi 7 juin 11:30-12:30 - James CASTELLI-GAIR HOMBRIA - CABD, Sevilla, Espagne

    Comparison of the trachea and the endocrine gland development of Drosophila as a model to study divergent evolution of organogenesis

    Résumé : We have discovered that, despite being functionally and morphologically different, the tracheae and the endocrine organs controlling insect metamorphosis are homologous structures that develop from a serially repeated structure. In the cephalic segments, JAK/STAT signalling collaborating with anterior Hox genes induces the metameric structure to develop into the endocrine glands required for moulting and metamorphosis. In the trunk segments, JAK/STAT signalling collaborating with central and posterior Hox genes induces the formation of respiratory trachea.
    The development of trachea and endocrine organs initiates with the invagination of the polarized epithelial cells. The morphological divergence occurs shortly after invagination, when activation of Snail in the endocrine primordia induces an epithelial to mesenchymal transition (EMT). New genetic evidence suggests that the head endoskeletal elements are also derived from the same metamerically repeated structure.
    Our data are important because : (1) they uncover the genetic and developmental mechanisms for ring gland morphogenesis and (2) indicate that the head endoskeleton, the respiratory tracheal organs and two main endocrine glands arose through a process of divergent evolution from an ectodermal repeated structure that lead to extremely different morphological and functional organs.

    Lieu : Bibliothèque - bâtiment 34 - campus de Gif-sur-Yvette

    En savoir plus : Département Biologie Cellulaire