Biochemical and molecular characterization of an original master sex determining gene in salmonids

• Main Author: Bertho, Sylvain
• Other Authors: Laboratoire de Physiologie et Génomique des Poissons (LPGP), Institut National de la Recherche Agronomique (INRA)-Structure Fédérative de Recherche en Biologie et Santé de Rennes ( Biosit : Biologie - Santé - Innovation Technologique ), Agrocampus Ouest, Universitätsbibliothek (Wurtzbourg, Allemagne), Manfred Schartl, Yann Guiguen
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: HAL CCSD 2016
• Subjects: Sex development; Sex determination pathways; SdY Foxl2; Salmonids; Développement du sexe; Voies de détermination du sexe; Salmonidés; [SDV.BA]Life Sciences [q-bio]/Animal biology; Atlantic salmon
• Online Access: https://theses.hal.science/tel-01686524; https://theses.hal.science/tel-01686524/document; https://theses.hal.science/tel-01686524/file/pdf2star-1516179696-pdfa_G7UO3xZaBertho.pdf

Sexual development is a fundamental and versatile process that shapes animal morphology, physiology and behavior. The underlying developmental process is composed of the sex determination and the sex differentiation. The initial triggers are often genetics called sex determining genes. To date, among the known sex determining genes, three gene families namely sox, dmrt and TGF-ß factors govern this developmental program. As exception to this rule, sdY “sexually dimorphic on the Y” does not belong to one of these families as it comes from the duplication / evolution of an ancestor gene related to immunity, i.e., the interferon related factor 9, irf9.sdY is the master sex determining gene in salmonids, a group of fishes that include species such as rainbow trout and Atlantic salmon. The present study was aimed to firstly characterize the features of SdY protein. Results indicate that SdY is predominantly localized in the cytoplasm, composed of a ß-sandwich core surrounded by three a-helices as well specific characteristics conferring a putative protein-protein interaction site. Secondly, the study was aimed to understand how SdY could trigger testicular differentiation. Altogether results propose that SdY would trigger testicular differentiation in salmonids by interacting with a prominent female factor. Le développement du sexe est un processus fondamental et versatile qui forme la morphologie, la physiologie et le comportement des animaux. Le processus de développement sous-jacent est composé de la détermination et de la différentiation du sexe. Les mécanismes de détermination du sexe sont souvent génétiques et nommés gènes de détermination du sexe. A l’heure actuelle, parmi les gènes de détermination connus, trois familles de gènes nommément sox, dmrt and les facteurs TGF-ß gouvernent ce processus de développement.Comme exception à cette règle, sdY « sexually dimorphic on the Y » n’appartient à aucune de ces familles puisqu’il provient d’une duplication/évolution d’un gène ancestral de l’immunité, ...