title: Müllerian inhibiting substance in the caudate amphibian Pleurodeles waltl.
abstract: Müllerian inhibiting substance (MIS, also known as anti-Müllerian hormone), is a key factor of male sex differentiation in vertebrates. In amniotes, it is responsible for Müllerian duct regression in male embryos. In fish, despite the absence of Müllerian ducts, MIS is produced and controls germ cell proliferation during gonad differentiation. Here we show for the first time the presence of MIS in an amphibian species, Pleurodeles waltl. This is very astonishing because in caudate amphibians, Müllerian ducts do not regress in males. Phylogenetic analysis of MIS P. waltl ortholog revealed that the deduced protein segregates with MIS from other vertebrates and is clearly separated from other TGF-β family members. In larvae, MIS mRNA was expressed at higher levels in the developing testes than in the ovaries. In the testis, MIS mRNA expression was located within the lobules that contain Sertoli cells. Besides, expression of MIS was modified in the case of sex reversal: it increased after masculinizing heat treatment and decreased after estradiol feminizing exposure. In addition to the data obtained recently in the fish medaka, our results suggest that the role of MIS on Müllerian ducts occurred secondarily during the course of evolution.
authors.affiliation: Université de Lorraine, Faculté des Sciences et Technologies, Centre de Recherche en Automatique de Nancy (CRAN) Unité Mixte de Recherche 7039, Entrée 1B, Neuvième Étage, Boulevard des Aiguillettes, BP 239, F-54506 Vandoeuvre-lès-Nancy cedex, France. stephane.flament@univ-lorraine.fr.
authors.forename: Imane
authors.initials: I
authors.lastname: Al-Asaad
authors.forename: Dominique
authors.initials: D
authors.lastname: Chardard
authors.forename: Nathalie
authors.initials: N
authors.lastname: di Clemente
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Picard
authors.forename: Hélène
authors.initials: H
authors.lastname: Dumond
authors.forename: Amand
authors.initials: A
authors.lastname: Chesnel
authors.forename: Stéphane
authors.initials: S
authors.lastname: Flament
mesh_terms: D029845:Amphibian Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D054304:Anti-Mullerian Hormone / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D005260:Female; D018507:Gene Expression Regulation, Developmental; D017403:In Situ Hybridization; D007814:Larva / Q000254:growth & development / Q000378:metabolism; D008099:Liver / Q000254:growth & development / Q000378:metabolism; D008297:Male; D008675:Metamorphosis, Biological; D009095:Mullerian Ducts / Q000254:growth & development / Q000378:metabolism; D009924:Organ Culture Techniques; D010053:Ovary / Q000254:growth & development / Q000378:metabolism*; D010802:Phylogeny; D010999:Pleurodeles / Q000502:physiology*; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000378:metabolism; D012708:Sertoli Cells / Q000166:cytology / Q000378:metabolism; D012733:Sex Differentiation; D013737:Testis / Q000166:cytology / Q000254:growth & development / Q000378:metabolism*
chemical_list: D029845:Amphibian Proteins; D012333:RNA, Messenger; D054304:Anti-Mullerian Hormone