title: Female-enriched and thermosensitive expression of steroidogenic factor-1 during gonadal differentiation in Pleurodeles waltl.
abstract: In the urodele amphibian Pleurodeles waltl, sex differentiation is genetically controlled, that is, ZZ male vs ZW female, but may be influenced by temperature, which induces a female-to-male sex reversal. We investigated whether steroidogenic factor 1 (SF-1) could be involved in Pleurodeles sex differentiation or in temperature-dependent sex reversal by cloning a Pleurodeles SF-1 cDNA and examining its developmental expression. The 468-amino-acid deduced protein is highly conserved in comparison with other species. In ZZ and ZW control larvae, SF-1 mRNA is detected at the first stage of the thermosensitive period (TSP) in the gonad-mesonephros-interrenal complex (GMI). By the end of TSP at stage 55, SF-1 is expressed in the gonad (Gd) and in the mesonephros-interrenal (MI) both in ZZ and ZW larvae. During this stage, a transient, ZW-specific increase of SF-1 transcription occurs not only in Gd but also in MI, this increase starting earlier in Gd than in MI. Therefore, in P. waltl, an SF-1 upregulation occurs after the onset of the ovarian-specific increase of aromatase mRNA expression. At the end of metamorphosis, the SF-1 transcription level in Gd and MI is nearly the same in both ZZ and ZW larvae. Besides, after long-term heat treatment leading to sex reversal, SF-1 mRNA upregulation is not observed in ZW larvae, in either Gd or MI. However, SF-1 expression is not decreased after a 48-h heat shock applied at the end of the TSP, suggesting that temperature has no inhibitory effect by itself in long-term heat treatment. Estradiol benzoate treatments show that, at the end of the TSP, SF-1 gene transcription could be controlled by the estrogen level. This is in accordance with the female-enriched SF-1 expression and the decreased SF-1 expression following long-term, sex-reversing heat treatment, which is known to decrease aromatase expression and activity. Thus, it is unlikely that SF-1 is directly involved in Pleurodeles temperature-dependent sex reversal.
authors.affiliation: EA 3442: Aspects Cellulaires et Moléculaires de la Reproduction et du Développement, Université Henri Poincaré-Nancy 1, Faculté des Sciences, BP239, Boulevard des Aiguillettes, 54506 Vandoeuvre lès nancy CEDEX, France.
authors.forename: S
authors.initials: S
authors.lastname: Kuntz
authors.forename: D
authors.initials: D
authors.lastname: Chardard
authors.forename: C-I
authors.initials: CI
authors.lastname: Ko
authors.forename: H
authors.initials: H
authors.lastname: Dumond
authors.forename: M
authors.initials: M
authors.lastname: Ducatez
authors.forename: M
authors.initials: M
authors.lastname: Callier
authors.forename: S
authors.initials: S
authors.lastname: Flament
authors.forename: A
authors.initials: A
authors.lastname: Chesnel
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D005260:Female; D018398:Homeodomain Proteins / Q000737:chemistry / Q000235:genetics*; D008297:Male; D008969:Molecular Sequence Data; D010999:Pleurodeles / Q000378:metabolism* / Q000502:physiology; D012333:RNA, Messenger / Q000235:genetics; D018160:Receptors, Cytoplasmic and Nuclear / Q000737:chemistry / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D012733:Sex Differentiation; D054339:Steroidogenic Factor 1; D014157:Transcription Factors / Q000737:chemistry / Q000235:genetics*
chemical_list: D017931:DNA Primers; D018398:Homeodomain Proteins; D012333:RNA, Messenger; D018160:Receptors, Cytoplasmic and Nuclear; D054339:Steroidogenic Factor 1; D014157:Transcription Factors