title: Neonatal expression of amh, sox9 and sf-1 mRNA in Caiman latirostris and effects of in ovo exposure to endocrine disrupting chemicals.
abstract: Caiman latirostris is a reptilian species that exhibits temperature-dependent sex determination (TSD). Male-to-female sex reversal can be achieved after in ovo estrogen/xenoestrogen exposure. This is known as hormone-dependent sex determination (HSD). The amh, sox9 and sf-1 genes are involved in sex determination, sex differentiation, and steroidogenesis. The aims of this study were: (a) to establish the expression patterns of amh, sox9 and sf-1 mRNA in the gonad-adrenal-mesonephros (GAM) complexes of neonatal TSD-male and TSD-female caimans, (b) to compare the expression of these genes between TSD-females and HSD-females (born from E2-exposed eggs incubated at the male-producing temperature) and (c) to evaluate whether in ovo exposure to a low dose of E2 or bisphenol A (BPA) or to a high dose of endosulfan (END) modifies amh, sox9 or sf-1 mRNA expressions in neonatal males. The mRNA expressions of amh, sox9 and sf-1 in GAM complexes from TSD-males and TSD-females and from HSD-females were quantitatively compared by RT-PCR. A sexually dimorphic pattern of amh and sox9 mRNA expression was found, with a higher expression in TSD-males than in TSD-females. sf-1 mRNA did not differ between TSD-males and TSD-females. HSD-females exhibited a higher expression of sox9 than TSD-females. In males, increased mRNA expression of sex-determining genes was observed after in ovo exposure to END. E2 decreased sox9 but increased sf-1 mRNA expression. Changes induced by BPA were evident although not significant. These results provide new insights into the potential mechanisms that lead to the gonadal histo-functional alterations observed in caimans exposed to contaminated environments.
authors.affiliation: Laboratorio de Endocrinología y Tumores Hormonodependientes, School of Biochemistry and Biological Sciences, Universidad Nacional del Litoral, Santa Fe, Argentina.
authors.forename: Milena
authors.initials: M
authors.lastname: Durando
authors.forename: Laura
authors.initials: L
authors.lastname: Cocito
authors.forename: Horacio A
authors.initials: HA
authors.lastname: Rodríguez
authors.forename: Jorgelina
authors.initials: J
authors.lastname: Varayoud
authors.forename: Jorge G
authors.initials: JG
authors.lastname: Ramos
authors.forename: Enrique H
authors.initials: EH
authors.lastname: Luque
authors.forename: Mónica
authors.initials: M
authors.lastname: Muñoz-de-Toro
mesh_terms: D000489:Alligators and Crocodiles / Q000378:metabolism*; D000818:Animals; D001559:Benzhydryl Compounds / Q000633:toxicity; D052244:Endocrine Disruptors / Q000633:toxicity*; D004726:Endosulfan / Q000633:toxicity; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects / Q000235:genetics; D008297:Male; D010636:Phenols / Q000633:toxicity; D012333:RNA, Messenger / Q000235:genetics*; D055758:SOX9 Transcription Factor / Q000235:genetics*; D054339:Steroidogenic Factor 1 / Q000235:genetics*; D013737:Testis / Q000187:drug effects / Q000378:metabolism; D000098826:Bisphenol A Compounds
chemical_list: D001559:Benzhydryl Compounds; D052244:Endocrine Disruptors; D004726:Endosulfan; D010636:Phenols; D012333:RNA, Messenger; D055758:SOX9 Transcription Factor; D054339:Steroidogenic Factor 1; C006780:bisphenol A; D000098826:Bisphenol A Compounds
keywords: 17β-estradiol; AMH; BPA; Bisphenol A; Crocodilian; E(2); EDCs; END; Endosulfan; GAM; HSD; M-MLV; Moloney Murine Leukemia Virus; SRY; SRY-like HMG box; Sex-determining genes; Sexual dimorphism; TSD; TSP; Temperature-dependent sex determination; anti-Müllerian hormone; bisphenol A; endocrine-disrupting chemicals; endosulfan; gonad-adrenal-mesonephros; hormone-dependent sex determination; sex-determining region of the Y chromosome; sf-1; sox9; steroidogenic factor-1; temperature-dependent sex determination; thermosensitive-period