title: Cyp17a1 and Cyp19a1 in the zebrafish testis are differentially affected by oestradiol.
abstract: Oestrogens can affect expression of genes encoding steroidogenic enzymes in fish gonads. However, little information is available on their effects at the protein level. In this context, we first analysed the expression of key steroidogenic enzyme genes and proteins in zebrafish testis, paying attention also to other cell types than Leydig cells. Gene expression was analysed by quantitative PCR on fluorescence-activated cell-sorting fractions coupled or not to differential plating, while protein synthesis was studied by immunohistochemistry using specific antibodies against zebrafish Cyp17a1, Cyp19a1a and Cyp19a1b. Furthermore, we have evaluated the effect of oestrogen treatment (17β-oestradiol (E(2)), 10 nM) on the localization of these enzymes after 7 and 14 days of in vivo exposure in order to study how oestrogen-mediated modulation of their expression is linked to oestrogen effects on spermatogenesis. The major outcomes of this study are that Leydig cells express Cyp17a1 and Cyp19a1a, while testicular germ cells express Cyp17a1 and both, Cyp19a1a and Cyp19a1b. As regards Cyp17a1, both protein and mRNA seem to be quantitatively dominating in Leydig cells. Moreover, E(2) exposure specifically affects only Leydig cell Cyp17a1 synthesis, preceding the disruption of spermatogenesis. The oestrogen-induced suppression of the androgen production capacity in Leydig cells is a major event in altering spermatogenesis, while germ cell steroidogenesis may have to be fuelled by precursors from Leydig cells. Further studies are needed to elucidate the functionality of steroidogenic enzymes in germ cells and their potential role in testicular physiology.
authors.affiliation: INERIS, Direction des Risques Chroniques, Pôle VIVA, Unité d'écotoxicologie in vitro et in vivo, BP2, 60550 Verneuil-en-Halatte, France. nathalie.hinfray@ineris.fr
authors.forename: Nathalie
authors.initials: N
authors.lastname: Hinfray
authors.forename: Rafael Henrique
authors.initials: RH
authors.lastname: Nóbrega
authors.forename: Morgane
authors.initials: M
authors.lastname: Caulier
authors.forename: Damien
authors.initials: D
authors.lastname: Baudiffier
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Maillot-Maréchal
authors.forename: Edith
authors.initials: E
authors.lastname: Chadili
authors.forename: Olivier
authors.initials: O
authors.lastname: Palluel
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Porcher
authors.forename: Rüdiger
authors.initials: R
authors.lastname: Schulz
authors.forename: François
authors.initials: F
authors.lastname: Brion
mesh_terms: D000818:Animals; D001141:Aromatase / Q000235:genetics* / Q000378:metabolism; D004958:Estradiol / Q000494:pharmacology*; D004967:Estrogens / Q000494:pharmacology*; D015870:Gene Expression / Q000187:drug effects; D005854:Germ Cells / Q000187:drug effects / Q000201:enzymology; D007985:Leydig Cells / Q000187:drug effects / Q000201:enzymology; D008297:Male; D013091:Spermatogenesis / Q000187:drug effects / Q000502:physiology; D013254:Steroid 17-alpha-Hydroxylase / Q000235:genetics* / Q000378:metabolism; D013737:Testis / Q000187:drug effects* / Q000201:enzymology; D015027:Zebrafish / Q000235:genetics* / Q000378:metabolism; D029961:Zebrafish Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: D004967:Estrogens; D029961:Zebrafish Proteins; D004958:Estradiol; D001141:Aromatase; C440729:Cyp19a1a protein, zebrafish; D013254:Steroid 17-alpha-Hydroxylase