Effects of ethinylestradiol and of an environmentally relevant mixture of xenoestrogens on steroidogenic gene expression and specific transcription factors in zebrafish.
In natural environments fish are exposed to endocrine disrupting compounds (EDCs) present at low concentrations and with different modes of actions. Here, adult zebrafish of both sexes were exposed for 21 days to an estrogenic mixture (Mix) of eleven EDCs previously quantified in Douro River estuary (Portugal) and to 100 ng/L 17α-ethinylestradiol (EE2) as positive control. Vitellogenin mRNA and HSI in males confirmed both exposure regimes as physiologically active. Potential candidates for estrogenic disturbance of steroidogenesis were identified (StAR, 17β-HSD1, cyp19a1), but Mix only affected cyp19a1 in females. Significant differences in the response of FSHβ, cypa19a2, 20β-HSD were observed between EE2 and Mix. Mtf-1 and tfap2c transcription factor binding sites were discovered in the putative promoter regions and corresponding transcription factors were found to be differentially expressed in response to Mix and EE2. The results suggest that "non-classical effects" of estrogenic EDC in fish are mediated via transcription factors.
Laboratory of Cellular, Molecular and Analytical Studies (LECEMA), Interdisciplinary Centre of Marine and Environmental Research (CIIMAR), CIMAR Associated Laboratory (CIMAR LA), University of Porto (U.Porto), Rua dos Bragas 289, 4050-123 Porto, Portugal. rurbatzka@ciimar.up.pt
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D000818:Animals; D052244:Endocrine Disruptors / Q000633:toxicity; D004997:Ethinyl Estradiol / Q000633:toxicity*; D005260:Female; D015870:Gene Expression / Q000187:drug effects*; D006062:Gonadotropins / Q000235:genetics / Q000378:metabolism; D008297:Male; D012333:RNA, Messenger / Q000378:metabolism; D013256:Steroids / Q000378:metabolism; D014819:Vitellogenins / Q000235:genetics / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000633:toxicity; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism
D052244:Endocrine Disruptors; D006062:Gonadotropins; D012333:RNA, Messenger; D013256:Steroids; D014819:Vitellogenins; D014874:Water Pollutants, Chemical; D029961:Zebrafish Proteins; D004997:Ethinyl Estradiol