Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8319161 | Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology | 2014 | 8 Pages |
Abstract
The synthetic estrogen 17α-ethinyl estradiol (EE2) disturbs reproduction and causes gonadal malformation in fish. Effects on the transcription of genes involved in gonad development and function that could serve as sensitive biomarkers of reproductive effects in the field is, however, not well known. We have studied mRNA expression in testes and liver of adult zebrafish (Danio rerio) males treated with 0, 5 or 25 ng/L EE2for 14 days. qPCR analysis showed that the mRNA expression of four genes linked to zebrafish male sex determination and differentiation, Anti-Mullerian Hormone, Double sex and mab-related protein, Sry-related HMG box-9a and Nuclear receptor subfamily 5 group number 1b were significantly decreased by 25 ng/L, but not 5 ng/L EE2 compared with the levels in untreated fish. The decreased transcription was correlated with a previously shown spawning failure in these males (Reyhanian et al., 2011. Aquat Toxicol 105, 41-48), suggesting that decreased mRNA expression of genes regulating male sexual function could be involved in the functional sterility. The mRNA level of Cytochrome P-45019a, involved in female reproductive development, was unaffected by hormone treatment. The transcription of the female-specific Vitellogenin was significantly induced in testes. While testicular Androgen Receptor and the Estrogen Receptor-alpha mRNA levels were unchanged, Estrogen receptor-beta was significantly decreased by 25 ng/L EE2. Hepatic Estrogen Receptor-alpha mRNA was significantly increased by both exposure concentrations, while Estrogen Receptor-beta transcription was unaltered. The decreased transcription of male-predominant genes supports a demasculinization of testes by EE2 and might reflect reproductive disturbances in the environment.
Keywords
ER-αsex determining region Y18S RNAcyp19aDMY17α-ethinyl estradiolSOX9ADMRT1ER-βEE2qPCREDCVitellogeninSTPEndocrine disruptorsEstrogenAMHBiomarkerSewage treatment plantSex differentiationGene regulationSryendocrine disrupting chemicalAnti-Müllerian hormonequantitative real time polymerase chain reactionvtgGonadsZebrafishAndrogen ReceptorEstrogen receptor alphaEstrogen receptor beta
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Authors
Nasim Reyhanian Caspillo, Kristina Volkova, Stefan Hallgren, Per-Erik Olsson, Inger Porsch-Hällström,