Responses of gonadal transcriptome and physiological analysis following exposure to 17α-ethynylestradiol in adult rare minnow Gobiocypris rarus.

17α-ethynylestradiol (EE2), a synthetic estrogen commonly used in the oral contraceptive pills, disrupts the sexual differentiation, gonadal development and reproduction in aquatic species. Nowadays aquatic species and even humans still have the potential risks of exposure to EE2. However, the mechanism of EE2 endocrine disruption is still unclear. Aiming to elucidate molecular mechanisms, we analyzed transcriptome profiling of gonads, gonadal histology and the sex steroid hormones in response to EE2 in G. rarus. Through this study, we obtained eight RNA-Seq libraries upon EE2 exposure, and found some key genes and pathways in correlation with the disruption effects of EE2. We found EE2 could disrupt oocyte development and spermatogenesis in adult G. rarus, and EE2 has more obvious disruption effects on male G. rarus than females. Interestingly, EE2 was indicated to be an exogenous DPC-inducing agent and ppp2r3b was suggested to be a spermatogenesis candidate gene in rare minnow. The differential gene expressions of rps30, samp9, ppp2r3b and spartan upon EE2 exposure suggest EE2's disruption effects on gonads could attribute to altered pathways of translation, ribosome biogenesis and cell division.