Molecular characterization of estrogen receptor genes in Gobiocypris rarus and their expression upon endocrine disrupting chemicals exposure in juveniles

作者：Wang, Houpeng; Wang, Jingjing; Wu, Tingting; Qin, Fang; Hu, Xiaoqi; Wang, Lihong; Wang, Zaizhao^*

来源：Aquatic Toxicology, 2011, 101(1): 276-287.

DOI：10.1016/j.aquatox.2010.10.009

• Estrogen receptor
• Gobiocypris rarus
• Endocrine disrupting chemicals
• Quantitative real-time PCR

Estrogens play an important role in many physiological processes of vertebrates, mediated by estrogen receptors (ERs). The full length of the cDNAs for ER alpha, ER beta 1, and ER beta 2 were isolated and characterized from Gobiocypris rarus. G. rarus ERs shared the highest amino acid identities with counterparts of three cyprinidae species (Pimephales promelas ER alpha: 91.1%, Rutilus rutilus ER beta 1: 92.9%, Tanichthy albonubes ER beta 2: 93.5%). The phylogenic tree of vertebrate ERs indicates G. rams ER isoforms are more related to counterparts of cyprinidae species. The expression of ER alpha mRNA was high in gonad and liver. The ER beta 1 transcript was the highest in the liver of female fish and was evenly high in the liver, testis and intestine in male. The ER beta 2 transcript was high in liver, gonad, and intestine. G. rams juvenile at 34 days post fertilization were exposed for 3 days to endocrine disrupting chemicals including 17 alpha-ethynylestradiol (EE2), 4-nonylphenol (NP) and bisphenol A (BPA). ER mRNA expression following the xenoestrogens' exposure was analyzed by quantitative real-time PCR EE2 exposure at 0.01, 0.1 and 1 nM significantly up-regulated ER alpha transcript. ER beta 1 mRNA expression was suppressed by EE2 at all concentrations. However ER beta 2 transcript had opposite response to EE2 at low and high concentrations (up-regulation at 0.1 nM, down-regulation at 1 nM). Except a weak increase of ER alpha at 10 nM EE2, varying decrease of three ER transcripts was resulted in by NP at 10,100 and 1000 nM. ER alpha transcript was significantly up-regulated by BPA at 10 nM. A non-significant weak increase in ER beta 1 mRNA expression was caused by 1 nM BPA. However 1 nM and 10 nM BPA exposures resulted in significant and non-significant decrease ER beta 2 transcript, respectively. The BPA exposures at other concentrations almost had no effect on the ER transcripts. Vitellogenin (Vtg) mRNA expression profiling following exposure to three xenoestrogens indicated that Vtg transcript is a sensitive biomarker of the juvenile G. rarus at 34 dpf to the EDCs, especially to EE2. These results combined suggest that the ER genes are not modulated in the same manner by EE2. NP, and BPA and that ERs may not contribute equally to the transcriptional regulation of genes involved in fish development and reproduction.

• 出版日期2011-1-17
• 单位西北农林科技大学