College of Biological and Environmental Engineering, Zhejiang University of Technology, Hangzhou, China.
Aquat Toxicol. 2011 Jan 17;101(1):254-60. doi: 10.1016/j.aquatox.2010.10.005. Epub 2010 Oct 20.
Temperature and photoperiod are the two most important environmental cues in the regulation of the annual cycles of circulating sex steroid hormones and reproduction in fish. Thus, these variables may alter the endocrine disruption effects induced by environmental endocrine disrupting chemicals (EDCs). In the present study, we found that the temperature and photoperiod significantly influence the transcription of the estrogen-responsive genes, vitellogenin1 (Vtg1), vitellogenin2 (Vtg2) and estrogen receptor-α (ERα) after a 7-day exposure to environmentally relevant concentrations of 17β-estradiol (E2) and nonylphenol (NP) in different developmental stages of Japanese medaka. In general, gene transcription levels increased as temperature and photoperiod length increased. The Vtg1 mRNA levels in 20 °C-12L group were 10-30 times higher than those in 10 °C-10 L group when larvae, both sexes of juvenile or male adult medaka were exposed to 50 ng/L E2. In addition, juveniles of both sexes and adult males were more sensitive to temperature and photoperiod changes than larval and adult female medaka. Specifically, two-way analysis indicated that both E2 and NP-mediated induction of Vtg1 mRNA (the most effective) expression interacted with environmental cues (temperature and photoperiod) and exposure concentrations in a developmental stage- and sex-specific manner. The results obtained in the present study demonstrate that the endocrine disrupting effects of environmental chemicals can be modified by seasonality and life stage in which the exposure occurs and that Vtg1 transcription is a good biomarker to evaluate these interactions.
温度和光周期是调节鱼类循环性激素和生殖的年度周期的两个最重要的环境线索。因此，这些变量可能会改变环境内分泌干扰化学物质（EDCs）引起的内分泌干扰效应。在本研究中，我们发现温度和光周期显著影响雌激素反应基因 vitellogenin1（Vtg1）、vitellogenin2（Vtg2）和雌激素受体-α（ERα）的转录，在不同发育阶段的日本青鳉中，经过 7 天暴露于环境相关浓度的 17β-雌二醇（E2）和壬基酚（NP）后。一般来说，基因转录水平随着温度和光照长度的增加而增加。当幼虫、雌雄幼鱼或雄性成鱼暴露于 50ng/L E2 时，20°C-12L 组的 Vtg1 mRNA 水平比 10°C-10L 组高 10-30 倍。此外，雌雄幼鱼和成鱼雄性对温度和光周期变化比幼鱼和成年雌性青鳉更敏感。具体而言，双向分析表明，E2 和 NP 介导的 Vtg1 mRNA 诱导（最有效）表达与环境线索（温度和光周期）以及暴露浓度在发育阶段和性别特异性方面相互作用。本研究的结果表明，环境化学物质的内分泌干扰效应可以通过发生暴露的季节性和生活阶段来改变，并且 Vtg1 转录是评估这些相互作用的良好生物标志物。
