中文摘要：

环境雌激素对两栖动物的生殖内分泌干扰作用已引起关注,目前的研究主要集中在长期暴露对性腺分化和发育的影响.以雌二醇（E2,10 nmol·L-1）为模式化合物,以非洲爪蟾为实验动物,6月龄的幼蛙暴露6d,研究雌激素对性腺和输卵管形态以及性二态性基因表达的影响.结果发现,6d的E2暴露对精巢和卵巢的形态没有明显影响,但从组织学结构来看对卵和精子的发育有微弱的促进作用.E2能够明显地促进了雌性输卵管的发育,表现为输卵管变粗变弯曲.E2暴露显著抑制精巢和卵巢中性激素合成相关基因cyp11a1、3βHSD、Srd5α、ARO的表达,对cyp17的表达无影响,使脑中LHβ和FSHβ的表达下调;对性别分化和性腺发育相关基因Dax、AR、ERα、TFⅢA、TBPL2的表达均无影响,但能够促进卵巢中Sox3的表达;同时促进脑中Emi2的表达,抑制脑中Dmrt1的表达.因此,输卵管可作为敏感的形态指标,性腺中Srd5α、cyp11a1、3βHSD、ARO、Sox3和脑中LHβ、FSHβ、Dmrt1、Emi2可作为分子指标.以上结果可为后续建立评价化学品对两栖动物雌激素效应的短期试验方法提供参考.

英文摘要：

Reproductive endocrine disruption by concern. The research in the field was focused on development. In this study, Xenopus laevis frogs environmental estrogens in amphibians has aroused great effects of long-term exposure on gonadal differentiation and （6 month old） were exposed to 10 nmol· L^-1 estradiol （E2, a model compound） for six days to investigate the effects on gonadal and oviductive morphology as well as mRNA expression of sexually dimorphic genes. It was found that 6-day exposure to E2 had no significant effect on testicular and ovarian morphology, whereas it seemed to exhibit a weak promoting effect on egg and sperm development. E2 made oviducts widen and curve, exhibiting a promoting effect on oviductive develop- ment. Compared with the control, E2 exposure significantly inhibited expression levels of cypllal, 313HSD, Srd5ot and ARO, which are related to sex hormone synthesis and transformation, in testis and ovary, with no effect on the expression of cypl7. E2 also decreased LHI3 and FSHI3 expression in brain. Several genes that are related to sex differentiation and gonadal development, including Dax, AR, ERa, TFIIlA and TBPL2, were not affected by E2 at the transcriptional levels. By contrast, E2 significantly promoted Sox3 expression in the ovary and Emi2 in the brain, and inhibited Dmrtl expression in the brain. Therefore, oviductive morphology and the expression levels of Srd5α, cypllal, 313HSD, ARO and Sox3 in the gonad as well as LHI3, FSHI3, Dm- rtl and Emi2 in the brain can be used as sensitive endpoints. Our study can provide technical reference for developing a short-term assay for evaluating estrogenic effects of chemicals on amphibians