Department of Biology, University of Ottawa, Centre for Advanced Research in Environmental Genomics, Ottawa, ON, Canada K1N 6N5.
Mol Cell Endocrinol. 2011 Jan 1;331(1):143-9. doi: 10.1016/j.mce.2010.09.004. Epub 2010 Sep 15.
In amphibians, the main role of thyroid hormones (THs) is to regulate metamorphosis; however, there is evidence that THs also affect gonadal sexual differentiation. In this study, Silurana (Xenopus) tropicalis tadpoles were exposed to triiodothyronine (T3; 0, 0.5, 5 and 50 nM), the bioactive form of THs for 48h. Real-time RT-PCR analyses in the gonad-mesonephros complex (GMC) revealed that TH- and androgen-related genes were positively regulated, while estrogen receptor β was negatively regulated by T3. Together, these results are in agreement with the masculinizing effect of THs in amphibians. Profiles of TH- and sex steroid-related genes in the GMC during metamorphosis of S. tropicalis suggest that THs are important regulators of sex steroid-related gene expression in the GMC. This study provides evidence that the GMC is a target of THs but that a complex interplay exists between THs and sex steroids during gonadal sexual development.
在两栖动物中，甲状腺激素（THs）的主要作用是调节变态发育；然而，有证据表明 THs 也会影响性腺性别分化。在这项研究中，热带爪蟾（Xenopus）蝌蚪在三碘甲状腺原氨酸（T3；0、0.5、5 和 50 nM）中暴露 48 小时，这是 TH 的生物活性形式。在性腺-中肾复合体（GMC）中的实时 RT-PCR 分析表明，TH 和雄激素相关基因被正向调节，而雌激素受体β则被 T3 负向调节。总的来说，这些结果与 TH 在两栖动物中的雄性化作用一致。在热带爪蟾变态过程中 GMC 中的 TH 和性类固醇相关基因的图谱表明，TH 是 GMC 中性类固醇相关基因表达的重要调节剂。本研究提供的证据表明，GMC 是 TH 的靶标，但在性腺性发育过程中，TH 和性类固醇之间存在复杂的相互作用。
