College of Fisheries and Life Sciences, Shanghai Ocean University, Shanghai, 201306, China.
Institute of Animal Sex and Development, Zhejiang Wanli University, Ningbo, 315100, China.
Biol Reprod. 2023 Jun 9;108(6):988-996. doi: 10.1093/biolre/ioad033.
SOX8, which belongs to SOXE transcription factor subfamily together with SOX9, participates in sex differentiation and testicular development by enhancing the function of SOX9 in mammals. However, the functional role of SOX8 in sex differentiation has not yet been identified in any non-mammalian vertebrates. Here, we found in the Chinese soft-shelled turtle Pelodiscus sinensis that SOX8 exhibited male-specific higher expression from stage 14 to 18, the critical period of sex determination, prior to the onset of gonadal differentiation. In addition, SOX8 was rapidly down-regulated during male-to-female sex reversal induced by estradiol. Moreover, knockdown of SOX8 led to complete feminization of ZZ P. sinensis, determined by gonadal morphology and distribution of germ cells, as well as the down-regulation of testicular marker DMRT1 and the up-regulation of ovarian regulator FOXL2. In conclusion, this study provides evidence that SOX8 is a key regulator of early male differentiation in P. sinensis, highlighting the significance of the SOX family in reptile sex determination.
SOX8 属于 SOXE 转录因子亚家族，与 SOX9 一起参与性别分化和睾丸发育，通过增强 SOX9 在哺乳动物中的功能。然而，SOX8 在性分化中的功能作用在任何非哺乳动物脊椎动物中尚未被确定。在这里，我们在中华鳖 Pelodiscus sinensis 中发现，SOX8 在性别决定的关键时期，从第 14 期到第 18 期，即睾丸分化之前，表现出雄性特异性更高的表达。此外，SOX8 在雌激素诱导的雄性到雌性性别逆转期间迅速下调。此外，SOX8 的敲低导致 ZZ 中华鳖的完全雌性化，这可以通过性腺形态和生殖细胞的分布以及睾丸标记物 DMRT1 的下调和卵巢调节剂 FOXL2 的上调来确定。总之，这项研究提供了证据表明 SOX8 是 P. sinensis 早期雄性分化的关键调节剂，强调了 SOX 家族在爬行动物性别决定中的重要性。
