College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China.
Yangtze River Fisheries Research Institute, Chinese Academy of Fisheries Science, Wuhan 430223, China.
Genes (Basel). 2023 Jul 19;14(7):1466. doi: 10.3390/genes14071466.
The Chinese soft-shelled turtle, , is an important aquaculture species in China that exhibits distinct sexual dimorphism; male individuals are economically more valuable than females. In vertebrates, several R-spondin family proteins have been associated with sex differentiation mechanisms; however, their involvement in sex differentiation is unclear. Exogenous hormones such as estradiol (E2) also influence the sex differentiation of and induce sexual reversal. In the present study, we investigated the effects of E2 on the embryonic development of and the expression of () and (). We amplified and and analyzed their expression patterns in different tissues. Comparative analyses with protein sequences from other species elucidated that RSPO2 and RSPO3 sequences were conserved. Moreover, phylogenetic analysis revealed that RSPO2 and RSPO3 were closely related to these two proteins from other turtle species. Furthermore, and were highly expressed in the brain and gonads of adult turtles, with significantly higher expression in the ovaries than in the testes ( < 0.05). We also evaluated the expression of and after the administration of three concentrations of E2 (1.0, 5.0, and 10.0 mg/mL) to turtle eggs during embryonic development. The results revealed that E2 upregulated and , and the expression trends varied during different embryonic developmental stages (stages 13-20). These findings lay the groundwork for future investigations into the molecular mechanisms involved in the sex differentiation of Chinese soft-shelled turtles.
中华鳖，是中国重要的水产养殖物种，具有明显的性别二态性；雄性个体比雌性个体更具经济价值。在脊椎动物中，有几种 R 脊椎蛋白家族蛋白与性别分化机制有关；然而，它们在 性别分化中的参与情况尚不清楚。外源性激素如雌二醇（E2）也会影响 和诱导性反转。在本研究中，我们研究了 E2 对 胚胎发育的影响以及 （）和 （）的表达。我们扩增了 和 ，并分析了它们在不同组织中的表达模式。与其他物种的蛋白质序列进行比较分析表明， RSPO2 和 RSPO3 序列是保守的。此外，系统发育分析表明， RSPO2 和 RSPO3 与来自其他龟类的这两种蛋白质密切相关。此外， 和 在成年海龟的大脑和性腺中高度表达，卵巢中的表达显著高于睾丸（<0.05）。我们还评估了 E2（1.0、5.0 和 10.0 mg/mL）在胚胎发育过程中对海龟卵进行三个浓度给药后 和 的表达。结果表明，E2 上调了 和 ，表达趋势在不同的胚胎发育阶段（阶段 13-20）有所不同。这些发现为未来研究中华鳖性别分化的分子机制奠定了基础。
