动物性别决定机制可归类为基因型性别决定（GSD）和环境型性别决定（ESD）两大类，温度依赖型性别决定（TSD）是ESD的常见形式。到目前为止，GSD与TSD的进化过程仍然是“科学之谜”。逆转缺失进化假说是对这一进化过程较为广泛认同的解释，然而支持依据较缺乏。此前在GSD物种鬃狮蜥的研究中发现，ZZ型个体性别逆转后与正常ZZ雄性交配，其后代性别比例呈明显的TSD特征，为上述假说提供了有力证据。在此基础上我们考虑，若在TSD物种的胚胎性腺中过表达GSD物种的雄性关键基因SRY，是否可以使胚胎性别比例呈GSD模式？Sry基因在TSD与GSD的进化过程中所起的分子生物学机制是什么？由此我们选取分别为TSD和GSD的近缘物种中华草龟和越南粗颈龟，在草龟胚胎中过表达Sry，观察性别相关基因表达情况及后代性别表型，结合生物信息学方法分析，阐释Sry基因在龟鳖动物性别决定模式进化中的分子机制。

Sex determination include genetic-dependent sex determination (GSD) and environment-dependent sex determination (ESD), Temperature dependent sex determination (TSD) is the common form of ESD. Evolution between GSD and TSD is still an “enigma”. Sex-reversal evolution hypothesis is plausible, but lack of proofs. A research found that in the dragon lizards (GSD), ZZ embryos could sex reversed at high temperature, whose offsprings with ZZ males exhibiting obvious TSD pattern. This finding provides strong evidence for the hypothesis. So we consider how does the TSD embryos could develop if SRY gene from GSD species was over-expressed in them. Based on this assumption we select Chinemys reevesiis and Siebenrockiella crassicollis as target species. After over-expressed Sry in Chinemys reevesiis, expression of sex genes and gonad phenotypes was examined, combined with bioinformatics analysis, the role of Sry in the evolution of sex determining mechanism could be elucidated.