龟鳖类温度依赖型性别决定机制的研究进展  

Temperature-dependent Sex Determination in Turtles

作　　者：贺斌[1] 史海涛[1,2] 廖广桥[1] 

机构地区：[1]海南师范大学生命科学学院,海口571158 [2]中国科学院成都生物研究所,成都610041

出　　处：《动物学杂志》2009年第5期147-152,共6页Chinese Journal of Zoology

基　　金：海南省研究生创新科研课题(No.Hxwsy 2008-19);国家自然科学基金项目(No.30660026)

摘　　要：近几十年来,发现很多爬行动物具有温度依赖型性别决定机制(TSD),即性别分化取决于胚胎发育过程中温度敏感期(TSP)的环境温度高低。龟鳖类存在两种TSD模式,即低温产雄性、高温产雌性的TSDⅠa,低温、高温均产雌性而中间温度产雄性的TSDⅡ。TSD机制在生理水平的作用机制主要受到性腺类固醇激素的控制,温度通过影响芳香化酶和5α-还原酶的活性控制雌、雄激素转化,进而决定了个体的性别分化。在分子水平的研究发现:Sf1、Mis、Sox9、Dax1、Wt1和Dmrt1等基因的表达受到温度的影响,参与了龟鳖类性别分化。介绍了关于TSD的进化意义提出的假说,有待进一步验证。Temperature-dependent sex determination （TSD） has been studied extensively over the past several decades in a variety of reptiles. Sexual differentiation of gonads is sensitive to temperature during thermosensitive period （TSP） . Two patterns have been demonstrated in ehelonians： ① males from cool temperature while females from warm temperature （TSD I α） and ② females from both cool and warm temperatures, while males from intermediate temperature （TSD II ）. The possible mechanisms of TSD caused by sex steroid hormone levels have been studied. Several groups have provided direct support for the hypothesis that the physical stimulus of temperature is transduced into an endocrine signal that directs the sex-determination process： specifically, estrogens and their precursors, aromatizable androgens, stimulate the female-determining cascade and inhibit the male determining cascade. Preliminary results show that expression of Sf1, Mis, Sox9, Dax1, Wt1 and Dmrt1 is affected by temperature, which may be involved in sex determination.. Hypotheses on the evolutional significance of TSD are introduced, and each of these explanations remains partly but not fully plausible.

关 键 词：龟鳖类 温度依赖型性别决定 研究进展 

分 类 号：S917.4[农业科学—水产科学]