Temperature--Not Chromosomes--Determines the Sex of Certain Lower Vertebrates

与哺乳动物和鸟类的性染色体系统不同，许多爬行动物的性别是由卵的孵化温度决定的（温度依赖性性别决定，简称TSD）。TSD下的性别决定也可以通过人工应用特定的类固醇激素来控制，从而消除温度的影响。拟议的工作是在患有创伤后应激障碍的海龟中研究这种相互作用。这项研究有两个具体目的。第一个目标是通过(i)定位温度敏感窗口期间的关键酶，以及（ii）利用最近发现的外源雄激素可以导致男性发育，进一步研究TSD的生理基础。第二个目标是将我们的研究扩展到TSD/HSD的分子生物学领域，以识别、绘制和量化发育中的胚胎中的类固醇激素受体。总之，这些研究将有助于概括和统一解剖、生理和分子观察。这里提出的基础研究可以应用于濒危爬行动物的保护。

In contrast to the sex chromosome systems of mammals and birds, the sex of many reptiles is determined by the incubation temperature of the egg (temperature-dependent sex-determination, or TSD). Sex determination under TSD can also be controlled by the artificial application of specific steroid hormones, whereby the effects of temperature are overridden. The proposed work pursues this interplay in a turtle with TSD. The study has two specific aims. The first aim is to study further the physiological bases of TSD by (i) localizing key enzymes during the temperature-sensitive window, and (ii) capitalize on a recent discovery that exogenous androgen can cause male development. The second aim extends our line of research into the molecular biology of TSD/HSD to identify, map, and quantify steroid hormone receptors in the developing embryo. Together these studies will serve to generalize and unite anatomical, physiological, and molecular observations. The basic research proposed here has applications to the conservation of endangered reptiles.