ENDOCRINE REGULATION OF SEXUALLY DIMORPHIC DEVELOPMENT

睾酮(T)在成体表达和维持不同脊椎动物类群中的性别二型性方面起着重要作用。然而，成年男性和女性对T操作的反应并不总是相同的。有时，这些性二型性是由于发育过程中T暴露的差异，但性腺类固醇在发育过程中的这种作用是否普遍存在尚不清楚。这项研究将检验这样一种假设，即在发育过程中暴露于T的性别差异会组织在成年蜥蜴(Anolis Carolinensis)身上观察到的性别差异；这种物种大脑和行为发育的荷尔蒙调节完全未知。首先，由于T暴露可能是由于母体卵黄T沉积造成的，因此将记录雄性和雌性卵子的卵黄T。其次，为了确定胚胎环境中T的来源，将记录整个排卵周期的母体血浆T(以及它是否从母亲传递到卵黄)和胚胎T的合成和代谢。第三，T暴露对发育的影响将通过用T、抗雄激素氟他胺或适当的对照组处理卵子或幼虫来评估。然后，双性恋和异性恋之间的行为互动将被记录下来，以确定治疗对男性典型行为发展的影响，并将描述与男性典型行为相关的大脑和外周结构。

Testosterone (T) plays a role in the adult expression and maintenance of sexual dimorphisms across vertebrate taxa. Adult males and females do not always respond the same way to T manipulation, however. Sometimes these sexual dimorphisms are due to differences in T exposure during development, but the ubiquity of this developmental role for gonadal steroids is unclear. This study will test the hypothesis that sex differences in T exposure during development organize sex differences observed in adults in a lizard (Anolis carolinensis); the hormonal regulation of the development of brain and behavior in this species is completely unknown. First, because T exposure may result from maternal yolk T deposition, yolk T will be documented for male and female eggs. Second, to determine the source of T in the embryonic environment, both maternal plasma T across the ovulatory cycle (and whether it passes from mother to yolk) and embryonic T synthesis and metabolism will be documented. Third, the effects of T exposure on development will be assessed by treatment of eggs or juveniles with T, the antiandrogen flutamide, or appropriate controls. Then, behavioral interactions between consexual and heterosexual pairs will be documented to determine treatment effects on the development of male-typical behavior, and the brain and peripheral structures associated with male-typical behavior will be characterized.