ENDOCRINE REGULATION OF SEXUALLY DIMORPHIC DEVELOPMENT

睾酮(T)在脊椎动物两性异形的成体表达和维持中起着重要作用。然而，成年男性和女性对T操作的反应并不总是相同的。有时这些两性二态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普遍作用尚不清楚。本研究将验证以下假设：发育过程中T暴露的性别差异组织了在成年蜥蜴（Anolis carolinensis）中观察到的性别差异；在这个物种中，激素对大脑发育和行为的调节是完全未知的。首先，由于T暴露可能是由于母体卵黄T沉积，卵黄T将在雄性和雌性卵子中被记录下来。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（以及它是否从母体传递到卵黄）和胚胎T的合成和代谢。第三，将通过用T、抗雄激素氟他胺或适当的对照剂处理卵或幼鱼来评估T暴露对发育的影响。然后，将记录性伴侣和异性恋伴侣之间的行为相互作用，以确定治疗对男性典型行为发展的影响，并对与男性典型行为相关的大脑和周围结构进行表征。

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.