RPG: Investigation of the Androgenic Basis for Male-Like Females in the Salamander Genus Aneides

9306523 Staub本研究计划资助的目的是描述几种蝾螈属雌性正常表达雄性样第二性征的内分泌机制。该项目验证了一种假设，即在一些种类的雌鸟中，这些雄性特征的表达是相对于缺乏这些特征的雌鸟，靶组织中循环血浆雄激素或雄激素受体水平较高的结果。为了实现这一目标，计划进行以下研究：1)记录男性和女性颌骨肌肉组织的第二性征，2)表征男性和女性颌骨肌肉组织中的雄激素受体，以及3)测定男性和女性循环血浆雄激素和雌激素水平。结果将在系统发育框架内进行分析，目的是了解内分泌变异如何解释在Aneides属内表达的戏剧性形态变异。在某些种类的蝾螈中，雌性表现出与雄性相似的特征，比如下巴肌肉组织增大。本研究的目的是描述这些特征在蝾螈属几种雌性物种中表达的激素基础。该计划测试了这样一个假设，即与缺乏这些特征的女性相比，女性的这些雄性特征的表达是由于下颌肌肉组织中雄激素（如睾酮）或雄激素受体水平较高的结果。该研究1)比较了男性和女性颌骨肌肉组织，2)检查了男性和女性颌骨肌肉组织中雄激素受体的结合水平，3)调查了男性和女性循环性激素（雄激素和雌激素）的水平。拟议的项目的主要意义在于，它将提供关于雄激素在正常女性特征发展中的作用的资料，这一作用相对来说尚未得到探索。＊＊＊

9306523 Staub The goal of this research planning grant is to describe the endocrinological mechanisms underlying the normal expression of male-like secondary sexual characteristics in females of several species in the salamander genus Aneides. The project tests the hypothesis that the expression of these male-like traits in females of several species of Aneides is a consequence of higher levels of circulating plasma androgens or androgen receptors in target tissues relative to females which lack these traits. To accomplish this, the following studies are planned: 1) documentation of the secondary sexual characteristics of the jaw musculature of males and females, 2) characterization of the androgen receptors in the jaw musculature of males and females, and 3) determination of levels of circulating plasma androgens and estrogens in males and females. Results will be analyzed in a phylogenetic framework with the goal of understanding how endocrinological variation can explain the dramatic morphological variation expressed within the genus Aneides. In some salamander species, females express male-like traits, such as enlarged jaw musculature. The goal of the proposed research is to describe the hormonal basis of the expression of these traits in females of several species in the salamander genus Aneides. The proposed project tests the hypothesis that the expression of these male-like traits in females is a consequence of higher levels of androgens (e.g. testosterone) or androgen receptors in the jaw musculature relative to females which lack these traits. The proposed research 1) compares male and female jaw musculature, 2) examines levels of androgen receptor binding in the jaw musculature of males and females, and 3) surveys levels of circulating sex hormones (androgens and estrogens) in males and females. The primary significance of the proposed project is that it will provide information on the role of androgens in the development of normal female characteristics, a role that has remained relatively unexplored. ***