Androgen-glucocorticoid Mediation of Behavioral Variation

了解行为和形态变异的生理基础是生物学的主要目标。然而，个体之间的许多变化的连续性往往使这类研究变得困难。这项研究将利用太阳鱼来探索两种不同类型的雄性的存在：一种是典型的双亲雄性类型，另一种是表现出男性和女性典型特征马赛克的绿帽子雄性。这两种类型的雄性之间的形态差异与生殖行为的差异密切相关，两种类型的雄性都具有繁殖能力。该项目将开始对雄激素和糖皮质激素在男性行为和形态变异表达中的作用及其相互作用进行系统的生化和行为检测。这些激素在脊椎动物中被认为是生殖行为的重要媒介，并在从各种环境刺激中传递信息方面发挥核心作用。这些研究将检验假设，即这两种类型的男性之间的行为差异与类固醇激素作用的两个重要组成部分的差异有关。这些研究将确定1)参与雄激素和糖皮质激素代谢的主要酶的活性，2)记录该酶和相关酶的组织特异性活性的形态和性别差异，3)记录在大脑和其他组织中雄激素和糖皮质激素受体以及这两种类固醇生成酶的表达，以及4)确定形态对标准化应激源的敏感性是否不同。由于许多行为背后的神经内分泌机制是保守的，拟议中的太阳鱼研究结果应该广泛适用于脊椎动物。该项目将为学生提供研究培训，该项目将神经内分泌研究与野外动物行为研究相结合，以了解行为背后的生理机制的演变。

Understanding the physiological bases of behavioral and morphological variation is a major goal in biology. However, the continuous nature of much of the variation among individuals often makes such study difficult. This research will use sunfish to exploit the existence of two distinct types of males: a "typical" parental male type and a cuckolder male that exhibits a mosaic of male- and female-typical characters. Morphological differences between the two types of males are tightly correlated with divergence in reproductive behavior and both types of males are reproductively competent. This project will begin a systematic biochemical and behavioral examination of the role of androgens and glucocorticoids, and their interactions, in the expression of male behavioral and morphological variation. These hormones are known across vertebrates to be important mediators of reproductive behavior and to play a central role in transducing information from various environmental stimuli. These studies will test hypotheses that differences in behavior between the two types of males are related to differences in two important components of steroid hormone action. The studies will determine 1) the activity of a major enzyme involved in androgen and glucocorticoid metabolism, 2) document morph and sex differences in tissue-specific activity of this and a related enzyme, 3) document in the brain and other tissues the expression of androgen and glucocorticoid receptors and these two steroidogenic enzymes, and 4) determine whether morphs differ in their sensitivity to a standardized stressor. Because many neuroendocrine mechanisms underlying behavior are conserved, the findings from the proposed studies of sunfish should be broadly applicable across vertebrates. The project will provide research training for students in a research program that integrates neuroendocrine studies with studies of behavior of animals in the field to understand the evolution of physiological mechanisms underlying behavior.