Doctoral Dissertation Research: Androgyny & Androgens in Females: Relating Hormones to the Evolution of Sexual Dimorphism

博士论文研究：雌雄同体

• 批准号: 0910036
• 负责人: Ellen Ketterson
• 金额: $ 1.47万
• 依托单位: Indiana University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-08-01 至 2012-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0910036&HistoricalAwards=false
• 关键词: Doctoral; Dissertation; Research; Androgyny; &amp

When the optimal phenotype differs by sex, the evolution of sex differences, or sexual dimorphism, is expected. In many species, however, the degree of dimorphism is mild, and numerous individuals express traits, e.g. body size or behavior, that fall between male and female norms. Females in this group, known as androgynous females, are of interest because they offer a natural experiment for understanding the sources and consequences of sexual dimorphism. Variation in hormone exposure, especially androgens like testosterone, is a primary mechanism for the development of sex differences in vertebrates. This variation may also mediate the expression of androgynous traits within a sex, leading to covariation among male-like traits, e.g. big females may also be aggressive females. If male-like females differ from typical females in survival or reproduction, the degree of sexual dimorphism may reduced or enhanced. This project seeks to determine whether the degree androgyny expressed in one trait (morphology or behavior) is related to the level of androgyny in other traits, which would indicate a common mechanism controlling trait expression. Additionally this project will strive to determine whether androgen exposure during development or in adulthood is driving this covariation, and also whether androgynous females vary from typical females in survival or reproductive success. Answers to these questions will inform our understanding of the potential links between social behavior, morphology and hormone exposure levels in females as well as the evolution of complex traits that are mediated by hormones. This work will be done with free-living songbirds and serve to train undergraduates to conduct research as part of training programs such as NSF's Research Experience for Undergraduates (REU) and Indiana University's Student Achievement in Research and Scholarship (STARS) programs.

当最佳表型因性别而不同时，期望性别差异或性二态性的演变。然而，在许多物种中，二态性的程度是温和的，许多个体表达了特征，例如身体大小或行为，介于男性和女性规范之间。该群体中的女性被称为雌雄同体，是感兴趣的，因为它们提供了一个自然的实验来理解性二态性的来源和后果。激素暴露的变化，尤其是像睾丸激素这样的雄激素，是脊椎动物性别差异发展的主要机制。这种变异还可以介导性别内雌雄同体的表达，从而导致男性状性状之间的协方差，例如大女性也可能是侵略性的女性。 如果男性样的女性与典型的女性在生存或繁殖方面有所不同，则性二态性的程度可能会降低或增强。 该项目旨在确定在一个特征（形态或行为）中表达的学位是否与其他特征中的雄孕的水平有关，这将表明控制性状表达的共同机制。 此外，该项目将努力确定在发育期间或成年期间的雄激素暴露是推动这种协变的，以及雌雄同体的女性是否因典型的雌性在生存或生殖成功中而有所不同。这些问题的答案将使我们对女性的社会行为，形态和激素暴露水平以及激素介导的复杂性状的发展之间的潜在联系。这项工作将与自由生活的鸣禽一起完成，并有助于培训本科生进行研究，作为培训计划的一部分，例如NSF的本科生研究经验（REU）和印第安纳大学的研究和奖学金（Stars）计划的学生成就。