DISSERTATION RESEARCH: Individual variation and male-female dimorphism: the role of testosterone and gene expression

雄性和雌性的基因组几乎相同，但雄性和雌性在外表、生理和行为上可能会有很大的不同。性别表型差异的直接解释是基因表达的差异，即哪些基因是开启的，还是关闭的？在男性和女性身上。但性别究竟如何影响基因表达仍是一个悬而未决的问题，仍有许多有待研究。睾丸激素等激素可能是控制男性和女性基因表达差异的候选激素。到目前为止，这一领域的大部分研究都集中在荷尔蒙的实验操作上，而不是循环荷尔蒙水平的自然个体差异所起的作用。该奖项支持的研究提出了两个主要问题：(1)哪些基因和基因网络受到睾酮表型自然的个体差异的影响，以及(2)男性和女性在受影响的基因和基因网络方面有何不同？黑眼鸣鸟(Junco Hyemalis)是一种北美鸣鸟，它将成为研究的对象，因为这个系统中的基因组工具最近的发展，以及关于它的自然历史、对睾丸激素的反应和行为性别差异的丰富历史数据；所有这些都是在野生种群中进行的研究。这个项目的目标的成功完成将加强我们对与睾丸激素自然变异相关的基因和基因网络的理解。这里提出的研究将产生更广泛的影响，因为它将为本科生研究提供独特的机会：这项研究的初步阶段已经为来自代表性不足群体的四个人提供了本科生研究机会。

Males and females have nearly identical genomes, yet males and females can differ dramatically in appearance, physiology, and behavior. The proximate explanation for sex differences in phenotype is differences in gene expression, i.e., which genes are ?turned on or off? in males and females. But exactly how gender affects gene expression is an open question where much remains to be learned. Hormones such as testosterone are likely candidates for controlling differences in gene expression of genes in males and females. To date much of the research in this area has focused on experimental manipulation of hormones, rather than on the role of natural, individual variation in levels of circulating hormone. The research supported by this award asks two primary questions: (1) what genes and gene networks are affected by natural, individual variation in testosterone phenotype, and (2) how do males and females differ in affected genes and gene networks? The dark-eyed junco (Junco hyemalis), a North-American songbird, will be the subject of study because of the recent development of genomic tools in this system and the wealth of historical data on its natural history, response to testosterone, and sex differences in behavior; all studied in a wild population. Successful completion of the aims of this project will enhance our understanding of the genes and gene networks that are related to natural variation in testosterone. The research proposed here will have broader impacts because it will provide unique opportunities for undergraduate research: the preliminary stages of this research have already led to undergraduate research opportunities for four individuals from underrepresented groups.