The genetic and mechanistic basis of female preference: a key trait initiating the speciation process

项目摘要 复杂性状的遗传基础，尤其是行为性状，往往很难剖析 因为基因的影响往往取决于它们发生的遗传背景。 此外，基因通常涉及多种表型（它们是多效性的） 使他们在哪里/何时表达的背景对于理解他们的 对表型的影响。物种形成提供了一个研究复杂性状的机会， 当新的谱系分化时，雌性行为会受到强烈的选择， 拒绝“错误”血统的雄性。这种强选择导致遗传变化， 可以识别，然后可以剖析这些变化的影响。一种这样的情况 发生在果蝇的“种族”中。有很强的生殖隔离 来自祖先范围（南部非洲）和世界性的人群之间 人口。来自祖先领地的雌性会排斥来自世界各地的雄性。一个候选 这种行为的基因desat 2已经被鉴定出来。非洲人D.黑腹区 多效性;它们赋予女性偏好，并导致女性 信息素（表皮碳氢化合物）。目前还不清楚女性的性别差异 偏好是由desat 2控制的，哪些机制影响女性的行为。我会 研究desat 2如何影响女性交配行为，首先检查遗传如何 背景与不同的desat 2等位基因相互作用以影响雌性行为。我来设计 所有菌株都具有共同的desat 2等位基因，但遗传背景不同。这将 让我来确定遗传背景如何改变desat 2对女性的影响。 行为（目标1）。然后，我将看看desat 2对女性特定信息素的影响 （表皮碳氢化合物）和desat 2的表达模式。来看待女性的角色 角质层碳氢化合物我将设计表达desat 2但不产生雌性的果蝇 表皮碳氢化合物然后我就能把精确量的表皮碳氢化合物 问其故，以其故。最后，我将分析组织特异性 使用定量PCR和高分辨率技术检测desat 2在神经元组织中的表达 显微镜在特定神经元组织中的表达表明desat 2有助于 女性对社区卫生服务的感知（Aim 3）。 这项研究的结果将提供深入了解如何多效性性状和遗传 背景有助于复杂的行为表型。

Project Summary The genetic basis of complex traits, especially behavioral traits, is often difficult to dissect because the effects of genes often depend on the genetic background in which they occur. Additionally, genes are typically involved in multiple phenotypes (they are pleiotropic) making the context of where/when they are expressed important to understanding their impacts on phenotype. Speciation offers an opportunity to study complex traits because when new lineages diverge there is strong selection for female behavior so that females reject males of the “wrong” lineage. This strong selection results in genetic changes that can be identified and then the impacts of these changes can be dissected. One such case occurs in “races” of Drosophila melanogaster. There is strong reproductive isolation between populations that are from the ancestral range (Southern Africa) and cosmopolitan populations. Females from the ancestral range reject cosmopolitan males. One candidate gene for this behavior, desat2, has been identified. Alleles of African D. melanogaster are pleiotropic; they confer female preference and contribute to differences in female pheromones (cuticular hydrocarbons). It remains unknown how much variation in female preference is controlled by desat2, and which mechanisms affect female behavior. I will study how desat2 influences female mating behavior by first examining how genetic background interacts with different desat2 alleles to affect female behavior. I will engineer strains that all share a common desat2 allele but differ in their genetic background. This will allow me to determine how genetic background alters the impact of desat2 on female behavior (Aim1). I will then look at the effects of desat2 on female specific pheromones (cuticular hydrocarbons) and expression patterns of desat2. To look at the role of female cuticular hydrocarbons I will engineer flies that express desat2 but do not produce female cuticular hydrocarbons. I can then add precise amounts of cuticular hydrocarbons back to the flies and ask how they affect behavior (Aim2). Lastly, I will assay tissue specific expression of desat2 in neuronal tissue using quantitative PCR and high-resolution microscopy. Expression in specific neuronal tissue will suggest that desat2 contributes to female perception of CHCs (Aim3). The outcomes of this research will provide insight into how pleiotropic traits and genetic background contribute to complex behavioral phenotypes.