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

项目摘要 复杂特征的遗传基础，特别是行为特征，通常很难剖析。 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)。 在何处/何时表达它们的上下文对于理解它们的 对表型的影响。物种形成为研究复杂性状提供了机会，因为 当新的世系分化时，对雌性行为有很强的选择，因此雌性 拒绝“错误”血统的男性。这种强烈的选择导致了基因变化， 可以被识别，然后可以剖析这些变化的影响。一起这样的案件 出现在果蝇的“种族”中。有很强的生殖隔离 来自祖先山脉(南部非洲)和世界各地的种群之间 人口。来自祖先的雌性拒绝来自世界各地的雄性。一位候选人 这种行为的基因desat2已经被确定。非洲黑腹果蝇的等位基因有 多效性；它们赋予女性偏好，并促成女性的差异 信息素(角质层碳氢化合物)目前尚不清楚女性的变异程度有多大 偏好由desat2控制，以及哪些机制影响女性的行为。这就做 研究desat2如何影响雌性交配行为，首先研究遗传 背景与不同的desat2等位基因相互作用，影响女性的行为。我会当工程师 所有菌株都有共同的desat2等位基因，但它们的遗传背景不同。这将是 请允许我确定遗传背景如何改变desat2对女性的影响 行为(Aim1)。然后我将研究desat2对雌性特定信息素的影响。 (角质层碳氢化合物)和desat2的表达模式。审视女性的角色 角质层碳氢化合物我会设计出表达desat2但不产生雌性的苍蝇 角质层碳氢化合物。然后我可以将精确数量的角质层碳氢化合物添加回 并询问它们如何影响行为(AIM2)。最后，我将化验组织特异性 应用定量聚合酶链式反应和高分辨技术检测神经元组织中desat2的表达 显微镜。在特定神经元组织中的表达将表明desat2参与了 女性对社区卫生服务的认知(Aim3)。 这项研究的结果将为多效性特征和遗传 背景与复杂的行为表型有关。

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.