Sexual selection and molecular evolution of postmating reproductive incompatibilities

生殖在进化生物学中具有核心作用，因为生殖活动的中断，从交配到配子竞争受精的能力，都会降低适应性。在相关物种中，繁殖性状的差异比其他性状的差异更明显，这种差异可以影响物种的相容性并有助于物种形成。我的工作集中在两个现象，影响交配后生殖成功;同种精子优先（CSP）和配子发育中断不育杂交。我也有兴趣了解性选择对与交配后成功相关的基因的作用。在我的研究的下一阶段，我的目标是：1）鉴定和功能性测试候选CSP基因，2）辨别性选择和由其他因素驱动的快速分化，例如CSP验证基因和与交配后生殖适合度相关的其他基因的宽松选择约束或突变偏差，3）探讨调控序列的遗传分化在种间雄性杂交后代精子发生基因下调中的作用。在我的实验室中，我们成功地结合了经典遗传学、基因组学和分子进化方法来鉴定与生殖成功变异相关的候选基因，特别是参与CSP的基因和影响精子发生的基因变异。在这项研究中，我通过使用SNP-表型关联和遗传敲除测试这些候选基因的功能意义来扩展这项研究，从而为基因验证提供明确的证据。与繁殖成功和受精有关的基因将被用来测试性选择如何塑造它们的进化。这些结果将有助于我们在分子水平上了解物种分化和生殖基因进化过程中性选择的影响。已确定的基因将成为比较基因组搜索的直接目标，并确定与进化转型有关的保守性和趋异性。

Reproduction has a central role in evolutionary biology because disruptions in reproductive activities, from mating to gamete ability to compete for fertilization, reduce fitness. Among related species, differences in reproductive traits are more pronounced than differences in other traits and such differences can affect species compatibility and contribute to speciation. My work focuses on two phenomena that influence reproductive success after copulation; conspecific sperm precedence (CSP) and gamete development disruption in sterile hybrids. I am also interested in understanding the role of sexual selection on genes linked to postcopulatory success. During the next phase of my research I aim to: 1) identify and functionally test candidate CSP genes, 2) discern between sexual selection and rapid divergence driven by other factors, such as relaxed selective constraints or mutational bias at CSP validated genes and other genes linked to postcopulatory reproductive fitness, 3) evaluate the role of genetic divergence in regulatory sequences in the down regulation of spermatogenesis genes in interspecies male hybrids. In my lab, we have successfully used a combination of classical genetics, genomics and molecular evolution approaches to identify candidate genes associated with variation in reproductive success, particularly genes involved in CSP and gene variants affecting spermatogenesis. In this grant, I expand upon this research by testing the functional significance of these candidate genes using SNP-phenotype associations and genetic knockdowns, thus providing definitive evidence for gene validation. Genes linked to reproductive success and fertilization will be used to test how sexual selection molded their evolution. These results will contribute to our knowledge of species differentiation and the impact of sexual selection at the molecular level during the evolution of reproductive genes. Identified genes will become immediate targets for comparative genomic searches and the identification of conservation and divergence linked to evolutionary transitions.