The genetics of postmating isolation mechanisms between species of Drosophila

生殖在生物学中发挥着关键作用，了解基因变化如何阻碍杂交并允许不同物种的进化是进化中的一个中心问题。确定基因和表型之间的联系，例如那些限制个体群体之间基因流动的联系，对于理解物种形成过程和生物多样性的机制起源至关重要。在亲缘关系密切的物种中，生殖特征的差异往往比其他特征的差异更明显，这些差异影响物种杂交的潜力(即物种兼容性)。物种的亲和性不会随着交配过程本身而结束。事实上，在交配后很长一段时间内，男性与男性之间的竞争和女性的选择继续影响着亲和力。我的工作旨在了解生殖不亲和性的遗传基础，特别是导致杂交雄性不育的交配后合子异常和影响精子竞争的交配后合子挑战。在我下一阶段的研究中，我的目标是：1)测试先前识别的基因和基因类别(例如，蛋白酶)在杂交雄性不育(HMS)中的作用；2)确定导致物种间HMS的基因相互作用和途径；3)有助于我们理解导致物种间隔离的不亲和性的机制基础和表型表达；4)确定精子竞争和物种间后交配前合子隔离的共同遗传基础；5)了解雄性生殖基因的一般进化模式，特别是那些与交配后生殖隔离相关的基因，兴趣从编码转移到非编码的调控进化。在我的实验室里，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识别与生殖成功变异相关的候选基因。这一建议的创新之处在于将基因组水平上的这些方法与严格的表型描述和基因操作技术相结合，以识别导致杂交雄性不育和精子竞争力的特定基因。最终，结果将进一步加深我们对物种分化和这一过程背后的遗传基础的了解。测试基因表达变化在HMS中的作用将是创新和变革的，有助于我们理解基因调控和表型表现之间的联系。另一个创新方面将是确定导致HMS的基因相互作用和途径，而不是单个基因，并基于常见的遗传机制测试性别选择(精子竞争)是否可以导致或促进物种形成(交配前合子隔离)。

Reproduction plays a pivotal role in biology and understanding how gene changes can impede interbreeding and allow for the evolution of different species is a central problem in evolution. Identifying links between genes and phenotypes, such as those that restrict gene flow between groups of individuals, is critical for understanding the process of speciation and the mechanistic origin of biodiversity. Among closely related species, differences in reproductive traits tend to be more pronounced than differences in other traits, and these differences affect the potential of species to interbreed (i.e. species compatibility). Species compatibility does not end with the mating process itself. Indeed male-male competition and female choice continue to influence compatibility long after mating. My work aims to understand the genetic basis of reproductive incompatibilities, specifically postmating postzygotic anomalies that render hybrid males sterile and postcopulatory prezygotic challenges that affect sperm competition. During the next phase of my research I aim to: 1) Test the role of previously identified genes and gene classes (e.g. proteases) in hybrid male sterility (HMS), 2) identify gene interactions and pathways contributing to HMS between species, 3) contribute towards our understanding of the mechanistic basis and phenotypic expression of incompatibilities that cause isolation between species, 4) identify common genetic basis to sperm competition and postmating prezygotic isolation between species, and 5) understand patterns of evolution of male reproductive genes in general and those linked to postmating reproductive isolation in particular, with an interest moving from coding to noncoding regulatory evolution. 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. The innovation of this proposal is to combine these approaches at the genome level, with rigorous phenotypic descriptions and gene manipulation technologies to identify specific genes contributing to hybrid male sterility and sperm competitiveness. Ultimately, results will further our knowledge on species differentiation and the genetic basis underlying such process. Testing the role of changes in gene expression in HMS will be innovative and transformative towards our understanding of links between gene regulation and phenotypic manifestation. Another innovative aspect will be identifying gene interactions and pathways rather than single genes contributing to HMS and testing whether, based on common genetic mechanisms, sexual selection (sperm competition) can cause or contribute to speciation (postmating prezygotic isolation).