Evolutionary genetics of male quality and competitive reproductive success

自然界中的一个物种，很可能雌性会使用多个雄性的精子，从而产生多个后代。这种精子竞争产生了强烈的选择，推动了雄性和雌性生殖特征的快速进化，并可能有助于维持物种边界。尽管精子竞争在进化上具有重要意义，但在其自然环境——雌性生殖道——中研究精子竞争一直很困难，因为来自不同雄性的精子通常难以区分，而雌性生殖道通常不适合显微镜观察。这项拟议中的研究利用了果蝇的实验和遗传易变性，产生了200个遗传分化的种群，这些种群的精子头部表达绿色或红色荧光标记。因此，该研究将调查精子的变异如何影响精子的竞争成功，精子性状如何在遗传上变化和共变，并询问女性的基因组如何影响她儿子的精子性状。该研究还将量化male×male×female基因相互作用，并研究饲养环境如何影响精子特征。这项拟议的研究将极大地促进对精子性状的复杂遗传学和生殖成功变异背后的精子-雌性相互作用的理解。不明原因的人类不孕症诊断可能是伴侣之间相互作用的结果，但区分不相容的潜在来源需要详细了解生殖过程和生殖成功的遗传学。此外，这项研究产生的荧光精子种群在世界各地的实验室研究遗传学、发育和受精以及教育公众有关生殖生物学方面证明是有价值的。

Name a species in nature, and chances are, its females use sperm from more than one male, resulting in multiple paternity of offspring. This sperm competition generates strong selection that drives rapid evolution of both male and female reproductive traits and may contribute to the maintenance of species boundaries. Despite its evolutionary importance, sperm competition has been difficult to study within its natural environment, the female reproductive tract, because sperm from different males are generally indistinguishable, and the female reproductive tract is often poorly suited for microscopy. The proposed research exploits the experimental and genetic tractability of the fruit fly, Drosophila melanogaster, to generate 200 genetically differentiated populations whose sperm heads express a green or red fluorescent marker. Thus, the research will investigate how sperm variation contributes to sperm competitive success, how sperm traits genetically vary and covary, and ask how the female's genome contributes to her sons' sperm traits. The research will also quantify male×male×female genetic interactions and examine how rearing environment impacts sperm traits.The proposed research will greatly advance understanding of the complex genetics of sperm traits and of sperm-female interactions underlying variation in reproductive success. Human infertility diagnoses of unknown cause may be a consequence of interactions between partners, but distinguishing potential sources of incompatibility necessitates a detailed understanding of reproductive processes and the genetics of reproductive success. Also, fluorescent-sperm populations generated for this research are proving valuable in laboratories worldwide studying genetics, development and fertilization and in educating the public about reproductive biology.