The Genetics and Genomics of Sex-Ratio Meiotic Drive in Drosophila Affinis

性别比例减数分裂驱动存在于包括节肢动物、哺乳动物和植物在内的多种后生动物群体中。驱动力的产生是因为自私的性染色体，通常是X染色体，能够削弱异性染色体。结果是携带驱动X染色体的雄性几乎所有的后代都是雌性。理解性别比减数分裂驱动的遗传学一直受到驱动位点与大反转的关联的阻碍。亲缘果蝇的性别比例系统有一个额外的复杂水平：缺乏Y染色体的雄性是有生育能力的。事实上，一个有驱动X染色体而没有Y染色体的男性生出的大部分是儿子——在没有Y染色体的情况下，驱动X似乎有自杀倾向。我提出了一种使用下一代测序对亲缘果蝇性别比例减数分裂驱动进行基因组分析的策略。通过对男性睾丸中驱动和非驱动X染色体的比较基因组学和两条染色体的转录组学分析，我希望确定参与驱动表型的候选基因。随后的分析将有助于识别特定的基因。这种方法是新颖的，因为我将尝试在非模式物种的倒置中绘制基因，并且我开发的方法将促进其他系统中的类似分析。从我们的分析中获得的生物学见解可能会揭示性别比例减数分裂驱动和性染色体进化的遗传学，这两者都对生育有影响。

Sex-ratio meiotic drive is found in diverse groups of metazoans including arthropods, mammals and plants. Drive occurs because a selfish sex chromosome, usually the X chromosome, is able to debilitate the opposite sex chromosome. The result is that males carrying the driving X chromosome produce almost all daughters. Understanding the genetics of sex-ratio meiotic drive has been hindered by the association of drive loci with large inversions. The Drosophila affinis sex-ratio system has an additional level o complexity: males lacking a Y chromosome are fertile. In fact, a male with a driving X chromosome and no Y produces mostly sons - the driving X appears to be suicidal in the absence of a Y chromosome. I propose a strategy using next generation sequencing for genomic analysis of sex-ratio meiotic drive in Drosophila affinis. Using a combination of comparative genomics of the driving and non-driving X chromosomes and transcriptomic analysis of both chromosomes in males testes, I hope to identify candidate genes involved in the drive phenotype. Subsequent analysis will help identify specific genes. The approach is novel in that I will be attempting to map genes within inversions in a non-model species, and the methods I develop will facilitate similar analysis in other systems. The biological insight obtaine from our analysis may shed light on the genetics of sex-ratio meiotic drive and sex chromosome evolution, both of which have implications for fertility.