Evolution of Drosophila genes with sex-biased expression

从果蝇和其他分类群的基因组研究中出现的一个常见模式是，与雌性和非性别偏见基因相比，雄性偏见基因(即主要或仅在雄性身上表达的基因)进化得更快。这种模式被认为是积极(或性)选择导致的男性偏向基因适应性进化增加的结果。然而，这也可以用放松的选择性约束来解释。为了区分这些可能性和识别最近经历了适应性进化的基因，我们提出了几种群体遗传学和功能基因组分析，包括：(1)比较非同义/同义多态和性别偏见基因的差异性，(2)比较X连锁和常染色体性别偏见基因的进化模式，(3)进行微阵列实验以识别除特征良好的黑腹果蝇以外的果蝇物种中的性别偏见基因，(4)对推测的适应性进化的雄性偏见基因进行功能分析，以及(5)高度分化的物种鹅绒草中性别偏见基因的群体遗传学分析。

A common pattern that has emerged from genomic studies of Drosophila and other taxa is that male-biased genes (i.e., genes expressed predominantly or exclusively in males) evolve rapidly in comparison to female- and nonsex-biased genes. This pattern is thought to be a result of increased adaptive evolution in malebiased genes due to positive (or sexual) selection. However, it could also be explained by relaxed selective constraint. To distinguish between these possibilities and identify genes that have undergone recent adaptive evolution, we propose several population genetic and functional genomic analyses, including: (1) comparing rates of nonsynonymous/synonymous polymorphism and divergence in sex-biased genes, (2) comparing evolutionary patterns of X-linked vs. autosomal sex-biased genes, (3) performing microarray experiments to identify sex-biased genes in Drosophila species other than the well-characterized D. melanogaster, (4) functional analysis of putative adaptively-evolving male-biased genes, and (5) population genetic analysis of sex-biased genes in the highly-subdivided species, D. ananassae.