The contribution of the mitochondrial genome to sex-specific fitness variance

Maternal inheritance of mitochondrial DNA (mtDNA) facilitates the evolutionary accumulation of mutations with sex-biased fitness effects. Whereas maternal inheritance closely aligns mtDNA evolution with natural selection in females, it makes it indifferent to evolutionary changes that exclusively benefit males. The constrained response of mtDNA to selection in males can lead to asymmetries in the relative contributions of mitochondrial genes to female versus male fitness variation. Here, we examine the impact of genetic drift and the distribution of fitness effects (DFE) among mutations – including the correlation of mutant fitness effects between the sexes – on mitochondrial genetic variation for fitness. We show how drift, genetic correlations, and skewness of the DFE determine the relative contributions of mitochondrial genes to male versus female fitness variance. When mutant fitness effects are weakly correlated between the sexes, and the effective population size is large, mitocho...

线粒体DNA（mtDNA）的母系遗传，可促进携带性别偏倚适合度效应的突变在演化过程中积累。母系遗传虽能使mtDNA的演化与雌性的自然选择紧密契合，却会令其对仅对雄性有益的演化改变无动于衷。线粒体DNA对雄性选择的受限响应，可能导致线粒体基因在雌性与雄性适合度变异的相对贡献上出现不对称性。本研究探讨了遗传漂变以及突变间的适合度效应分布（DFE）——包括不同性别间突变适合度效应的相关性——对线粒体基因适合度遗传变异的影响。我们阐明了遗传漂变、遗传相关以及适合度效应分布的偏态，如何决定线粒体基因对雄性与雌性适合度变异的相对贡献。当不同性别间的突变适合度效应相关性较弱、且有效种群规模较大时，线粒体……