Data from: Mitochondrial genetic effects on reproductive success: signatures of positive intrasexual, but negative intersexual pleiotropy

Theory predicts that maternal inheritance of mitochondria will facilitate the accumulation of mtDNA mutations that are male biased, or even sexually antagonistic, in effect. While there are many reported cases of mtDNA mutations conferring cytoplasmic male sterility in plants, historically it was assumed such mutations would not persist in the streamlined mitochondrial genomes of bilaterian metazoans. Intriguingly, recent cases of mitochondrial variants exerting male-biases in effect have come to light in bilaterians. These cases aside, it remains unknown whether the mitochondrial genetic variation affecting phenotypic expression, and in particular reproductive performance, in bilaterians is routinely comprised of sex-biased or sex-specific variation. If selection consistently favours mtDNA variants that augment female fitness, but at cost to males, this could shape patterns of pleiotropy and lead to negative intersexual correlations across mtDNA haplotypes. Here, we show that genetic variation across naturally occurring mitochondrial haplotypes affects components of reproductive success in both sexes, in the fruit fly Drosophila melanogaster. We find that intrasexual correlations across mitochondrial haplotypes, for components of reproductive success, are generally positive, while intersexual correlations are negative. These results accord with theoretical predictions, suggesting that maternal inheritance has led to the fixation of numerous mutations of sexually antagonistic effect.

理论预测，线粒体的母系遗传将促进偏向雄性（甚至具有性拮抗效应）的线粒体DNA（mitochondrial DNA，mtDNA）突变积累。尽管已有大量关于植物中线粒体DNA突变引发细胞质雄性不育的报道，但长期以来学界普遍认为，这类突变无法在两侧对称后生动物的精简线粒体基因组中存续。
值得注意的是，近期在两侧对称动物中陆续发现了线粒体变异体产生雄性偏向效应的案例。然而除这些个案之外，目前仍不清楚：在两侧对称动物体内，影响表型表达（尤其是繁殖性能）的线粒体遗传变异，是否普遍存在性别偏向或性别特异性变异。
若选择压力持续青睐能够提升雌性适合度却以牺牲雄性适合度为代价的线粒体变异体，这将塑造多效性模式，并导致跨线粒体DNA单倍型的两性间出现负相关。
本研究以黑腹果蝇（*Drosophila melanogaster*）为研究对象，证实天然存在的线粒体DNA单倍型间的遗传变异，会同时影响两性的繁殖成功相关性状。
我们发现，针对繁殖成功相关组分，不同线粒体单倍型间的同性相关性普遍为正，而跨性别的相关性则为负。
上述结果与理论预测相符，表明线粒体的母系遗传已促使诸多具有性拮抗效应的突变得以固定。