X-Chromosome Control of Genome-Scale Recombination Rates in House Mice.
X-Chromosome Control of Genome-Scale Recombination Rates in House Mice.
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DOI：
10.1534/genetics.116.197533
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发表时间：
2017-04
期刊：
影响因子：
3.3
通讯作者：
Dumont BL
中科院分区：
文献类型：
--
作者：
Dumont BL
重组中的性别差异在哺乳动物中很普遍，但这种模式的原因却鲜为人知。此前，来自两个相互干扰的家鼠亚种--肌肉小鼠和卡氏小鼠的雄性被证明在它们的全局交换频率上表现出∼30%的差异。这种交叉率差异在很大程度上是由X染色体上的六个常染色体基因座和一个大效应基因座解释的。有趣的是，这个X连锁基因座上的等位基因效应是超越性的，导致交叉率增加的等位基因是由低交叉率的M.Castaneus亲本传递的。尽管雄性之间存在明显的差异，但这些亚种的雌性之间表现出相似的交叉率，这引发了这样一个问题：这种性别的重组是如何受到基因控制的。在这里，我分析了可公开获得的合作杂交早期世代的基因数据，这是一个由重组近交系菌株组成的八方小组，以估计具有不同亚种来源的性染色体基因型的雌性小鼠的交叉频率。与X染色体在男性中的超常影响一致，我发现遗传了卡氏支原体X染色体的雌性比没有X染色体的雌性具有更高的平均交叉率。X染色体在男性和女性中的差异遗传为这一性状的性别受限进化提供了一个简单的遗传解释。此外，具有拮抗作用的X连锁和常染色体交叉率修饰物的存在暗示了一种潜在的遗传冲突，这是由于在雄性和雌性中选择了不同的交叉率最优。
Sex differences in recombination are widespread in mammals, but the causes of this pattern are poorly understood. Previously, males from two interfertile subspecies of house mice, Mus musculus musculus and M. m. castaneus, were shown to exhibit a ∼30% difference in their global crossover frequencies. Much of this crossover rate divergence is explained by six autosomal loci and a large-effect locus on the X chromosome. Intriguingly, the allelic effects at this X-linked locus are transgressive, with the allele conferring increased crossover rate being transmitted by the low crossover rate M. m. castaneus parent. Despite the pronounced divergence between males, females from these subspecies exhibit similar crossover rates, raising the question of how recombination is genetically controlled in this sex. Here, I analyze publicly available genotype data from early generations of the Collaborative Cross, an eight-way panel of recombinant inbred strains, to estimate crossover frequencies in female mice with sex-chromosome genotypes of diverse subspecific origins. Consistent with the transgressive influence of the X chromosome in males, I show that females inheriting an M. m. castaneus X possess higher average crossover rates than females lacking the M. m. castaneus X chromosome. The differential inheritance of the X chromosome in males and females provides a simple genetic explanation for sex-limited evolution of this trait. Further, the presence of X-linked and autosomal crossover rate modifiers with antagonistic effects hints at an underlying genetic conflict fueled by selection for distinct crossover rate optima in males and females.