Data from: Dissecting the genetic architecture of F1 hybrid sterility in house mice

Hybrid sterility as a postzygotic reproductive isolation mechanism has been studied for over 80 years, yet the first identifications of hybrid sterility genes in Drosophila and mouse are quite recent. To study the genetic architecture of F_1 hybrid sterility between young subspecies of house mouse Mus m. domesticus and Mus m. musculus we conducted QTL analysis of a backcross between inbred strains representing these two subspecies and probed the role of individual chromosomes in hybrid sterility using the inter-subspecific chromosome substitution strains. We provide direct evidence that the asymmetry in male infertility between reciprocal crosses is conferred by the middle region of Mus m. musculus Chr X, thus excluding other potential candidates such as Y, imprinted genes, and mitochondrial DNA. QTL analysis identified strong hybrid sterility loci on Chr 17 and Chr X and predicted a set of interchangeable autosomal loci, a subset of which is sufficient to activate the Dobzhansky-Muller incompatibility of the strong loci. Overall, our results indicate the oligogenic nature of F_1 hybrid sterility, which should be amenable to reconstruction by proper combination of chromosome substitution strains. Such prefabricated model system should help to uncover the gene networks and molecular mechanisms underlying hybrid sterility.杂种不育作为一种合子后生殖隔离机制，已被研究逾80年，然而在果蝇与小鼠中首次鉴定出杂种不育基因的时间却相当晚近。为研究小家鼠（Mus m. domesticus）与小家鼠（Mus m. musculus）两个年轻亚种间F₁杂种不育的遗传架构，我们对代表这两个亚种的近交系回交群体开展了数量性状基因座（Quantitative Trait Locus, QTL）分析，并借助亚种间染色体替换系探究了单个染色体在杂种不育中的作用。我们提供了直接证据，证明正反交间雄性不育的不对称性由小家鼠（Mus m. musculus）X染色体（Chromosome X, Chr X）的中部区域决定，由此排除了Y染色体、印记基因以及线粒体DNA等其他潜在候选因素。QTL分析在17号染色体与X染色体上鉴定出了强效杂种不育位点，并预测了一组可互换的常染色体位点，其中的一个子集足以激活强效位点的多布赞斯基-穆勒不相容性。总体而言，我们的研究结果表明F₁杂种不育具有寡基因遗传本质，该特性可通过合理组合染色体替换系实现重建。此类预制化模型体系将有助于解析杂种不育背后的基因调控网络与分子机制。