Data from: Genomic analysis of MHC-based mate choice in the monogamous California mouse

Variation at Major Histocompatibility Complex (MHC) genes is thought to be an important mechanism underlying mate choice in vertebrates, with individuals typically predicted to prefer MHC-dissimilar reproductive partners. However, analyses based on individual MHC loci have generated contradictory results regarding the role of these genes in mate choice decisions. To provide a more comprehensive assessment of relationships between MHC variation and mating behavior, we used an exome capture strategy to characterize variability at 13 MHC loci, 312 innate immune system genes, and 1,044 non-immune genes in 25 obligate monogamous pairs of California mice (Peromyscus californicus) from two free-living populations of this species in Monterey County, California. Pairwise genotypic comparisons and analyses of SNP-based allelic differences failed to detect disassortative mating based on MHC variability; reproductive partners were not more dissimilar than randomly generated male-female pairs at MHC, innate or non-immune loci. Within populations, individuals tended to be more closely related at MHC genes than at innate or non-immune genes. Consistent with the functional role of immunogenes, the two study populations were highly differentiated at MHC and innate genes but not at non-immune loci. Collectively, our results suggest that MHC genetic variation in California mice reflects local differences in pathogen exposure rather than disassortative mating based on variability at MHC Class I and II genes.主要组织相容性复合体（Major Histocompatibility Complex，MHC）基因的变异被认为是脊椎动物配偶选择的重要潜在机制，学界普遍认为个体更偏好选择与自身MHC型别相异的繁殖伴侣。然而，针对单个MHC基因座的相关研究，在这类基因在配偶选择决策中所发挥的作用方面，得出了相互矛盾的结论。为更全面地评估MHC变异与交配行为之间的关联，本研究采用外显子组捕获策略，对来自加利福尼亚州蒙特雷县两个野生种群的25对专性一夫一妻制加利福尼亚鹿鼠（Peromyscus californicus）的13个MHC基因座、312个先天免疫系统基因以及1044个非免疫基因的变异特征进行了表征。通过成对基因型比较以及基于单核苷酸多态性（Single Nucleotide Polymorphism，SNP）的等位基因差异分析，本研究未能检测到基于MHC变异的负选型交配现象；繁殖伴侣在MHC、先天免疫或非免疫基因座上的遗传差异程度，并未高于随机生成的雌雄配对个体。在种群内部，个体在MHC基因上的亲缘关系往往比在先天免疫或非免疫基因上更为紧密。与免疫基因的功能特性相一致，两个研究种群在MHC和先天免疫基因上呈现出高度遗传分化，但在非免疫基因座上则无此类分化特征。综上，本研究结果表明，加利福尼亚鹿鼠的MHC遗传变异反映的是病原体暴露的本地种群差异，而非基于MHC I类和II类基因变异的负选型交配。