Ecology can inform genetics: disassortative mating contributes to MHC polymorphism in Leach’s storm-petrels (Oceanodroma leucorhoa)

Studies of MHC-based mate choice in wild populations generally test hypotheses by assuming female choice and male-male competition, whether or not mate choice dynamics have been previously determined for the species under study. Here we examined mate choice patterns in a small burrow-nesting seabird, the Leach’s storm-petrel (Oceanodroma leucorhoa), using the Major Histocompatibility Complex (MHC). The life history and ecology of this species is extreme: both partners work together to fledge a single chick during the breeding season, a task that requires regularly traveling hundreds of kilometers to and from foraging grounds over a six to eight-week provisioning period. Using a five-year dataset unprecedented for this species (n=1027 adults and 925 chicks), we found a positive relationship between variation in female reproductive quality and heterozygosity at Ocle-DAB2, a MHC class IIB locus. Contrary to previous reports rejecting disassortative mating as a mechanism for maintaining gen...

野生种群中基于主要组织相容性复合体（Major Histocompatibility Complex, MHC）的配偶选择研究，通常会假设存在雌性选择和雄性间竞争来检验假说，无论研究物种的配偶选择动态是否已被预先确定。本研究利用MHC探究了一种小型穴居海鸟——白腰叉尾海燕（Leach’s storm-petrel, Oceanodroma leucorhoa）的配偶选择模式。该物种的生活史和生态特征极为特殊：繁殖季节中，雌雄双方共同协作抚育一只雏鸟直至其羽翼丰满；这项任务要求它们在6至8周的育雏期内，定期往返于觅食地，行程达数百公里。借助该物种前所未有的五年数据集（n=1027只成鸟，925只雏鸟），我们发现雌性繁殖质量的变异与Ocle-DAB2（一个MHC IIB类基因座）的杂合度呈正相关。与此前否定异配交配作为维持遗传...的机制的研究报告相反。