Department of Animal Behavior, Bielefeld University, Bielefeld, Germany.
Mol Ecol. 2021 Dec;30(24):6513-6516. doi: 10.1111/mec.16255. Epub 2021 Nov 9.
Immune defence is a key component of fitness, and individuals are expected to have evolved preferences for mates that ensure immunocompetent offspring. Potential preferences include those for mates with specific heritable immune gene profiles ("good genes") or for immunogenetically dissimilar mates to increase offspring immune gene diversity. The major histocompatibility complex (MHC) is by far the most investigated immune gene in mate choice studies, but we still know very little about its role in sexual selection for genetic benefits. In this issue of Molecular Ecology, Huang et al. capitalize on the extraordinary wealth of behavioural, life history and genetic/genomic data from the free-living Soay sheep population on the Island of Hirta to address this problem. While the authors find evidence of both pre- and postcopulatory MHC-based sexual selection, postcopulatory MHC-dissimilar mate choice is indistinguishable from genome-wide effects, suggesting it is a byproduct of inbreeding avoidance in Soay sheep. The study's comprehensive sampling ensures that inferences are generalizable to the entire population and provides a gold standard for studies investigating immune gene-based sexual selection.
免疫防御是适应度的一个关键组成部分，人们期望进化出对能确保免疫能力后代的配偶的偏好。潜在的偏好包括那些具有特定可遗传免疫基因特征（“好基因”）的配偶，或者具有免疫遗传上不同的配偶，以增加后代的免疫基因多样性。主要组织相容性复合体（MHC）是迄今为止在配偶选择研究中研究最多的免疫基因，但我们对其在遗传利益的性选择中的作用仍然知之甚少。在本期《分子生态学》中，Huang 等人利用 Hirta 岛上自由生活的 Soay 绵羊群体的非凡丰富的行为、生活史和遗传/基因组数据，来解决这个问题。虽然作者发现了基于 MHC 的预交配和交配后性选择的证据，但交配后 MHC 不同的配偶选择与全基因组效应无法区分，这表明它是 Soay 绵羊避免近亲繁殖的副产品。该研究的全面抽样确保了推断可以推广到整个种群，并为研究基于免疫基因的性选择提供了黄金标准。
