Data from: A quantitative review of MHC-based mating preference: the role of diversity and dissimilarity

A large body of literature is equivocal on causal processes through which selection operates on the Major Histocompatibility Complex genes (MHC). Besides their crucial immune functions, sexual selection hypotheses stipulate that MHC genes constitute a key molecular underpinning for mate choice in vertebrates. The last four decades saw growing empirical literature on the role of MHC diversity and dissimilarity in mate choice for a wide range of vertebrate animals, but with mixed support for its significance in natural populations. Using formal phylogenetic meta-analytic and meta-regression techniques, we quantitatively review the existing literature on MHC-dependent mating preferences in non-human vertebrates with a focus on the role of MHC diversity and dissimilarity. Overall, we found small, statistically non-significant, average effect sizes for both diversity- and dissimilarity-based mate choice (r = 0.113 and 0.064, respectively). However, meta-regression models revealed statistically significant support regarding female choice for diversity, and choice for dissimilarity (regardless of choosy sex) only when dissimilarity is characterised across multiple loci. Little difference was found among vertebrate taxa; however, the lack of statistical power meant statistically significant effects were limited to some taxa. We found little sign of publication bias, thus our results provide a fair representation of the current literature. In light of our quantitative assessment, interesting, yet underrepresented questions, methodological improvements, and fruitful future avenues of research are highlighted.

关于选择作用于主要组织相容性复合体基因（Major Histocompatibility Complex genes, MHC）的因果机制，现有大量研究文献尚未形成一致结论。除了发挥关键的免疫功能外，性选择假说指出，MHC基因是脊椎动物配偶选择的核心分子基础。过去四十年来，针对各类脊椎动物的MHC多样性与相异性在配偶选择中作用的实证研究不断涌现，但在自然种群中，该假说的有效性并未得到一致的支持证据。本研究采用规范的系统发育元分析与元回归技术，对当前非人类脊椎动物中依赖MHC的配偶偏好相关研究文献进行了定量综述，重点探讨MHC多样性与相异性的作用。总体而言，基于多样性和相异性的配偶选择的平均效应量均较小，且统计学上不显著（相关系数r分别为0.113与0.064）。然而，元回归模型显示，当相异性以多基因座特征进行表征时，雌性对MHC多样性的选择，以及无论选择者性别如何的相异性选择均得到了统计学上的显著支持。不同脊椎动物类群间的效应量差异较小，但由于统计效力有限，仅在部分类群中观察到了统计学显著的效应。本研究未发现明显的发表偏倚，因此研究结果能够较为公允地反映当前学界的研究现状。基于本次定量评估，本文还梳理了若干有趣但尚未得到充分关注的研究问题、方法论改进方向以及富有前景的未来研究路径。