Data from: Genes and group membership predict gidgee skink (Egernia stokesii) reproductive pairs

Due to their role in mate choice, disease resistance and kin recognition, genes of the major histocompatibility complex (MHC) are good candidates for investigating genetic-based mate choice. MHC based mate choice is context dependent and influenced by many factors including social structure. Social structure diversity makes the Egernia group of lizards suitable for comparative studies of MHC based mate choice. We investigated mate choice in the gidgee skink (Egernia stokesii), a lizard that exhibits high levels of social group and spatial stability. Group membership was incorporated into tests of the good genes as heterozygosity and compatible genes hypotheses for adaptive (MHC) and neutral (microsatellite) genetic diversity (n = 47 individuals genotyped). Females were more likely to pair with a male with higher MHC diversity and with whom they had a lower degree of microsatellite relatedness. Males were more likely to pair with a female with higher microsatellite heterozygosity and with whom they shared a lower proportion of MHC alleles. Lizards were more likely to mate with an individual from within, rather than outside, their social group, which confirmed earlier findings for this species and indicated mate choice had already largely occurred prior to either social group formation or acceptance of an individual into an existing group. Thus, a combination of genes and group membership, rather than group membership alone, predicted mate choice in this species. This work will contribute to an enhanced understanding of squamate group formation and a deeper understanding of the evolution of sociality within all vertebrates.

主要组织相容性复合体（major histocompatibility complex, MHC）基因因其在配偶选择、疾病抗性以及亲缘识别中发挥的关键作用，成为探究基于遗传机制的配偶选择的理想研究对象。基于MHC的配偶选择具有情境依赖性，且受包括社会结构在内的多种因素影响。Egernia属蜥蜴类群具有多样的社会结构，因此适合开展基于MHC的配偶选择比较研究。本研究以吉吉石龙子（Egernia stokesii）为研究对象，该物种具有高度稳定的社会群体与空间分布结构。研究将群体归属纳入针对适应性（MHC）与中性（微卫星）遗传多样性的优质基因杂合性假说及相容基因假说的检验中，本次研究共对47个个体进行了基因分型。雌性个体更倾向于选择MHC多样性更高、且与自身微卫星亲缘度更低的雄性作为配偶。雄性个体则更倾向于选择微卫星杂合性更高、且与自身共享MHC等位基因比例更低的雌性作为配偶。该石龙子更倾向于与社会群体内部的个体交配，而非外部个体，这一结果验证了该物种的既往研究结论，同时表明配偶选择在社会群体形成或接纳新个体加入现存群体之前就已基本完成。因此，在该物种的配偶选择中，起预测作用的是遗传因素与群体归属的共同作用，而非仅依赖群体归属。本研究将有助于加深对有鳞目动物群体形成机制的理解，并推动对所有脊椎动物社会性演化的深入探究。