Poissant J, Morrissey M B, Gosler A G, Slate J, Sheldon B C
Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn, UK.
Department of Animal and Plant Sciences, University of Sheffield, Sheffield, UK.
J Evol Biol. 2016 Oct;29(10):2022-2035. doi: 10.1111/jeb.12925. Epub 2016 Jul 14.
When selection differs between the sexes for traits that are genetically correlated between the sexes, there is potential for the effect of selection in one sex to be altered by indirect selection in the other sex, a situation commonly referred to as intralocus sexual conflict (ISC). While potentially common, ISC has rarely been studied in wild populations. Here, we studied ISC over a set of morphological traits (wing length, tarsus length, bill depth and bill length) in a wild population of great tits (Parus major) from Wytham Woods, UK. Specifically, we quantified the microevolutionary impacts of ISC by combining intra- and intersex additive genetic (co)variances and sex-specific selection estimates in a multivariate framework. Large genetic correlations between homologous male and female traits combined with evidence for sex-specific multivariate survival selection suggested that ISC could play an appreciable role in the evolution of this population. Together, multivariate sex-specific selection and additive genetic (co)variance for the traits considered accounted for additive genetic variance in fitness that was uncorrelated between the sexes (cross-sex genetic correlation = -0.003, 95% CI = -0.83, 0.83). Gender load, defined as the reduction in a population's rate of adaptation due to sex-specific effects, was estimated at 50% (95% CI = 13%, 86%). This study provides novel insights into the evolution of sexual dimorphism in wild populations and illustrates how quantitative genetics and selection analyses can be combined in a multivariate framework to quantify the microevolutionary impacts of ISC.
当两性之间在具有遗传相关性的性状上的选择存在差异时，一个性别的选择效应有可能因另一个性别的间接选择而改变，这种情况通常被称为基因座内性冲突（ISC）。虽然ISC可能很常见，但在野生种群中很少被研究。在这里，我们对英国怀瑟姆森林中的大山雀（Parus major）野生种群的一组形态性状（翅长、跗跖长、喙深和喙长）进行了ISC研究。具体来说，我们通过在多变量框架中结合性别内和性别间的加性遗传（协）方差以及性别特异性选择估计，量化了ISC的微进化影响。同源的雄性和雌性性状之间存在较大的遗传相关性，同时有性别特异性多变量生存选择的证据表明，ISC可能在该种群的进化中发挥显著作用。综合考虑，所研究性状的多变量性别特异性选择和加性遗传（协）方差解释了两性之间不相关的适合度加性遗传方差（跨性别遗传相关性 = -0.003，95%置信区间 = -0.83，0.83）。性别负荷定义为由于性别特异性效应导致种群适应率的降低，估计为50%（95%置信区间 = 13%，86%）。这项研究为野生种群中两性异形的进化提供了新的见解，并说明了如何在多变量框架中结合数量遗传学和选择分析来量化ISC的微进化影响。
