Evolution & Ecology Research Centre, School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, New South Wales 2052, Australia.
Evolution. 2011 Aug;65(8):2145-56. doi: 10.1111/j.1558-5646.2011.01314.x. Epub 2011 May 3.
Because selection is often sex-dependent, alleles can have positive effects on fitness in one sex and negative effects in the other, resulting in intralocus sexual conflict. Evolutionary theory predicts that intralocus sexual conflict can drive the evolution of sex limitation, sex-linkage, and sex chromosome differentiation. However, evidence that sex-dependent selection results in sex-linkage is limited. Here, we formally partition the contribution of Y-linked and non-Y-linked quantitative genetic variation in coloration, tail, and body size of male guppies (Poecilia reticulata)-traits previously implicated as sexually antagonistic. We show that these traits are strongly genetically correlated, both on and off the Y chromosome, but that these correlations differ in sign and magnitude between both parts of the genome. As predicted, variation in attractiveness was found to be associated with the Y-linked, rather than with the non-Y-linked component of genetic variation in male ornamentation. These findings show how the evolution of Y-linkage may be able to resolve sexual conflict. More generally, they provide unique insight into how sex-specific selection has the potential to differentially shape the genetic architecture of fitness traits across different parts of the genome.
由于选择通常依赖于性别，等位基因在一种性别中对适应性可能有积极影响，而在另一种性别中则有负面影响，从而导致基因内的性冲突。进化理论预测，基因内的性冲突可以驱动性限制、性连锁和性染色体分化的进化。然而，性依赖选择导致性连锁的证据是有限的。在这里，我们正式划分了雄鱼（Poecilia reticulata）颜色、尾巴和身体大小的 Y 连锁和非 Y 连锁数量遗传变异的贡献——这些特征以前被认为是性拮抗的。我们表明，这些特征在 Y 染色体上和染色体上都具有很强的遗传相关性，但这些相关性在基因组的两个部分之间的符号和大小上存在差异。正如预测的那样，吸引力的变化与 Y 连锁而不是与雄性装饰的非 Y 连锁遗传变异部分有关。这些发现表明，Y 连锁的进化如何能够解决性冲突。更普遍地说，它们提供了独特的见解，说明性选择如何有可能在基因组的不同部分以不同的方式塑造适应性特征的遗传结构。
