Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, United Kingdom.
Am Nat. 2014 May;183(5):711-27. doi: 10.1086/675497. Epub 2014 Mar 12.
The genetic architecture of adaptive traits can reflect the evolutionary history of populations and also shape divergence among populations. Despite this central role in evolution, relatively little is known regarding the genetic architecture of adaptive traits in nature, particularly for traits subject to known selection intensities. Here we quantitatively describe the genetic architecture of traits that are subject to known intensities of differential selection between host plant species in Timema cristinae stick insects. Specifically, we used phenotypic measurements of 10 traits and 211,004 single-nucleotide polymorphisms (SNPs) to conduct multilocus genome-wide association mapping. We identified a modest number of SNPs that were associated with traits and sometimes explained a large proportion of trait variation. These SNPs varied in their strength of association with traits, and both major and minor effect loci were discovered. However, we found no relationship between variation in levels of divergence among traits in nature and variation in parameters describing the genetic architecture of those same traits. Our results provide a first step toward identifying loci underlying adaptation in T. cristinae. Future studies will examine the genomic location, population differentiation, and response to selection of the trait-associated SNPs described here.
适应性状的遗传结构可以反映种群的进化历史，也可以塑造种群间的分化。尽管在进化中起着核心作用，但对于自然适应性状的遗传结构，特别是对于受到已知选择强度影响的性状，人们的了解相对较少。在这里，我们定量描述了 Timema cristinae 竹节虫中受宿主植物物种间已知差异选择强度影响的性状的遗传结构。具体来说，我们使用了 10 个性状的表型测量值和 211,004 个单核苷酸多态性（SNP）进行多基因座全基因组关联作图。我们鉴定出了一些与性状相关的 SNP，这些 SNP 有时可以解释很大一部分性状变异。这些 SNP 与性状的关联强度不同，发现了主效和微效位点。然而，我们没有发现性状在自然分化水平上的差异与描述这些性状遗传结构的参数之间存在关系。我们的研究结果为鉴定 T. cristinae 适应的基因座提供了第一步。未来的研究将研究这里描述的与性状相关的 SNP 的基因组位置、种群分化和对选择的反应。
