Data from: Genome-wide association mapping of phenotypic traits subject to a range of intensities of natural selection in Timema cristinae

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.

适应性性状的遗传结构（genetic architecture）既能反映种群的进化历史，亦可塑造种群间的遗传分化。尽管其在进化研究中居于核心地位，但学界对自然界中适应性性状的遗传结构仍所知有限，针对已知选择强度的相关性状更是如此。
本研究以Timema cristinae竹节虫（Timema cristinae stick insects）为研究对象，对其宿主植物物种间存在差异化选择强度的性状的遗传结构开展定量描述。具体而言，我们结合10个性状的表型测量数据与211,004个单核苷酸多态性（single-nucleotide polymorphisms, SNPs）位点，实施了多座位全基因组关联作图分析。
我们鉴定出少量与性状相关的SNPs，部分位点可解释性状变异的较大比例。不同SNPs与性状的关联强度存在差异，研究同时发现了效应大小各异的主效与微效基因座。然而，我们并未发现自然界中各性状的分化水平变异，与对应性状遗传结构参数的变异之间存在任何关联。
本研究结果为鉴定Timema cristinae竹节虫适应性相关的基因座迈出了第一步。后续研究将进一步考察本研究中鉴定的性状关联SNPs的基因组位置、种群分化特征以及对选择的响应情况。