Determining the evolutionary forces shaping genotype-by-environment interactions

项目摘要 了解进化力量如何塑造数量性状的遗传变异至关重要 用于确定遗传疾病在人群中的患病率。尽管多次 例如，基因型与环境的相互作用（GxE）对于维持 生物学和医学重要特征的变异，我们缺乏对生物学和医学重要特征的作用的明确认识。 GxE在形成遗传变异和形成GxE的进化过程中所起的作用。 特别是两个广泛的过程可能有助于GxE：局部适应塑料反应 以及在不同环境中选择性约束的变化。 拟议的工作评估这两个演变过程的重要性，在塑造 GxE在自然人群中。我们将利用大型基因组，转录组和表型 系统中的数据集，其中相同的基因型可以在多个 生物现实环境。首先，我们将使用以前开发的测试的扩展 由PI寻找当地适应性形成遗传变异的证据， 为GXE做贡献接下来，我们将开发一个新的分析，寻找 等位基因频率和环境特异性效应大小，与假设一致， 选择性约束形状GxE的变化。最后，我们将测试假设，放松 对很少表达的塑性反应的选择性约束限制了自适应的进化， 可塑性，通过测试减少对基因的负选择的证据， 在特定的环境中。 总的来说，这项工作将确定形成GxE的进化过程，填补一个关键的空白 在我们对数量性状变异的维持的理解中， 这些方法将对各种系统的研究人员有用。

PROJECT SUMMARY Understanding how evolutionary forces shape genetic variation for quantitative traits is crucial for determining the prevalence of genetic disease in human populations. Despite numerous examples that genotype-by-environment interactions (GxE) are important for the maintenance of variation for biologically and medically important traits, we lack a clear understanding of the role that GxE plays in shaping genetic variation and of the evolutionary processes that shape GxE. In particular two broad processes could contribute to GxE: local adaptation for plastic responses and variation in selective constraint across environments. The proposed work evaluates the importance of these two evolutionary processes in shaping GxE in natural populations. We will leverage large genomic, transcriptomic, and phenotypic datasets in systems where identical genotypes can be phenotyped across multiple biologically-realistic environments. First, we will use an extension of a test previously developed by the PI to look for evidence of local adaptation shaping genetic variation for plastic responses, contributing to GxE. Next, we will develop a new analysis looking for a covariance between allele frequency and environment-specific effect sizes, consistent with the hypothesis that variation in selective constraint shapes GxE. Finally, we will test the hypothesis that relaxed selective constraint on rarely-expressed plastic responses limits the evolution of adaptive plasticity by testing for evidence of reduced negative selection on genes that are only expressed in specific environments. Overall, this work will determine the evolutionary processes that shape GxE, filling a crucial gap in our understanding of the maintenance of variation for quantitative traits and providing methods that will be useful to researchers in a variety of systems.