Section of Biology and Environmental Science, Department of Chemistry and Bioscience, Aalborg University, Fredrik Bajers Vej 7H, 9220 Aalborg E, Denmark.
School of Biosciences, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria 3052, Australia.
Evolution. 2018 Jan;72(1):136-152. doi: 10.1111/evo.13391. Epub 2017 Nov 28.
Trait variation is normally separated into genetic and environmental components, yet genetic factors also control the expression of environmental variation, encompassing plasticity across environmental gradients and within-environment responses. We defined four components of environmental variation: plasticity across environments, variability in plasticity, variation within environments, and differences in within-environment variation across environments. We assessed these components for cold tolerance across five rearing temperatures using the Drosophila melanogaster Genetic Reference Panel (DGRP). The four components were found to be heritable, and genetically correlated to different extents. By whole genome single marker regression, we detected multiple candidate genes controlling the four components and showed limited overlap in genes affecting them. Using the binary UAS-GAL4 system, we functionally validated the effects of a subset of candidate genes affecting each of the four components of environmental variation and also confirmed the genetic and phenotypic correlations obtained from the DGRP in distinct genetic backgrounds. We delineate selection targets associated with environmental variation and the constraints acting upon them, providing a framework for evolutionary and applied studies on environmental sensitivity. Based on our results we suggest that the traditional quantitative genetic view of environmental variation and genotype-by-environment interactions needs revisiting.
性状变异通常分为遗传和环境因素，但遗传因素也控制着环境变异的表达，包括环境梯度和环境内的可塑性以及环境内的响应变化。我们定义了环境变异的四个组成部分：跨环境的可塑性、可塑性的可变性、环境内的变异以及跨环境的环境内变异的差异。我们使用黑腹果蝇遗传参考面板（DGRP）在五个饲养温度下评估了对耐寒性的这些组成部分。发现这四个组成部分是可遗传的，并且在不同程度上遗传相关。通过全基因组单标记回归，我们检测到控制这四个组成部分的多个候选基因，并显示出影响它们的基因之间的有限重叠。使用二进制 UAS-GAL4 系统，我们在不同的遗传背景下对影响环境变异的四个组成部分的候选基因子集的功能进行了验证，并确认了从 DGRP 获得的遗传和表型相关性。我们描绘了与环境变异和对其起作用的约束相关的选择目标，为环境敏感性的进化和应用研究提供了框架。基于我们的结果，我们建议对环境变异和基因型-环境相互作用的传统数量遗传观点进行重新审视。
