Data from: Quantitative genetic variance in experimental fly populations evolving with or without environmental heterogeneity

Heterogeneous environments are typically expected to maintain more genetic variation in fitness within populations than homogeneous environments. However, the accuracy of this claim depends on the form of heterogeneity as well as the genetic basis of fitness traits and how similar the assay environment is to the environment of past selection. Here we measure quantitative genetic variance for three traits important for fitness using replicated experimental populations of Drosophila melanogaster evolving under four selective regimes: constant salt-enriched medium (Salt), constant cadmium-enriched medium (Cad), and two heterogeneous regimes that vary either temporally (Temp) or spatially (Spatial). As theory predicts, we found that Spatial populations tend to harbor more genetic variation than Temp populations or those maintained in a constant environment that is the same as the assay environment. Contrary to expectation, Salt populations tend to have more genetic variation than Cad populations in both assay environments. We discuss the patterns for quantitative genetic (QG) variances across regimes in relation to previously reported data on genome-wide sequence diversity. For some traits, the QG patterns are similar to the diversity patterns of ecological selected SNPs whereas the QG patterns for some other traits resembled that of neutral SNPs.

相较于均质环境，异质环境通常被认为更能在种群内维持更多的适合度遗传变异。然而，这一论断的准确性取决于异质性的表现形式、适合度性状的遗传基础，以及测定环境与过往选择环境的相似程度。本研究以在四种选择性环境模式下演化的黑腹果蝇（Drosophila melanogaster）重复实验种群为材料，针对三类重要的适合度性状测定了其数量遗传方差；四种环境模式分别为：恒定高盐培养基（Salt）、恒定镉污染培养基（Cad），以及两种分别随时间（Temp）或空间（Spatial）变化的异质环境模式。正如理论预测的那样，本研究发现空间异质环境下的种群所携带的遗传变异量往往高于时间异质种群，以及与测定环境一致的恒定环境种群。但与预期相悖的是，在两种测定环境中，高盐环境种群的遗传变异量均高于镉污染环境种群。本研究结合已发表的全基因组序列多样性数据，探讨了不同选择模式下的数量遗传（quantitative genetic, QG）方差分布模式。部分性状的数量遗传方差分布模式与受生态选择的单核苷酸多态性（Single Nucleotide Polymorphisms, SNPs）多样性模式一致，而另有部分性状的该分布模式则与中性单核苷酸多态性的分布模式相似。