Data from: Discriminating selection on lateral plate phenotype and its underlying gene, Ectodysplasin, in threespine stickleback

When a signature of natural selection is discovered on a gene that is pleiotropic or in tight linkage with other genes, it is challenging to determine which of the affected phenotypes is under selection. One way to make progress is to employ methods for analyzing natural selection on correlated traits, including both genotype and phenotype. We used this approach in threespine stickleback to estimate selection on a rapidly evolving trait, lateral armor plates, while controlling for variation at its major underlying gene, Ectodysplasin (Eda), and vice versa. This allowed for independent estimates of selection on lateral plates and on Eda via other traits. Previously, we demonstrated allele frequency changes at Eda in a pond experiment. Here we show that this resulted from selection on both plates and on Eda, implying additional selection on other phenotypic traits affected by the same gene. This represents the first evidence for direct selection on lateral plates independent of selection on the Eda locus and highlights the value of measuring selection on both phenotypes and genotypes in studies of adaptation.当在具有多效性（pleiotropic）或与其他基因紧密连锁（tight linkage）的基因上发现自然选择（natural selection）的特征时，确定受影响的表型（phenotypes）中哪一种处于选择压力之下极具挑战性。一种推进相关研究的可行策略是采用针对相关性状的自然选择分析方法，涵盖基因型（genotype）与表型两类数据。我们将此方法应用于三刺鱼（threespine stickleback），在控制其主要调控基因外异蛋白A（Ectodysplasin，Eda）的变异的同时，估算快速演化性状——侧骨板（lateral armor plates）所受的选择压力，反之亦然。这使得我们能够独立估算侧骨板以及Eda基因通过其他性状所受到的选择压力。此前我们曾在一项池塘实验中证实Eda位点存在等位基因频率（allele frequency）变化，本文研究表明该变化源于侧骨板与Eda基因二者所受的选择，这意味着同一基因所影响的其他表型性状同样承受了额外的选择压力。本研究首次提供了不依赖Eda基因座（locus）选择的、侧骨板直接受选择的证据，并凸显了在适应性演化（adaptation）研究中同时测量表型与基因型选择压力的重要价值。