Data from: Evidence for canalization of Distal-less function in the leg of Drosophila melanogaster

A considerable body of theory pertaining to the evolution of canalization has emerged recently, yet there have been few empirical investigations of their predictions. To address this, patterns of canalization and trait correlation were investigated under the individual and joint effects of the introgression of a loss-of-function allele of the Distal-less gene and high-temperature stress on a panel of iso-female lines. Variation was examined for number of sex comb teeth and the length of the basi-tarsus on the pro-thoracic leg of male Drosophila melanogaster. I demonstrate that whereas there is evidence for trait canalization, there is no evidence to support the hypothesis of the evolution of genetic canalization as a response to microenvironmental canalization. Furthermore, I demonstrate that although there are genetic correlations between these traits, there is no association between their measures of canalization. I discuss the prospects of the evolutionary lability of the Distal-less gene within the context of changes in genetic variation and covariation.

近年来，围绕渠化（canalization）的演化形成了相当体量的理论体系，但针对这些理论预测开展的实证研究却寥寥无几。为填补这一研究空白，本研究以一组黑腹果蝇（Drosophila melanogaster）的等雌系（iso-female lines）为材料，分别探究了Distal-less基因（Distal-less gene）功能丧失等位基因渐渗、高温胁迫及其联合效应对渠化模式与性状相关性的影响。研究考察了雄性黑腹果蝇前胸足（pro-thoracic leg）上的性梳齿（sex comb teeth）数量与基跗节（basi-tarsus）长度的变异情况。本研究证实，尽管存在性状渠化的相关证据，但并未发现支持"遗传渠化的演化是对微环境渠化的响应"这一假说的实验依据。此外，本研究还发现，尽管这两个性状之间存在遗传相关（genetic correlations），但其渠化程度的测量指标之间并无关联。本文还结合遗传变异与遗传协变的变化背景，探讨了Distal-less基因的进化易变性（evolutionary lability）的研究前景。