Data from: Epidermal growth factor receptor and transforming growth factor-ß signaling contributes to variation for wing shape in Drosophila melanogaster

Wing development in Drosophila is a common model system for the dissection of genetic networks and their roles during development. In particular, the RTK and TGF-ß regulatory networks appear to be involved with numerous aspects of wing development, including patterning, cell determination, growth, proliferation, and survival in the developing imaginal wing disc. However, little is known as to how subtle changes in the function of these genes may contribute to quantitative variation for wing shape, per se. In this study 50 insertional mutations, representing 43 loci in the RTK, Hedgehog, TGF-ß pathways, and their genetically interacting factors were used to study the role of these networks on wing shape. To concurrently examine how genetic background modulates the effects of the mutation, each insertion was introgressed into two wild-type genetic backgrounds. Using geometric morphometric methods, it is shown that the majority of these mutations have profound effects on shape but not size of the wing when measured as heterozygotes. To examine the relationships between how each mutation affects wing shape hierarchical clustering was used. Unlike previous observations of environmental canalization, these mutations did not generally increase within-line variation relative to their wild-type counterparts. These results provide an entry point into the genetics of wing shape and are discussed within the framework of the dissection of complex phenotypes.果蝇（Drosophila）的翅膀发育是解析遗传网络及其在发育过程中功能的经典模式系统。其中，受体酪氨酸激酶（Receptor Tyrosine Kinase, RTK）与转化生长因子-β（Transforming Growth Factor-β, TGF-β）调控网络参与翅膀发育的诸多环节，包括发育中成虫翅盘（imaginal wing disc）的模式形成、细胞命运决定、生长、增殖与存活。然而，目前对于这些基因功能的细微变化如何直接影响翅膀形状的数量性状变异仍知之甚少。本研究选取了50个插入突变（insertional mutation），覆盖受体酪氨酸激酶、刺猬因子（Hedgehog, Hh）、转化生长因子-β通路及其遗传互作因子的43个基因座（loci），以探究这些调控网络对翅膀形状的调控作用。为同时探究遗传背景（genetic background）如何调控突变的效应，我们将每个插入突变分别回交导入两种野生型遗传背景中。借助几何形态测量法（geometric morphometric methods）分析，结果显示：绝大多数此类杂合子（heterozygote）突变对翅膀形状具有显著影响，但不改变翅膀大小。为解析各突变对翅膀形状的影响模式间的关联，本研究采用了层次聚类（hierarchical clustering）方法。与此前报道的环境表型缓冲（environmental canalization）现象不同，相较于野生型对照，这些突变并未普遍提升品系内的变异水平。本研究结果为解析翅膀形状的遗传基础提供了切入点，并将结合复杂表型解析的研究框架展开讨论。