Data from: Epidermal growth factor receptor and transforming growth factor-beta 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-beta 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-beta 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）翅膀发育是解析遗传网络及其在发育进程中功能的常用模型体系。其中，受体酪氨酸激酶（Receptor Tyrosine Kinase，RTK）、转化生长因子-β（Transforming Growth Factor-beta，TGF-β）等调控网络参与了翅膀发育的诸多环节，包括正在发育的成虫翅盘（imaginal wing disc）中的模式形成、细胞定型、生长、增殖与存活。然而，对于这些基因功能的细微变化如何直接导致翅膀形状的数量变异，目前尚不清楚。本研究选用了50个插入突变，涵盖RTK、Hedgehog、TGF-β信号通路及其遗传互作因子的43个基因座，以探究这些网络在翅膀形状调控中的作用。为同时探究遗传背景如何调控突变的表型效应，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 Morphometrics），研究发现大多数处于杂合状态的此类突变对翅膀形状具有显著影响，但不改变翅膀大小。为探究各突变对翅膀形状的影响模式之间的关联，本研究采用了层级聚类分析方法。与此前关于环境缓冲（environmental canalization）的研究结果不同，相较于其野生型对照，此类突变总体上并未增加品系内的变异。本研究结果为解析翅膀形状的遗传机制提供了切入点，并将结合复杂表型解析的研究框架展开讨论。