Sobala Lukasz F, Adler Paul N
Biology Department and Cell Biology Department, University of Virginia, Charlottesville, Virginia, United States of America.
PLoS Genet. 2016 May 27;12(5):e1006100. doi: 10.1371/journal.pgen.1006100. eCollection 2016 May.
The cuticular exoskeleton of insects and other arthropods is a remarkably versatile material with a complex multilayer structure. We made use of the ability to isolate cuticle synthesizing cells in relatively pure form by dissecting pupal wings and we used RNAseq to identify genes expressed during the formation of the adult wing cuticle. We observed dramatic changes in gene expression during cuticle deposition, and combined with transmission electron microscopy, we were able to identify candidate genes for the deposition of the different cuticular layers. Among genes of interest that dramatically change their expression during the cuticle deposition program are ones that encode cuticle proteins, ZP domain proteins, cuticle modifying proteins and transcription factors, as well as genes of unknown function. A striking finding is that mutations in a number of genes that are expressed almost exclusively during the deposition of the envelope (the thin outermost layer that is deposited first) result in gross defects in the procuticle (the thick chitinous layer that is deposited last). An attractive hypothesis to explain this is that the deposition of the different cuticle layers is not independent with the envelope instructing the formation of later layers. Alternatively, some of the genes expressed during the deposition of the envelope could form a platform that is essential for the deposition of all cuticle layers.
昆虫和其他节肢动物的表皮外骨骼是一种具有复杂多层结构的极为通用的材料。我们利用解剖蛹翅以相对纯的形式分离表皮合成细胞的能力，并使用RNA测序来鉴定在成虫翅表皮形成过程中表达的基因。我们观察到表皮沉积过程中基因表达的显著变化，结合透射电子显微镜，我们能够鉴定出不同表皮层沉积的候选基因。在表皮沉积程序中其表达发生显著变化的感兴趣基因中，有编码表皮蛋白、ZP结构域蛋白、表皮修饰蛋白和转录因子的基因，以及功能未知的基因。一个惊人的发现是，一些几乎仅在包膜（最先沉积的最薄外层）沉积期间表达的基因发生突变，会导致原表皮（最后沉积的厚几丁质层）出现严重缺陷。对此一个有吸引力的假说是，不同表皮层的沉积并非独立，包膜指导后续层的形成。或者，在包膜沉积期间表达的一些基因可能形成一个对所有表皮层沉积至关重要的平台。
