Abstract：
Silk is a natural protein fiber that is predominantly comprised of fibroin and sericin. In addition, it contains seroins, protease inhibitors, enzymes, and other proteins. We found an ecdysone oxidase BmGMC2, notably, which is specifically and highly expressed only in the silk glands of silkworms (Bombyx mori L.). It is also one of the main components of non-cocoon silk, however, its precise function remains unclear. In this study, we examined the spatiotemporal expression pattern of this protein and obtained a homozygous mutant strain (K-GMC2) using the CRISPR-Cas9 system. Compared to the wild-type strain (WT), the silk production and main silk proteins significantly decreased in the larval stage, and the adhesive strength of native silk proteins decreased in the final instar. Proteomic data indicated the abundance of ribosomal proteins decreased significantly in K-GMC2, differentially expressed proteins (DEPs) were enriched in pathways related to neurodegenerative diseases and genetic information processing, indicating that knockout may lead to a certain degree of cell stress, affecting the synthesis of silk proteins. This study investigated the expression pattern and gene function of ecdysone oxidase BmGMC2 in silk and silk glands, laying the groundwork for understanding the role of enzymes in the production of silk fibers.
摘要：
丝是主要由丝心蛋白和丝胶蛋白组成的天然蛋白质纤维。此外,它含有血清素，蛋白酶抑制剂，酶，和其他蛋白质。我们发现了蜕皮激素氧化酶BmGMC2,仅在蚕（BombyxmoriL.）的丝腺中特异性和高度表达。它也是无茧丝绸的主要成分之一，然而,其确切功能尚不清楚。在这项研究中,我们检查了该蛋白的时空表达模式，并使用CRISPR-Cas9系统获得了纯合突变株（K-GMC2）。与野生型菌株（WT）相比，蚕丝产量和主要蚕丝蛋白在幼虫期显著下降，天然丝蛋白的粘附强度在最终龄中降低。蛋白质组数据表明K-GMC2中核糖体蛋白的丰度显著下降，差异表达蛋白（DEPs）富集在与神经退行性疾病和遗传信息处理相关的通路中，表明敲除可能导致一定程度的细胞应激，影响丝蛋白的合成。本研究研究蜕皮激素氧化酶BmGMC2在蚕丝和丝腺中的表达模式和基因功能。为了解酶在丝纤维生产中的作用奠定基础。
