Genome sequence and silkomics of the spindle ermine moth, Yponomeuta cagnagella, representing the early diverging lineage of the ditrysian Lepidoptera

Many lepidopteran caterpillars produce silk, cocoons, feeding tubes, or nests for protection from predators and parasites. Yet, the number of lepidopteran species whose silk composition has been studied in detail is very small, because the genes encoding the major structural silk proteins tend to be large and repetitive, making their assembly and sequence analysis difficult. Here we have analyzed the silk of Yponomeuta cagnagella, which represents one of the early diverging lineages of the ditrysian Lepidoptera thus improving the coverage of the order. To obtain a comprehensive list of the Y. cagnagella silk genes, we sequenced, assembled, and annotated the draft genome using Oxford Nanopore and Illumina technologies. The 626 Mb assembly with N50 of 96.5 kb contained 96.9% insect orthologs recovered by BUSCO and 30,003 predicted gene models. We then used a silk-gland transcriptome and a silk proteome to identify major silk components and verified the tissue specificity of the expression...许多鳞翅目（Lepidoptera）幼虫可纺丝、构筑茧壳、取食管或巢穴，以此抵御天敌与寄生虫的侵扰。然而，目前被深入解析丝蛋白组成的鳞翅目物种数量极少——这是由于编码主要结构丝蛋白的基因往往序列冗长且重复度极高，导致其组装与序列分析工作难度颇大。本研究针对Yponomeuta cagnagella的丝蛋白展开分析，该物种隶属于双孔类鳞翅目（Ditrysian Lepidoptera）的早期分化支系之一，此举有效提升了该目昆虫的研究覆盖范围。为全面获取Y. cagnagella的丝蛋白基因全集，本研究借助牛津纳米孔（Oxford Nanopore）与Illumina测序技术，对其草稿基因组进行了测序、组装与注释。该基因组组装大小为626 Mb，N50值达96.5 kb；经通用单拷贝同源基因聚类评估工具（BUSCO，Benchmarking Universal Single-Copy Orthologs）评估，其可覆盖96.9%的昆虫直系同源基因，共预测得到30003个基因模型。随后，本研究结合丝腺转录组与丝蛋白组数据，鉴定出该物种的主要丝蛋白组分，并验证了其组织表达特异性……