Animals widely use minerals and organic components to construct biomaterials with excellent properties, such as teeth, bones, molluscan shells and eggshells. The larvae of the oriental moth, Monema (Cnidocampa) flavescens Walker, secrete silk proteins that combine closely with calcareous minerals to construct a hard cocoon, which is completely different from the mineral-free Bombyx mori cocoon. The cocoons of oriental moths are likely to be the hardest among the cocoons constructed by insect species. The cocoons of oriental moths were found to be mainly composed of calcium oxalates and Asx/Ser/Gly-rich cocoon proteins, but the types of calcium oxalates and cocoon proteins remain to be elucidated. In this study, we provide an in-depth explanation of the inorganic and organic components in the oriental moth cocoon. Microscopy and imaging technologies revealed that the cocoon is composed of mineral crystals, silk fibers and other organic matter. X-ray diffraction and infrared spectral analyses showed that the mineral crystals in the oriental moth cocoon were mainly CaC₂H₂O₄·H₂O. ICP-OES analysis suggested that the mineral crystals in the cocoons were mainly CaC₂H₂O₄·H₂O. LC-MS/MS-based proteomics allowed us to identify 467 proteins from the oriental moth cocoon, including 252 uncharacterized proteins, 87 enzymes, 36 small molecule binding proteins, and 5 silk proteins. Among the uncharacterized proteins, 25 of which were Asn-rich proteins because they contained a high proportion of Asn residues (19.1%–41.4%). Among the top 20 cocoon proteins with the highest abundance, 9 of which were Asn-rich proteins. The qPCR was used to investigate the expression patterns of the major cocoon protein-coding genes. Three fibroins and three Asn-rich proteins were expressed only in the silk gland but not in other tissues. The expression of Asn-rich proteins in the silk gland gradually increased from the anterior silk gland to the posterior silk gland. These findings provide important references for understanding the formation mechanism and mechanical properties of mineralized hard cocoons constructed by oriental moths.

动物广泛使用矿物质和有机成分来构建具有优异性能的生物材料，例如牙齿、骨骼、软体动物的壳和蛋壳。东方蛾Monema (Cnidocampa) flavescens Walker 的幼虫分泌的丝蛋白与钙质矿物质紧密结合，构成坚硬的茧，这与不含矿物质的家蚕完全不同茧。东方蛾的茧可能是昆虫物种构造的茧中最坚硬的。发现东方蛾的茧主要由草酸钙和富含 Asx/Ser/Gly 的茧蛋白组成，但草酸钙和茧蛋白的类型仍有待阐明。在这项研究中，我们对东方蛾茧中的无机和有机成分进行了深入的解释。显微镜和成像技术表明，茧是由矿物晶体、丝纤维和其他有机物质组成的。X射线衍射和红外光谱分析表明，东方蛾茧中的矿物晶体主要为CaC ₂ H ₂ O ₄ ·H ₂O. ICP-OES分析表明茧中的矿物晶体主要是CaC ₂ H ₂ O ₄ ·H ₂O. 基于 LC-MS/MS 的蛋白质组学使我们能够从东方蛾茧中鉴定出 467 种蛋白质，包括 252 种未表征的蛋白质、87 种酶、36 种小分子结合蛋白和 5 种丝蛋白。在未表征的蛋白质中，其中 25 种是富含 Asn 的蛋白质，因为它们含有高比例的 Asn 残基 (19.1%–41.4%)。在丰度最高的前 20 种茧蛋白中，有 9 种是富含 Asn 的蛋白。qPCR 用于研究主要茧蛋白编码基因的表达模式。三种丝心蛋白和三种富含 Asn 的蛋白质仅在丝腺中表达，而在其他组织中不表达。丝腺中富Asn蛋白的表达量从前部丝腺向后部丝腺逐渐增加。