State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China.
Int J Mol Sci. 2020 Mar 10;21(5):1888. doi: 10.3390/ijms21051888.
Osiris is an insect-specific gene family with multiple biological roles in development, phenotypic polymorphism, and protection. In the silkworm, we have previously identified twenty-five Osiris genes with high evolutionary conservation and remarkable synteny among several insects. () is expressed only in the silk gland, particularly in the middle silk gland (MSG). However, the biological function of BmOsi9a is still unknown. In this study, we overexpressed in the silk gland by germline transgene expression. was overexpressed not only in the MSG but also in the posterior silk gland (PSG). Interestingly, could be secreted into the lumen in the MSG but not in the PSG. In the silk fiber, overexpressed interacted with Sericin1 in the MSG, as confirmed by a co-immunoprecipitation assay. The overexpression of altered the secondary structure and crystallinity of the silk fiber, thereby changing the mechanical properties. These results provide insight into the mechanisms underlying silk proteins secretion and silk fiber formation.
Osiris 是一个昆虫特异性基因家族，在发育、表型多态性和保护等多个生物学过程中发挥作用。在蚕中，我们先前鉴定了 25 个 Osiris 基因，它们在进化上高度保守，并且在几种昆虫中具有显著的同源性。（）仅在丝腺中表达，特别是在中丝腺（MSG）中表达。然而，BmOsi9a 的生物学功能尚不清楚。在这项研究中，我们通过生殖细胞转基因表达在丝腺中过表达。在 MSG 中过度表达，但在 PSG 中没有过度表达。有趣的是，在 MSG 中可以分泌到腔中，但在 PSG 中不能分泌到腔中。在丝纤维中，过表达的 与 MSG 中的丝胶蛋白 1 相互作用，这一点通过共免疫沉淀实验得到了证实。的过表达改变了丝纤维的二级结构和结晶度，从而改变了机械性能。这些结果为丝蛋白分泌和丝纤维形成的机制提供了深入的了解。
