Functional Analysis of Insect Molting Fluid Proteins on the Protection and Regulation of Ecdysis

作者：Jie Zhang, Anrui Lu, Lulu Kong, Qiaoli Zhang, Erjun Ling · 发表于：Journal of Biological Chemistry · 年份：2014 · DOI：10.1074/jbc.m114.599597 · 被引用次数：108 · 研究领域：Neurobiology and Insect Physiology Research、Insect and Arachnid Ecology and Behavior、Insect and Pesticide Research

Molting fluid accumulates between the old and new cuticles during periodical ecdysis in Ecdysozoa. Natural defects in insect ecdysis are frequently associated with melanization (an immunity response) occurring primarily in molting fluids, suggesting that molting fluid may impact immunity as well as affect ecdysis. To address this hypothesis, proteomic analysis of molting fluids from Bombyx mori during three different types of ecdysis was performed. Many proteins were newly identified, including immunity-related proteins, in each molting fluid. Molting fluids inhibited the growth of bacteria in vitro . The entomopathogenic fungi Beauveria bassiana , which can escape immune responses in feeding larvae, is quickly recognized by larvae during ecdysis, followed by melanization in molting fluid and old cuticle. Fungal conidia germination was delayed, and no hyphae were detected in the hemocoels of pharate instar insects. Molting fluids protect the delicate pharate instar insects with extremely thin cuticles against microorganisms. To explore the function of molting fluids in ecdysis regulation, based on protein similarity, 32 genes were selected for analysis in ecdysis regulation through RNAi in Tribolium castaneum , a model commonly used to study integument development because RNAi is difficult to achieve in B. mori . We identified 24 molting proteins that affected ecdysis after knockdown, with different physiological functions, including old cuticle protein recycling, molting flu...