Toll样受体 (Toll-like receptors,TLRs)作为古老的免疫受体家族，在体腔动物中广泛存在。但脊椎动物TLRs可以直接识别病原相关分子模式（Pathogen-associated molecular patterns, PAMPs）引发免疫，昆虫Toll参与免疫则必须通过激活细胞介素Spätzle作为配体。我们前期研究发现昆虫Toll9在结构与进化关系上与脊椎动物TLR4相近，暗示昆虫Toll9功能与脊椎动物TLR4相似。本项目以家蚕BmToll9为对象，通过Co-IP、CRISPR/Cas9、BmToll9-TLR4嵌合受体构建及超表达等生物学方法，研究BmToll9是否可以直接识别病原PAMPs及其在家蚕先天免疫中的作用，初步阐明昆虫中也存在可直接识别PAMPs的Toll信号通路。研究结果将丰富我们对昆虫免疫分子调控机制的理解，为天然免疫起源研究提供理论依据。

Toll-related receptors (TLRs) as an oldest immune receptor family, widely exists in vertebrates and invertebrates. TLRs in vertebrates could directly identify pathogen-associated molecular patterns (PAMPs) and active the innate immune, however, the activation of invertebrate Toll involved in immune must through activating Spätzle as ligand. Our previous studies found that the LRR domain of Toll9 in invertebrate and its evolutionary relationship is similar to the vertebrate TLR4, suggesting that the function of Toll9 in invertebrates is similar to TLR4. In this study, silkworm as a model organism, BmToll9 as the target, by CRISPR/Cas9, construction and over expression of BmToll9-TLR4 chimeric receptor to detect whether BmToll9 could directly identify PAMPs and active the innate immune of silkworm like TLR4. The results would enrich our understanding of the insect innate immunity and provide theoretical basis for the origin of innate immune.