杆状病毒研究的焦点是对蚕桑产业的危害和自然界昆虫种群密度的控制，BmNPV入侵复制的分子机制等研究进展迅速，但有待系统阐释。本项目拟将生物冷冻电镜技术(cryoEM)引入到BmNPV的结构生物学研究，开展基于高分辨病毒结构的入侵机制解析。应用300kV的cryoEM收集BmNPV的BV、ODV病毒粒子或核衣壳等图像数据，进行“杆状、螺旋”BmNPV病毒的高分辨三维重构，从而解析病毒识别入侵相关蛋白/活性位点的近原子分辨结构，为BmNPV病毒受体筛选提供“蛋白结构”基础。同时以GP64病毒蛋白为例，通过pull-down等技术鉴定GP64病毒蛋白的结合受体，建立基于BmNPV高分辨结构的“病毒-细胞”互作研究新策略，为“病毒结构-受体蛋白”双向阐释BmNPV入侵机制奠定基础，有助于家蚕病毒病防控和抗病育种的研究，也可为痘病毒、对虾白斑病毒等相关病毒的启动感染、双相复制机制研究提供借鉴。

Although much of the early interest in baculoviruses was due to the threat they posed to the silk industry, baculoviruses play a major role in the control of natural insect populations. The molecular mechanism of BmNPV invasion and replication is progressing rapidly, but it needs to be explained systematically. The present project intends to introduce cryoEM into the structural biology of BmNPV and the study on the invasion mechanism based on virus high resolution structure. Firstly, the electronic data of BV, ODV or nucleocapsid of BmNPV will be taken by 300 kV cryoEM. Then, high resolution 3D reconstruction of BmNPV will be established using IHRSR and RELION. Finally, nearly atomic resolution structure of the active sites and viral protein related to the BmNPV invasion will be analyzed for providing a "structure" basis to screening the virus receptor. Meanwhile, the binding receptor protein of GP64 was identified by molecular biological experiment. A new method of "virus-cell" interaction based on BmNPV nearly atomic resolution structure was established to lay a foundation for the bidirectional interpretation of "virus structure-receptor protein". The results will accelerate the process of disease resistance breeding and prevention of virus disease of silkworm. It can also be used as a reference for the study of the initiation infection and double phase replication mechanism of nudivirus, panaeus monodon, and etc.