杆状病毒是一种重要的微生物杀虫剂，其包埋型病毒粒子（ODV）是杀虫毒力和宿主范围的重要决定因子，但ODV囊膜化的关键步骤——核膜内陷出芽形成核内微囊泡的机理至今未阐明。大部分囊泡是在膜的脂筏微区出芽，并需要蛋白寡聚化的驱动。我们的前期研究发现，杆状病毒保守基因ac76的缺失导致重组病毒无法产生核内微囊泡，Ac76蛋白是一个以稳定二聚体形式存在的整合膜蛋白，在感染细胞中定位于内质网、核膜、核内微囊泡等膜结构，生物信息学分析显示该蛋白可能形成更高级形式的寡聚体。据此，我们推测Ac76通过寡聚化驱动核膜的脂筏微区向核质出芽形成核内微囊泡。本研究拟通过分子生物学、病毒学和免疫组化等实验技术首次揭示杆状病毒诱导的内核膜脂筏形成以及Ac76的寡聚化，并分析二者与核膜弯曲出芽形成核内微囊泡的关系，以解析核膜弯曲出芽的生物学过程，为进一步阐明这种病毒的增殖机理并为遗传改良杆状病毒杀虫剂提供重要的理论基础。

Baculoviruses are important microbial insecticides. The occlusion-derived virion (ODV) of baculovirus is an important determinant factor for the insecticidal virulence and host range. ODV envelopes are derived from intranuclear membranes. So far, the mechanism by which the nuclear membrane buds into nucleoplasm to form the precursor of the ODV envelopes, so called intranuclear microvesicles, remains unknown. Vesicles result from the budding of the specific sites of membranes, and most of these specific sites are lipid raft microdomains. Meanwhile, the oligomerization of membrane proteins plays an important role during this process. Our previous study showed that the deletion of baculovirus conserved gene ac76 affects intranuclear microvesicle formation. Ac76 is an integral membrane protein and exists as a stable homodimer. It is localized to the plasma membrane, endoplasmic reticulum, nuclear membrane and intranuclear microvesicles. Bioinformatics analysis showed that Ac76 may form higher-order oligomers. So we propose a model in which Ac76 drives the bending and budding of lipid raft platforms to form intranuclear microvesicles via its oligomerization. In this project, we plan to demonstrate whether baculovirus infection is able to induce the formation of lipid raft on the inner nuclear membrane and whether Ac76 inserts into the lipid raft of nuclear membrane in the form of oligomer, and analyze the role that the oligomerization of Ac76 and the formation of lipid raft in the nuclear membrane play in the bending and budding of nuclear membrane. This study will shed important light on the understanding of ODV envelopment and benefit the genetic modification of baculovirus insecticides.