NPV病毒对宿主昆虫行为调控机理研究

The host insects strongly changed their behavior after an infection by Baculovirus, especially by nucleopolyhedrovirus (NPV). The most classic example is: the Lepidopteran larvae that infected by NPV were climbing to the top of a tree and died upside down on the branches of tree top. So the insect virus diease was called as "Tree top diease" at earlier time since insect virus was found by scientists. And the mechanism of how insect hosts change thier behavior is still unclear. This study aimed at the mechanism of host insect behavior change by using bioassay, co-transcriptome and iTRAQ for infected larvae and uninfected control larvae of Lymantria dispar. All the possiblly involved genes were subjected to further identification and confirmation by RNAi and gene knock out techniques with single or group genes to understand the mechanism of larvae behavior regulation by NPV. It would also shed a light on the understanding of interaction between pathogens and host animals. And it provided the possibility for genetic egineering that facilitated insect virus to expand the infection diameter to kill more insect pests in forest.

昆虫病毒感染宿主后，能够引起宿主昆虫行为发生显著变化，其中最经典的一个例子就是：感染了杆状病毒的鳞翅目幼虫会爬到树体顶端枝条上、倒挂而死，因此昆虫病毒病在以前又叫“树顶病”，但为何昆虫染病后会出现如此反常行为，其机理不明。本项目拟利用舞毒蛾和舞毒蛾核型多角体病毒（LdNPV）为研究对象，通过对LdNPV病毒感染和对照试虫进行生物测定、共转录组分析和 iTRAQ分析，筛选出参与LdNPV感染后参与宿主行为调控相关基因，对筛选出调控感病宿主行为基因进行RNAi验证、及通过不同基因组合删除与反向验证，最终确定参与宿主行为调控的基因以及它们之间的相互关系，阐明其作用途径，旨在为深入探讨NPV病毒对宿主昆虫行为调控机理提供必要的支撑数据，为理解病原微生物调控动物行为的机理提供重要基础数据；同时在林业生产实践中，也有望为利用基因工程修饰病毒、通过增强爬高行为来扩大病毒传播范围、提高昆虫病毒生防效果。

昆虫病毒感染宿主后，能够引起宿主昆虫行为发生显著变化，其中最经典的一个例子就是：感染了杆状病毒的鳞翅目幼虫会爬到树体顶端枝条上、倒挂而死，因此昆虫病毒病在以前又叫“树顶病”，但为何昆虫染病后会出现如此反常行为，其机理不明。本项目拟利用舞毒蛾和舞毒蛾核型多角体病毒（LdNPV）为研究对象，深入探讨了NPV病毒对宿主昆虫行为调控机理。通过系统地研究，筛选出了参与“树顶病”形成的相关基因2013个、基因通路269个，并对其中的生物节律信号途径、光信号调控、凋亡相关PI3K/Akt途径进行了功能验证。发现“树顶病”的发生受生物节律途径调控，并与此途径密切相关的光信号是关键的外源光诱导因素导致被感染幼虫向上爬而不是其他方向。最终受感染幼虫爬高而死的原因是病毒感染诱导的细胞凋亡途径，是触发“树顶病”的关键环节之一。这些科学数据为最终阐明“树顶病”形成的机理提供了重要基础。