基于记忆剥夺假说下Wolbachia诱发赤眼蜂过寄生行为机制研究

赤眼蜂是多种农林害虫的重要寄生性天敌。已发现共生菌Wolbachia（简称“沃菌”）感染赤眼蜂可促使雌蜂进行过寄生，即在被寄生寄主内再次产卵，但其机理仍毫无所知。已知赤眼蜂通过后天学习调节其产卵行为以避免把卵浪费于低品质寄主（如已被寄生的寄主）上。记忆剥夺假说认为感染沃菌可能使赤眼蜂丧失记忆能力而无法辨别被寄生寄主，进而引发过寄生行为。为检验该假说，本项目以松毛虫赤眼蜂为对象，分别建立健康对照、沃菌感染、渐渗杂交和抗生素治愈等纯系，根据转录组数据鉴定和克隆记忆关键基因TdCREB，通过RNAi沉默该基因和饲喂记忆抑制剂两种方式处理赤眼蜂，通过观测赤眼蜂的学习记忆能力和过寄生频率等行为特征，并测定TdCREB表达及相关蛋白含量，解析沃菌感染诱发赤眼蜂过寄生行为分子机理。本研究有望深刻认识沃菌影响宿主生殖行为的新方式，加深沃菌与赤眼蜂互作关系的理解，也可为赤眼蜂规模化繁殖及应用提供理论支撑。

Trichogramma is an important parasitoid group against multiple species of agricultural and forest pests. Previous studies revealed that Wolbachia-infected Trichogramma wasps often deposit their eggs on the hosts that have been parasitized, which is called superparasitism. Memory retention hypothesis implies that the infected female wasps unable to discriminate parasitized hosts due to the memory loss induced by Wolbachia. To test the hypothesis, Trichogramma dendrolimi is used as the model in this program. The natural uninfected line, Wolbachia-infected line, introgression line, and antibiotic-treated line have been established and will be examined. The key gene of memory of T. dendrolimi have been identified and cloned based on transcriptome database of T. dendrolimi. To investigate the mechanisms of superparasitic beahavior induced by Wolbachia, memory inhibitors and RNAi method are applied to artificially deprive memory of female wasps, the learning-memory capacity, frequency of superparasitism, and experssion level of TdCREB and content of related protein will be observed or measured. The program aims to reveal the new insight of the manipulation of Wolbachia on Trichogramma wasps. The results will not only be helpful to bridge the gaps of the interaction of Wolbachia and Trichogramma, but also provide the reference for the mass-rearing and application of Trichogramma wasps.