The Molecular Biology of Polydnavirus Gene Organization and Expression in Campoletis Sonorensis and Heliothis Virescens

寄生蜂能否成功寄生于寄主昆虫，取决于多dna病毒在产卵过程中随寄主卵的转移和表达。该病毒及其生命周期在两个主要方面是独特的：1)它是一种DNA动物病毒，具有复杂的多片段基因组，由至少28个共价封闭的双链DNA组成；2)该病毒与寄生蜂存在明显的共生关系，并在被寄生宿主体内引起一定的变化，有效地破坏宿主的细胞免疫防御，有利于寄生蜂的成功发育。在分子水平上研究最彻底的寄生虫-病毒-宿主系统是sonorensis Campoletis sonorensis黄蜂及其病毒（CsV）和寄主昆虫Heliothis virescens。将继续研究多部基因组的遗传组织。这将通过物理制图和转录产物在黄蜂昆虫和被寄生宿主的制图来完成。一旦定位出那些被认为是干扰被寄生昆虫细胞防御系统的重要因素的基因，将被克隆并研究病毒编码基因产物的功能和特性。确定该病毒在被寄生昆虫中破坏细胞免疫应答的具体功能及其机制（靶点和作用）是本研究的最终目标。这将导致对昆虫免疫防御的阐明，以及如何操纵这些防御来控制对公共卫生或农业有重要意义的昆虫，或控制昆虫传播动植物病原体的能力。

The successful parasitism by a parasitic insect wasp of its host insect is dependent upon the transfer and expression of a polydnavirus along with the parasite's egg during oviposition. The virus and its life cycle are unique in two major aspects: 1) it is a DNA animal virus with a complex multipartite genome consisting of at least 28 doublestranded, covalaently closed DNAs; 2) the virus has an apparent symbiotic relationship with the wasp insect and causes certain changes in the parasitized host effectively compromising the host's cellular immune defenses to favor the successful development of the parasite. The parasitic Campoletis sonorensis wasp, its virus (CsV), and the host insect, Heliothis virescens, is the most thoroughly studied parasite-virus-host system at the molecular level. Studies will be continued on mapping the genetic organization of the multipartite genome. This will be done by physical mapping and a mapping of the transcription products in the wasp insect and parasitized host. Once mapped those genes believed to be important factors interfering with the parasitized insect's cellular defense system will be cloned and studied for function and identity of viral encoded gene products. It is the ultimate goal of the research to identify the specific functions of the virus and mechanisms (target sites and effects) in the parasitized insect abrogating cellular immune response. This should lead to an elucidation of insect immunity defenses and how these may be manipulated for the control of insects of public health or agricultural importance, or for control of the ability of insects to transmit animal and plant pathogens.