MOLECULAR DETERMINANTS OF BACULOVIRUS HOST SPECIFICITY

本研究的目的是鉴定和表征杆状病毒 控制宿主特异性的基因这将有助于确定 杆状病毒的寄主和组织嗜性的遗传基础。长 长期目标是开发控制害虫的改进方法。 杆状病毒，无脊椎动物特异性病原体，感染广泛的 昆虫，包括疾病媒介，是一种有吸引力的替代品， 化学杀虫剂由于对化学物质的抵抗力增强， 杀虫剂和抗药性寄生虫的发展，新的 需要控制媒介昆虫的策略。受限主机和 杆状病毒所表现出的组织嗜性限制了它们的用途， 杀虫剂例如，在蚊子中观察到的杆状病毒 只存在于中肠组织中杆状病毒技术 AcMNPV是一种具有异常广泛宿主范围的杆状病毒， 用于研究杆状病毒分子生物学的模型系统。到 通过实验解决宿主和组织特异性的问题， 将使用遗传方法。基因有助于广泛的宿主 将通过突变AcMNPV来鉴定AcMNPV中观察到的范围， 在组织培养中分离宿主范围减少的突变体。后 突变体的初步特征，突变的基因将 分子克隆和测序。另外的实验以确定 在杆状病毒感染中突变基因的正常功能将 设计和执行。这些实验将由 突变体表型的观察和可能的 功能，基于对蛋白质和DNA序列的分析。这些 研究将从两个方面促进改进昆虫控制。 首先，可以开发出针对特定病毒的改良病毒杀虫剂。 昆虫第二，因为病毒反映了它们的正常功能， 病毒控制宿主范围的机制可能 提出了用于昆虫控制的另外的新方法。

The objective of this study is to identify and characterize baculovirus genes that control host specificity. This will contribute to determining the genetic basis of host and tissue tropisms in baculoviruses. The long term goal is to develop improved methods for controlling insect pests. Baculoviruses, invertebrate specific pathogens that infect a wide range of insects, including disease vectors, are an attractive alternative to chemical insecticides. Because of increased resistance to chemical insecticides and the development of drug resistant parasites, new strategies for controlling vector insects are needed. Restricted host and tissue tropisms exhibited by baculoviruses limit their usefulness as insecticides. For example, baculoviruses observed in mosquitoes are seen only in midgut tissues. Autographa californica nuclear polyhedrosis (AcMNPV), a baculovirus with an unusually broad host range, serves as a model system for studying the molecular biology of baculoviruses. To address the problem of host and tissue specificity experimentally, a genetic approach will be used. Genes that contribute to the broad host range observed in AcMNPV will be identified by mutating AcMNPV and isolating mutants that have reduced host range in tissue culture. After initial characterization of the mutants, the mutated genes will he molecularly cloned and sequenced. Additional experiments to determine the normal function of the mutated genes in baculovirus infections will be designed and executed. These experiments will be determined by observations of the mutant phenotypes and predictions of possible function, based on analysis of the protein and DNA sequences. These studies will contribute towards improved insect control in two ways. First, improved viral insecticides could be developed for specific insects. Second, because viruses reflect the normal functions of their hosts, the mechanisms used by the virus to control host range might suggest additional novel approaches for insect control.