Functional analysis of a symbiotic polydnavirus

共生多DNA病毒的功能分析

• 批准号: 8253184
• 负责人: Gaelen R Burke
• 金额: $ 4.92万
• 依托单位: UNIVERSITY OF GEORGIA
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-03-01 至 2015-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8253184
• 关键词: Address; Adult; Bacteria; Baculoviruses; Binding; Biological Assay; Categories; Cells; DNA Viruses; DNA-Directed RNA Polymerase; Disease; Double Stranded DNA Virus; Evolution; Excision; Family; Female; Genes; Genetic Materials; Genetic Transcription; Genome; Germ Lines; Health; Hymenoptera; Immune; Insecta; Invertebrates; Life; Life Cycle Stages; Literature; Mammals; Messenger RNA; Molecular; Mothers; Names; Organism; Outcome; Phylogenetic Analysis; Play; Polydnaviridae; Polymerase; Process; Production; Proteins; Proviruses; RNA Interference; RNA Polymerase II; Relative (related person); Role; Series; Source; Staging; Symbiosis; Taxon; Technology; Time; Tissues; Viral; Virion; Virus; Wasps; Work; base; chromatin immunoprecipitation; comparative; egg; fitness; innovation; insight; killings; microbial host; microorganism; offspring; parasitism; pathogen; reproductive; research study; trait; transmission process; virology

Many microorganisms have evolved associations with metazoans that range from beneficial symbiosis to pathogenic. While bacteria are well recognized to form beneficial symbiotic associations with metazoans, viruses are usually viewed as non-living, parasitic entities that interact with hosts in ways that only benefit their own transmission and persistence. Yet, many viruses are vertically transmitted, [and are maintained as persistent, nondestructive associations with a wide diversity of hosts, including invertebrates and mammals. Little is currently known about how virus- and host-derived genes interact to regulate viral replication and maintain the symbiotic association. Parasitoid wasps that carry polydnaviruses provide among the strongest examples of viruses evolving into [vertically transmitted, persistent,] beneficial symbionts. [Background studies show that polydnaviruses from braconid wasps evolved from pathogenic nudiviruses but are now beneficial symbionts that persist as integrated proviruses but which replicate at a very specific time in the wasp life cycle to produce virions. However, little is known about how polydnavirus and wasp genes interact to maintain the symbiotic association or how viral replication is regulated. To address this question, I propose to focus on the wasp Microplitis demolitor and its associated polydnavirus named M. demolitor bracovirus (MdBV). My specific aims are to: 1) characterize genes involved in replication of MdBV using massively parallel sequencing technology; 2) identify genes essential for virion formation by conducting a series of functional experiments, and; 3) characterize sequences the viral polymerase binds to assess whether it transcribes only viral or also host genes by conducting chromatin immunoprecipitation (ChIP) assays together with sequencing of captured DNAs. Expected outcomes of my studies will enhance understanding of polydnavirus replication and the roles of virus- and host genes play in this process. [Long term persistence as proviruses combined with episodic replication is a widespread phenomenon in virology of great importance to numerous diseases, yet understanding of the processes that regulate viral activation remain limited to a handful of viral taxa. Thus, more broadly, my study i fundamentally important for understanding how virus and host genomes evolve to form long-term associations, how viruses can evolve to function as symbionts, and how activation/replication of large DNA viruses is regulated at the molecular level.]

许多微生物已经进化出与后生动物的关联，范围从有益的共生到致病的。虽然细菌被公认与后生动物形成有益的共生关系，但病毒通常被视为无生命的寄生实体，它们与宿主相互作用的方式只有利于它们自己的传播和持久性。然而，许多病毒是垂直传播的，并与包括无脊椎动物和哺乳动物在内的各种各样的宿主保持着持久的、非破坏性的联系。目前对病毒和宿主衍生基因如何相互作用来调节病毒复制和维持共生关系知之甚少。携带多dna病毒的寄生蜂是病毒进化成[垂直传播的，持久的]有益共生体的最有力的例子之一。[背景研究表明，来自小蜂的多核酸病毒是从致病性裸病毒进化而来的，但现在是有益的共生体，它们作为整合的原病毒持续存在，但在黄蜂生命周期的一个非常特定的时间复制以产生病毒粒子。然而，关于多核酸病毒和黄蜂基因如何相互作用以维持共生关系或如何调节病毒复制，人们知之甚少。为了解决这个问题，我建议把重点放在黄蜂Microplitis demolition及其相关的多dna病毒M. demolition bracovirus （MdBV）上。我的具体目标是：1)利用大规模平行测序技术表征参与MdBV复制的基因；2)通过一系列功能实验鉴定病毒粒子形成所必需的基因；3)通过染色质免疫沉淀（ChIP）测定和捕获的dna测序，鉴定病毒聚合酶结合的序列，以评估它是只转录病毒基因还是也转录宿主基因。我的预期研究结果将加强对多dna病毒复制以及病毒和宿主基因在这一过程中所起作用的理解。在病毒学中，作为原病毒的长期持续性与间歇性复制相结合是一种广泛存在的现象，对许多疾病都具有重要意义，但对调节病毒激活过程的理解仍然局限于少数病毒分类群。因此，更广泛地说，我的研究对于理解病毒和宿主基因组如何进化形成长期关联，病毒如何进化成为共生体，以及大DNA病毒的激活/复制如何在分子水平上受到调节具有根本性的重要意义。