The mechanistic basis of how symbionts assist vector control

共生体如何协助矢量控制的机制基础

• 批准号: 9759315
• 负责人: Brittany Leigh
• 金额: $ 6.12万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-04-01 至 2022-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9759315
• 关键词: Affect; Animals; Antibodies; Arboviruses; Arthropods; Bacteria; Biochemical; Biocontrols; Biological Assay; Biology; Candidate Disease Gene; Carrier Proteins; Cell Cycle; Cell membrane; Chromatin; Chromosomes; Collection; Competence; Complement Factor B; Culicidae; DNA; DNA Fragmentation; Defect; Dengue; Dengue Virus; Deposition; Deubiquitination; Disease; Drosophila genome; Embryo; Embryonic Development; Encapsulated; Exhibits; Failure; Female; Fertilization; Genes; Hour; Human; Immunoprecipitation; In Vitro; Infection; International; Ligands; Mass Spectrum Analysis; Membrane; Modification; Nuclear; Nuclear Envelope; Partner in relationship; Pattern; Phenotype; Population; Population Replacements; Population Sizes; Process; Prophages; Protamines; Proteins; RNA Viruses; Recommendation; Research; Research Project Grants; Resistance; Sequence Analysis; Spermatogenesis; Stains; System; Testing; Testis; Toxin; Transgenic Organisms; Transmission Electron Microscopy; Ubiquitin; Viral; Virus Replication; Wolbachia; World Health Organization; Zika Virus; Zoonoses; base; comparative; cytochemistry; design; egg; factor A; fly; gene product; in vivo; infancy; interest; male; nuclease; parasitism; particle; pathogen; programs; protein transport; reproductive; segregation; sperm cell; symbiont; tool; transmission process; vector; vector control; vector mosquito

Project Summary: The World Health Organization recently recommended the deployment of Wolbachia-infected mosquitoes for pilot biocontrol efforts that curb the transmission of Zika and dengue viruses to humans. This recommendation is based principally on two facets of Wolbachia biology. First, these maternally-transmitted, endosymbiotic bacteria cause pathogen blocking by altering the competency of mosquitoes to serve as effective hosts for viral replication. Second, Wolbachia alter sperm and egg via a process termed cytoplasmic incompatibility (CI) that is used for population suppression (reduction in mosquito population size) and population replacement (spread of pathogen-blocking Wolbachia into an uninfected population) strategies. Specifically, CI results in embryonic lethality when an infected male mates with an uninfected female. The modified sperm fertilize the uninfected egg, however post-fertilization defects ensue spanning failed replication of paternal DNA, delayed breakdown of paternal nuclear envelope and cell cycle activation, and a failure of segregation of paternal chromosomes. Importantly, the pre-fertilization modifications of sperm remain enigmatic, namely how Wolbachia in the testes express and use the toxin gene products of cytoplasmic incompatibility factors (cif) A and B to establish the onset of CI. As these two gene products represent a breakthrough in the understanding of CI, the central hypothesis of the proposed research is that prophage WO genes, cifA and cifB, encode protein products that escape the Wolbachia membrane in testes to interact with eukaryotic host ligands, ultimately modifying sperm integrity to cause CI. In Aim 1, I will use DNA cytochemistry and enzymatic assays to determine the types of sperm modifications inflicted by the Cif proteins in vivo. In Aim 2, I will investigate localization patterns and potential ligands to test the presumption that viral particles transport the proteins to interact with sperm nuclear DNA. Examinations thus far have yet to yield any mechanistic advance for the initial CI defects, and the rising interest in deploying Wolbachia to curb arbovirus transmission necessitates an explanation of Wolbachia's drive system. If successful, this research will pioneer mechanistic studies of Wolbachia-induced reproductive parasitism, inform Wolbachia's efficacy and delivery as a tool to control diverse zoonotic diseases, and provide multiple lines of evidence for the discovery of the biochemical basis of CI.

项目概要： 世界卫生组织最近建议部署感染沃尔巴克氏体的病毒 蚊子用于试点生物控制工作，遏制寨卡病毒和登革热病毒向人类传播。这 建议主要基于沃尔巴克氏体生物学的两个方面。首先，这些母源传播的， 内共生细菌通过改变蚊子的能力来阻止病原体 病毒复制的有效宿主。其次，沃尔巴克氏体通过称为细胞质的过程改变精子和卵子 用于种群抑制（减少蚊子种群规模）的不相容性 (CI) 和 群体替代（将病原体阻断沃尔巴克氏体传播到未感染群体中）策略。 具体来说，当受感染的雄性与未受感染的雌性交配时，CI 会导致胚胎死亡。这 改造后的精子使未受感染的卵子受精，但受精后缺陷会导致复制失败 父本 DNA 的缺失、父本核膜的延迟分解和细胞周期激活，以及父本 DNA 的失败 父本染色体的分离。重要的是，精子的受精前修饰仍然存在 神秘的，即睾丸中的沃尔巴克氏体如何表达和利用细胞质的毒素基因产物 不相容因素 (cif) A 和 B 以确定 CI 的发生。由于这两个基因产物代表 对 CI 理解的突破，本研究的中心假设是原噬菌体 WO 基因 cifA 和 cifB 编码蛋白质产物，这些蛋白质产物可以逃离睾丸中的沃尔巴克氏体膜，与 真核宿主配体，最终改变精子完整性以引起 CI。在目标 1 中，我将使用 DNA 细胞化学 以及酶法测定以确定体内 Cif 蛋白造成的精子修饰类型。瞄准 2，我将研究定位模式和潜在的配体来测试病毒颗粒的假设 运输蛋白质与精子核 DNA 相互作用。迄今为止的检查尚未得出任何结果 最初 CI 缺陷的机制进展，以及利用沃尔巴克氏体遏制虫媒病毒的兴趣日益浓厚 传输需要对沃尔巴克氏体的驱动系统进行解释。如果成功，这项研究将开创先河 对沃尔巴克氏菌引起的生殖寄生的机制研究，揭示了沃尔巴克氏菌的功效和传递方式 控制多种人畜共患疾病的工具，并为发现该疾病提供多种证据 CI 的生化基础。