The mechanistic basis of how symbionts assist vector control

项目总结： 世界卫生组织最近建议部署感染沃尔巴克氏菌的 蚊子生物控制试点工作，以遏制寨卡病毒和登革热病毒向人类的传播。这 推荐主要基于沃尔巴克氏菌生物学的两个方面。首先，这些通过母体传播的， 内共生菌通过改变蚊子作为病原体的能力而引起病原体堵塞 病毒复制的有效宿主。其次，沃尔巴克氏杆菌通过一种被称为细胞质的过程改变精子和卵子 用于种群抑制(减少蚊子种群数量)的不亲和性(CI)和 种群置换(病原体传播，阻止沃尔巴克氏菌进入未受感染的种群)策略。 具体地说，当感染的男性与未感染的女性交配时，CI会导致胚胎死亡。这个 改良的精子使未感染的卵子受精，但受精后的缺陷会导致复制失败 父亲的DNA，父亲的核膜延迟分解和细胞周期激活，以及 父系染色体的分离。重要的是，精子受精前的修改仍然存在 谜团，即沃尔巴克氏菌是如何在睾丸中表达和利用胞质毒素基因产物的 血型不合因子(CIF)A和B以确定CI的发病。因为这两种基因产物代表着一种 在对CI的理解上的突破，拟议研究的中心假设是前噬菌体WO CifA和cifB基因编码的蛋白质产物逃离了睾丸中的沃尔巴克氏菌膜而与之相互作用 真核宿主配体，最终改变精子的完整性，导致CI。在目标1中，我将使用DNA细胞化学 以及酶分析，以确定Cif蛋白在体内引起的精子修饰的类型。在AIM 2，我将调查定位模式和潜在的配体，以测试病毒颗粒 运输这些蛋白质与精子核DNA相互作用。到目前为止，检查还没有产生任何 最初CI缺陷的机械性进展，以及部署Wolbachia遏制虫媒病毒的兴趣日益高涨 传播需要对沃尔巴克氏杆菌的驱动系统进行解释。如果成功，这项研究将是 沃尔巴克氏菌诱导生殖寄生的机制研究，告知沃尔巴克氏菌的疗效和交付作为 一种控制各种人畜共患疾病的工具，并为发现 脑梗塞的生化基础。

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.