The Mechanism of Cytoplasmic Incompatibility

细胞质不相容的机制

• 批准号: 9885060
• 负责人: SETH R BORDENSTEIN
• 金额: $ 38.63万
• 依托单位: VANDERBILT UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-01-01 至 2024-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9885060
• 关键词: Antibodies; Arbovirus Infections; Arboviruses; Arthropods; Bacteria; Bacteriophages; Biological Assay; Cells; Cessation of life; Chromatin; Communities; Culex pipiens; Culicidae; DNA; Defect; Dengue; Dengue Virus; Deposition; Deubiquitination; Development; Drosophila melanogaster; Embryo; Embryonic Development; Event; Female; Fertilization; Filtration; Frequencies; Genes; Genetic; Genetic Models; Genotype; Germ Cells; Immunoprecipitation; Impairment; Individual; Inherited; Injections; Knock-out; Lead; Link; Mass Spectrum Analysis; Mitotic; Modification; Monitor; Mosquito-borne infectious disease; Names; Nuclear Envelope; Ovary; Partner in relationship; Pathogenicity; Pattern; Phenotype; Pilot Projects; Population; Population Programs; Population Replacements; Population Sizes; Prevalence; Process; Property; Protamines; Proteins; RNA Viruses; Reproduction; Research; Research Project Grants; Resistance; Scholarship; Seminal Vesicles; Spermatogenesis; System; Testis; Toxin; Transgenes; Transgenic Organisms; Travel; Vectorial capacity; Wolbachia; ZIKA; Zika Virus; base; cost effective; egg; experimental study; fitness; gene product; interest; knock-down; male; novel; pandemic disease; particle; programs; protein complex; protein protein interaction; reproductive; sex; sperm cell; tool; transmission process; vector control; wasting

Project Summary: Wolbachia are a genus of endosymbiotic bacteria that comprise a promising, cost-effective tool to curb Zika and dengue arboviral transmission based on two key facets. First, Wolbachia block pathogenic RNA viruses by inhibiting their replication in arthropods. Second, Wolbachia selfishly alter sperm and egg via a process termed cytoplasmic incompatibility (CI) that can drive the bacteria into host populations. CI is expressed as embryonic lethality in crosses between infected males and uninfected females, but this lethality is rescued in crosses between infected males and infected females, which are the transmitting sex of Wolbachia. Consequently, CI is deployed in field trials to either suppress mosquito population sizes or replace uninfected populations with infected individuals resistant to arboviral infection. We recently exposed a genetic model of CI wherein expression of two genes (cifA and cifB) causes embryonic lethality when expressed in testes, and expression of one of the same genes (cifA) rescues lethality when expressed in ovaries. Prior to embryonic lethality, several post-fertilization defects arise including delayed breakdown of the paternal nuclear envelope, mitotic arrest, and chromatin bridging. As Wolbachia are stripped from sperm during spermatogenesis, the defects caused by cifA and cifB may be due to uncharacterized pre-fertilization impairments to sperm integrity. Despite four decades of intense research and current applications to vector control efforts, the details surrounding these pre-fertilization impairments remain a central enigma. The overarching hypothesis of the proposed research is cifA and cifB encode proteins that alter sperm integrity to cause CI. In Aim 1, we will use cytochemical, enzymatic, and transgenic assays to determine the types, strength, and genetic bases of sperm modifications imposed by the Cif proteins from wMel Wolbachia released in field trials by the World Mosquito Program. In Aim 2, we will investigate localization patterns of the Cif proteins during spermatogenesis and storage. We will also identify important interactions between the Cif proteins and either host or Wolbachia proteins. Knockout and transgenic experiments will interrogate the necessity of the protein-protein interactions for expression of CI. Finally in Aim 3, we will evaluate if the natural CI proteins or protein complex can be experimentally isolated and successfully injected into uninfected hosts to recapitulate CI and rescue. In these experiments, we will evaluate a novel association between the Cif proteins and bacteriophage WO particles from Wolbachia. Studies have yet to yield a mechanistic breakthrough for the natural CI defects afflicting gametes, and the rising interest in deploying Wolbachia to curb arbovirus transmission necessitates an urgent understanding of the events underpinning the CI drive system. If successful, this research will fundamentally advance studies of CI modifications and inform Wolbachia's ongoing efficacy and delivery as a natural tool to control arthropods worldwide.

项目概要： 沃尔巴克氏体是一种内共生细菌，是遏制寨卡病毒的一种有前途的、具有成本效益的工具， 登革热虫媒病毒传播基于两个关键方面。首先，沃尔巴克氏体通过以下方式阻断致病性RNA病毒： 抑制它们在节肢动物中的复制。第二，沃尔巴克氏体通过一种称为 细胞质不相容性（CI），可驱使细菌进入宿主种群。CI表达为胚胎 在受感染的雄性和未受感染的雌性之间的杂交中， 感染的男性和女性之间，这是沃尔巴克氏体的传播性别。因此，CI是 部署在现场试验中，以抑制蚊子种群规模或用 对虫媒病毒感染有抵抗力的受感染个体。我们最近发现了一个CI的遗传模型， 两个基因（cifA和cifB）的表达在睾丸中表达时导致胚胎死亡， 其中一个相同的基因（cifA）在卵巢中表达时挽救了致死性。在胚胎致死之前， 受精后出现的缺陷包括父本核膜延迟破裂、有丝分裂停滞， 染色质桥接当沃尔巴克氏体在精子发生过程中从精子中剥离时，cifA引起的缺陷 而cifB可能是由于受精前精子完整性的未表征损害造成的。尽管四十年来， 密集的研究和目前的应用，以病媒控制的努力，围绕这些细节前受精 损伤仍然是一个核心谜团。本研究的主要假设是cifA和cifB 编码改变精子完整性导致CI的蛋白质。在目标1中，我们将使用细胞化学，酶， 转基因试验，以确定类型，强度和遗传基础的精子修改强加的 来自wMel Wolbachia的Cif蛋白在世界苔藓计划的田间试验中释放。在目标2中，我们将 研究Cif蛋白在精子发生和储存过程中的定位模式。我们还将确定 Cif蛋白与宿主或Wolbachia蛋白之间的重要相互作用。敲除和转基因 实验将询问蛋白质-蛋白质相互作用对于CI表达的必要性。最后，在Aim 3.我们将评估天然CI蛋白或蛋白复合物是否可以通过实验分离并成功地 注射到未感染的宿主中以重现CI和拯救。在这些实验中，我们将评估一部小说 Cif蛋白与来自沃尔巴克氏体的噬菌体WO颗粒之间的关联。研究还没有得出结论 这是对影响配子的自然CI缺陷的机械突破， 沃尔巴克氏体抑制虫媒病毒传播需要紧急了解事件的基础， CI驱动系统。如果成功的话，这项研究将从根本上推进CI修改的研究， 沃尔巴克氏体作为控制全球节肢动物的天然工具的持续功效和交付。