The Mechanism of Cytoplasmic Incompatibility

细胞质不相容的机制

• 批准号: 10078245
• 负责人: SETH R BORDENSTEIN
• 金额: $ 39.56万
• 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/10078245
• 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; Sexual Reproduction; 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.

项目摘要： Wolbachia是内共生细菌的属，它构成了一种有希望的，具有成本效益的工具，用于遏制Zika和 基于两个关键方面的登革热弧病毒变速器。首先，Wolbachia通过 抑制其在节肢动物中的复制。其次，沃尔巴奇（Wolbachia）通过称为过程自私地改变精子和鸡蛋 可以将细菌驱动到宿主种群的细胞质不相容性（CI）。 CI表示为胚胎 被感染的男性和未感染的女性之间的十字架的致死性，但这种致死性是在十字架中拯救的 在被感染的男性和受感染的女性之间，这是沃尔巴奇的传播性别。因此，CI是 部署在现场试验中以抑制蚊子人口规模，或用 受感染的个体对灰臂感染有抵抗力。我们最近暴露了CI的遗传模型，其中 两种基因（CIFA和CIFB）的表达在睾丸中表达时会引起胚胎致死性，并表达 相同的基因（CIFA）之一在卵巢中表达时挽救了致死性。在胚胎致死性之前，有几个 产后缺陷出现，包括延迟的父亲核包络，有丝分裂逮捕和 染色质桥接。由于在精子发生过程中，由于沃尔巴基亚从精子中剥离，因此CIFA引起的缺陷 CIFB可能是由于精子完整性的未表征的预处理损害所致。尽管有四十年 激烈的研究和当前在矢量控制工作中的应用，这些涉及这些预先利用的细节 损害仍然是中心的谜。拟议的研究的总体假设是CIFA和CIFB 编码改变精子完整性以引起CI的蛋白质。在AIM 1中，我们将使用细胞化学，酶促和 从 来自WMEL Wolbachia的CIF蛋白在世界蚊子计划中发布的现场试验中发布。在AIM 2中，我们将 在精子发生和储存过程中研究CIF蛋白的定位模式。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 - 蛋白质相互作用以表达CI的必要性。最后是目标 3，我们将评估天然CI蛋白或蛋白质复合物是否可以实验分离并成功地分离 注射到未感染的宿主中，以概括CI和救援。在这些实验中，我们将评估一个小说 CIF蛋白与来自沃尔巴奇的噬菌体WO颗粒之间的关联。研究尚未产生 自然CI缺陷的机械突破使痛苦的配子以及对部署的兴趣不断增加 Wolbachia要遏制Arbovirus的传播，必须紧急理解所支撑的事件 CI驱动系统。如果成功，这项研究将从根本上提高CI修改的研究并告知 沃尔巴奇（Wolbachia）的持续疗效和传递是控制全球节肢动物的自然工具。