The Mechanism of Cytoplasmic Incompatibility

细胞质不相容的机制

基本信息

批准号：
10322407
负责人：
SETH R BORDENSTEIN
金额：
$ 39.63万
依托单位：
VANDERBILT UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2020
资助国家：
美国
起止时间：
2020-01-01 至 2022-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10322407
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

项目摘要

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，是一种有前景、具有成本效益的遏制寨卡病毒的工具。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。其次，沃尔巴克氏体通过一个称为“自私”的过程来改变精子和卵子细胞质不相容性（CI）可以驱使细菌进入宿主群体。 CI 表达为胚胎受感染的雄性和未受感染的雌性之间的杂交具有致死率，但这种致死率在杂交中得到了挽救感染的男性和感染的女性之间存在沃尔巴克氏体的传播性别。因此，CI 是在实地试验中部署，以抑制蚊子种群规模或用感染者对虫媒病毒感染有抵抗力。我们最近公开了 CI 的遗传模型，其中两个基因（cifA 和 cifB）的表达在睾丸中表达时会导致胚胎致死，并且相同的基因之一（cifA）在卵巢中表达时可以挽救致死性。在胚胎致死之前，一些出现受精后缺陷，包括父本核膜延迟破裂、有丝分裂停滞和染色质桥接。由于沃尔巴克氏体在精子发生过程中从精子中剥离，因此 cifA 引起的缺陷 cifB 可能是由于受精前精子完整性受损所致。尽管经历了四十年媒介控制工作的深入研究和当前应用，围绕这些预受精的细节损伤仍然是一个中心谜。本研究的总体假设是 cifA 和 cifB 编码改变精子完整性从而导致 CI 的蛋白质。在目标 1 中，我们将使用细胞化学、酶学和转基因测定，以确定精子修饰的类型、强度和遗传基础世界蚊子计划在现场试验中释放了来自 wMel Wolbachia 的 Cif 蛋白。在目标 2 中，我们将研究精子发生和储存过程中 Cif 蛋白的定位模式。我们还将确定 Cif 蛋白与宿主或沃尔巴克氏体蛋白之间的重要相互作用。基因敲除和转基因实验将探讨蛋白质-蛋白质相互作用对于 CI 表达的必要性。终于瞄准了 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注射到未感染的宿主体内以重现 CI 和救援。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。研究尚未得出结果影响配子的自然 CI 缺陷的机制突破，以及部署的兴趣日益浓厚沃尔巴克氏体要遏制虫媒病毒传播，就必须紧急了解导致该病毒传播的事件 CI驱动系统。如果成功，这项研究将从根本上推进 CI 修饰的研究并提供信息沃尔巴克氏体作为控制全球节肢动物的天然工具，其持续的功效和交付。