Diapause in Culex Mosquitoes

描述（由申请人提供）：蚊媒疾病是大多数发展中国家的主要健康问题，并已成为发达国家流行病爆发的重大威胁。使这些问题恶化的是蚊子种群中杀虫剂耐药性的出现、寄生虫种群的耐药性、疫苗开发进展的延迟、蚊虫控制规划缺乏支持以及全球旅行的增加。库蚊群中的蚊子是淋巴丝状线虫寄生虫、班氏乌氏菌和几种虫媒病毒的主要载体。这包括最近在北美传入的西尼罗河病毒。该研究的长期目标是鉴定、分离和表征与滞育有关的遗传因素，滞育是一种强烈影响物种在库蚊复合体中地理分布和生存的性状。目前，对库蚊滞育的分子决定因素尚不清楚。这一应用的目的是基于与滞育表型相关的基因可以通过定位克隆技术鉴定和分离的一般假设。鉴定决定滞育的基因和对相关生化途径的详细了解可能有几种潜在的应用，包括：在种群更替后促进改变和疾病限制行为的转基因构建，靶向生物农药的开发，或鉴定破坏对病原体传播或生存至关重要的行为的生物学相关拮抗剂。该项目的具体目标是：1)确定含有决定滞育表型基因的基因组区域的精细图谱；2)确定决定滞育的候选基因；3)对决定滞育的候选基因进行功能分析。基因杂交的信息将被用来对付Cx。致倦库蚊基因组计划在离散的基因组区域内鉴定候选基因。候选基因将使用微阵列进行评估，随后进行实时定量PCR分析，以确认和扩展有希望基因的微阵列结果。阳性候选基因将使用RNA干扰介导的基因敲低或使用重组Sindbis转导病毒的基因过表达来检测其生物学相关性。然后将在代表Cx的自然种群中评估实验室实验的结果。库蚊属；quinquefasciatus。公共卫生相关性：库蚊群中的蚊子是人类淋巴丝虫病和几种虫媒病毒（包括西尼罗河病毒）的主要媒介。没有可用的疫苗，疾病预防在很大程度上依赖于避免与受感染的蚊子接触。该研究将为成年雌蚊在温带气候冬季的滞育生存能力提供有价值的新生物学信息。

DESCRIPTION (provided by applicant): Mosquito-borne diseases represent major health problems in most developing countries and have emerged as significant threats for epidemic outbreaks in developed countries. Exacerbating these problems are the emergence of insecticide resistance in mosquito populations, drug resistance among parasite populations, delayed progress in vaccine development, lack of support for mosquito control programs, and increased global travel. Mosquitoes in the Culex pipiens complex are primary vectors for the lymphatic filarioid nematode parasite, Wuchereria bancrofti and several arboviruses. This includes the recently introduced West Nile virus in North America. The long- term objectives of the proposed research are to identify, isolate and characterize genetic factors associated with diapause, a trait that strongly impacts the geographic distribution and survival of species within the Culex pipiens complex. At present, no knowledge exists on the molecular determinants of diapause in Culex. The objectives of this application are based on the general hypothesis that genes associated with the diapause phenotype can be identified and isolated by positional cloning techniques. Identification of genes determining diapause and the knowledge from the detailed understanding of the associated biochemical pathways could have several potential applications including: transgene constructs that promote altered and disease limiting behaviors following population replacement, development of targeted biopesticides, or identification of biologically relevant antagonists that disrupt behaviors critical to pathogen transmission or survival. The specific aims of the project are to: 1) fine-scale map genome regions identified as containing genes that determine the diapause phenotype, 2) identify candidate genes determining diapause, and 3) conduct functional analysis of candidate genes determining diapause. Information from genetic crosses will be leveraged against the Cx. quinquefasciatus genome project to identify candidate genes within discrete genome regions. Candidate genes will be evaluated using microarrays, followed by quantitative real time PCR assays to confirm and expand microarray results for promising genes. Positive candidate genes will be assayed for biological relevance using RNA interference mediated gene knockdowns or gene overexpression using recombinant Sindbis transducing viruses. Results from laboratory experiments will then be evaluated among natural populations representing Cx. pipiens s.s. and Cx. quinquefasciatus. PUBLIC HEALTH RELEVANCE: Mosquitoes in the Culex pipiens complex are primary vectors for human lymphatic filariasis and several arboviruses, including the West Nile virus. No vaccines are available and disease prevention is largely dependent on avoiding contact with infected mosquitoes. The proposed research will provide valuable new information on the biology of the mosquito relating to the ability of adult females to survive temperate climate winter in a diapause state.