Analysis of the functions of axon guidance genes during vector mosquito developme

描述(申请人提供)：蚊媒传染病是对人类日益增长的全球威胁。食血蚊子传播了世界上许多最致命的疾病。这类疾病在发展中国家死灰复燃，也正在成为发达国家疫情暴发的明显威胁。许多因素导致目前无法预防或控制这些疾病，包括疫苗开发进展缓慢，蚊子种群出现抗药性，寄生虫种群出现抗药性，许多发展中国家普遍缺乏对蚊子控制项目的支持，以及全球旅行增加。蚊子基因组计划激发了人们对通过基因操作媒介昆虫控制节肢动物传播疾病的潜力的越来越大的兴趣。特别令人感兴趣的目标包括调节发育的基因。对蚊子神经系统发育调控基因的分析将有助于更好地理解蚊子寄主位置的关键方面--运动功能、感觉加工和行为的发育基础。此外，对蚊子唾液腺的发育进行分析，这对感染的传播至关重要，可能会导致创造出更多的控制蚊子的方法。然而，人们对蚊子发育过程中这些或其他组织的遗传调控知之甚少。近年来，进化发育生物学家应用黑腹果蝇的发育遗传学知识，更好地了解其他节肢动物的发育。对果蝇轴突引导分子的分析表明，这些蛋白质在果蝇发育过程中调节着许多发育过程，包括胚胎轴突引导、嗅觉神经引导和唾液腺发育。初步数据支持这一假设，即这些基因的作用在蚊子中是保守的。因此，分析蚊子轴突引导基因的功能可以促进对蚊子神经系统和唾液腺发育的更好了解。本研究的具体目的是研究几个轴突引导基因，包括Netrin及其DCC受体，以及Semaphorin1a及其PlexinA受体在蚊子发育过程中的功能。这些研究将包括黄热病和登革热病毒媒介埃及伊蚊，以及疟疾媒介冈比亚按蚊。将被用来检验轴突引导基因功能在蚊子中保守的假设的方法包括基因和蛋白质表达分析，以及遗传抑制策略(RNA抑制/吗啡)。详细分析蚊子发育调控基因的功能并选择性地抑制这些基因是实现本研究计划长期目标的必要步骤，该研究计划旨在选择性地针对蚊子的发育基因，以努力控制蚊媒传染病。与公共卫生相关：尽管人们对控制媒介蚊子发育的基因知之甚少，但对蚊子发育的基因分析可以揭示灭蚊药物的新靶点。本研究旨在通过基因表达分析和RNA抑制研究，分析登革热和黄热病病毒载体埃及伊蚊和疟疾媒介冈比亚按蚊中几个发育调控基因的功能。这些研究的结果可能也适用于其他媒介蚊子。

DESCRIPTION (provided by applicant): Mosquito-borne infectious diseases are an increasing global threat to humans. Blood-feeding mosquitoes transmit many of the world's deadliest diseases. Such diseases have resurged in developing countries and are also emerging as clear threats for epidemic outbreaks in developed countries. Numerous factors contribute to the current inability to prevent or control these diseases, including poor progress in vaccine development, the appearance of insecticide resistance in mosquito populations, the emergence of drug resistance in parasite populations, a general lack of support in many developing countries for mosquito control programs, and increased global travel. The mosquito genome projects have stimulated increased interest in the potential for arthropod-borne disease control by genetic manipulation of vector insects. Targets of particular interest include genes that regulate development. Analysis of genes that regulate mosquito nervous system development will lead to a better understanding of the developmental basis of motor function, sensory processing, and behavior, key aspects of mosquito host location. Furthermore, analysis of the development of mosquito salivary glands, which are essential for the spread of infection, could lead to creation of additional means of controlling mosquitoes. However, extremely little is known about the genetic regulation of these or other tissues during mosquito development. In recent years, evolutionary developmental biologists have applied knowledge of developmental genetics in Drosophila melanogaster, a genetically tractable model organism, to better understand development of other arthropods. Analysis of axon guidance molecules such as Netrins and Semaphorins in Drosophila indicate that these proteins regulate numerous developmental processes during fly development, including embryonic axon guidance, olfactory neural guidance, and salivary gland development. Preliminary data support the hypothesis that the roles of these genes are conserved in mosquitoes. Analysis of the functions of axon guidance genes in mosquitoes could therefore promote a better understanding of mosquito nervous system and salivary gland development. The specific aims of this investigation are to characterize the function of several axon guidance genes, including Netrin and its DCC receptor, and Semaphorin1a and its PlexinA receptor during mosquito development. These studies will include the yellow and dengue fever virus vector Aedes aegypti, as well as the malaria vector Anopheles gambiae. Methods that will be employed to test the hypothesis that axon guidance gene function is conserved in mosquitoes include gene and protein expression assays, as well as genetic knock-down strategies (RNA inhibition/morpholinos). Detailed analysis of the function of developmental regulatory genes and selective inhibition of such genes in mosquitoes is a requisite step toward attaining the long-term goals of this research program, which are to selectively target mosquito developmental genes in an effort to control mosquito-borne infectious diseases. PUBLIC HEALTH RELEVANCE: Although very little is known about the genes that regulate vector mosquito development, genetic analysis of mosquito development can reveal new targets for mosquito-control agents. The proposed research aims to analyze the function of several developmental regulatory genes in the dengue and yellow fever virus vector Aedes aegypti and the malaria vector Anopheles gambiae through analysis of gene expression and RNA inhibition studies. Results obtained in these studies will likely be applicable to other vector mosquitoes.