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

描述（由申请人提供）：蚊媒传染病是对人类日益严重的全球威胁。吸血蚊子传播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流行病爆发的明显威胁。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，蚊子种群出现杀虫剂耐药性，寄生虫种群出现耐药性，许多发展中国家普遍缺乏对蚊子控制计划的支持，以及全球旅行增加。蚊子基因组计划激发了人们对通过对病媒昆虫进行基因操作来控制节肢动物传播疾病的潜力的兴趣。特别感兴趣的靶标包括调节发育的基因。对调节蚊子神经系统发育的基因进行分析，将有助于更好地了解运动功能、感觉处理和行为的发育基础，这些都是蚊子宿主定位的关键方面。此外，对蚊子唾液腺的发育进行分析，这对感染的传播是必不可少的，可能会导致创造更多的控制蚊子的手段。然而，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，进化发育生物学家已将发育遗传学的知识应用于遗传学上易于处理的模式生物黑腹果蝇，以更好地了解其他节肢动物的发育。对果蝇中轴突导向分子如Netrins和Semaphorins的分析表明，这些蛋白质在果蝇发育过程中调节许多发育过程，包括胚胎轴突导向、嗅觉神经导向和唾液腺发育。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，对蚊子轴突导向基因功能的研究有助于更好地了解蚊子神经系统和唾液腺的发育。本研究的具体目的是描述几个轴突导向基因在蚊子发育过程中的功能，包括Netrin及其DCC受体，Semaphorin 1a及其PlexinA受体。这些研究将包括黄热病和登革热病毒载体埃及伊蚊以及疟疾载体冈比亚按蚊。将用于测试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测定，以及遗传敲低策略（RNA抑制/吗啉代）。详细分析蚊子发育调节基因的功能并选择性抑制此类基因是实现该研究计划长期目标的必要一步，即选择性靶向蚊子发育基因，以控制蚊子传播的传染病。公共卫生相关性：虽然对调控媒介蚊子发育的基因知之甚少，但对蚊子发育的遗传分析可以揭示蚊子控制剂的新靶点。拟议的研究旨在通过基因表达分析和RNA抑制研究来分析登革热和黄热病病毒载体埃及伊蚊和疟疾载体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适用于其他病媒蚊子。

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.