Genetic Analysis of Olfaction

描述(申请人提供)：这项研究的长期目标是阐明果蝇雄性特有的挥发性信息素11-顺式痘烯基乙酸酯(CVA)敏感的分子机制。这项工作意义重大，因为了解果蝇中信息素的信号转导将转化为控制昆虫繁殖的新方法，这些昆虫传播人类疾病并破坏作物。在上一个资金周期中，我们在阐明CVA认知的机制方面取得了重大进展。我们发现了一种独特的信号范式，其中信息素敏感神经元的激活是通过细胞外气味结合蛋白LOSH的构象激活来介导的。我们已经鉴定了几种蛋白质，这些蛋白质是由激活的LUSH触发的神经受体复合体的组成部分，包括果蝇气味受体家族的成员Or67d，以及果蝇CD36的同源物SNMP，CD36是一种膜蛋白，与人类的动脉粥样硬化和血脂异常有关。我们还在正向遗传筛选中发现了正常信息素检测所必需的四种新基因产物。在下一个资金周期，我们准备通过探索这些因素如何调节CVA敏感性而取得快速进展。我们提出了一种包括遗传学、电生理学、生物化学、细胞和结构生物学的多学科方法。第一个目标是进一步确定在信息素检测级联中，激活的LUSH与T1树突上的哪些物质相互作用。我们还将启动实验，以了解Or67d中的单个氨基酸突变是如何消除信号的。第二个目标是确定我们为LUSH发现的构象激活机制是否对其他OBP保守。第三个目的是确定四个新的CVA敏感性因子的作用，它们是正向遗传筛查中发现的ODD、Vans、VainsB和VainsE。目标4是确定CVA信号检测定位到第二条染色体所需的组件，使我们更接近识别对CVA敏感性至关重要的完整基因产物的总体目标。这些研究的完成将促进我们对昆虫中挥发性信息素信号的理解，将确定操纵昆虫行为的新靶点，并将指导未来在更复杂的动物模型系统中关于信息素信号的研究。 与公共卫生相关：昆虫携带人类疾病，每年导致数百万人死亡；仅疟疾一项每年就造成100多万人死亡。昆虫还影响农业，每年摧毁价值数十亿美元的农作物。许多昆虫的行为，包括交配，都是由对信息素的感知引发的。在分子水平上了解信息素是如何被检测到的，将为操纵信息素通信提供新的靶点，长期目标是阻止交配信号和病原昆虫中其他信息素引导的行为。我们已经确定了果蝇挥发性信息素检测所必需的几个基因，并将阐明这些因素在信息素检测中的作用。

DESCRIPTION (provided by applicant): The broad long-term objective of this research is to elucidate the molecular mechanisms underlying sensitivity to the Drosophila male-specific volatile pheromone, 11-cis vaccenyl acetate (cVA). This work is significant because understanding pheromone signal transduction in Drosophila will translate into new methods to control reproduction in insects that transmit human diseases and destroy crops. In the last funding cycle, we made significant progress toward elucidating the mechanisms underlying cVA perception. We discovered a unique signaling paradigm in which activation of pheromone-sensitive neurons is mediated by conformational activation of the extracellular odorant binding protein, LUSH. We have identified several of the proteins that are components of the neuronal receptor complex triggered by activated LUSH, including Or67d, a member of the Drosophila odorant receptor family, and SNMP, a Drosophila homolog of CD36, a membrane protein implicated in atherosclerosis and dyslipidemia in humans. We also found four new gene products essential for normal pheromone detection in a forward genetic screen. In the next funding cycle, we are poised to make rapid progress by exploring how these factors mediate cVA sensitivity. We propose a multidisciplinary approach that includes genetics, electrophysiology, biochemistry, cell and structural biology. The first aim is to further define what activated LUSH interacts with on the T1 dendrites in the pheromone detection cascade. We will also initiate experiments to understand how a single amino-acid mutation in Or67d eliminates signaling. The second aim is to establish if the conformational activation mechanism we have uncovered for LUSH is conserved for other OBPs. The third aim is to define the roles of four new cVA sensitivity factors, odd, vans, vainsB and vainsE identified in the forward genetic screen. Aim 4 is to identify the components required for cVA signal detection mapping to the second chromosome, bringing us closer to our overall goal of identifying the complete set of gene products important for cVA sensitivity. The completion of the studies outlined here will advance our understanding of volatile pheromone signaling in insects, will identify new targets to manipulate insect behavior, and will guide future studies on pheromone signaling in more complex animal model systems. PUBLIC HEALTH RELEVANCE: Insects carry human diseases that kill millions of people every year; malaria alone accounts for over one million deaths annually. Insects also impact agriculture, destroying billions of dollars worth of crops annually. Many insect behaviors, including mating, are triggered by perception of pheromones. Understanding how pheromones are detected at the molecular level will provide new targets to manipulate pheromone communication, with the long-term goal of blocking mating signals and other pheromone-guided behaviors in pathogenic insects. We have identified several genes essential for volatile pheromone detection in Drosophila and will elucidate the roles of these factors in pheromone detection.