The olfactory basis of locating nectar sugar sources in Aedes aegypti mosquitoes

埃及伊蚊定位花蜜糖源的嗅觉基础

• 批准号: 10802906
• 负责人: Omar Sultan Akbari
• 金额: $ 5.22万
• 依托单位: UNIVERSITY OF WASHINGTON
• 依托单位国家: 美国
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-03-05 至 2026-02-28
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10802906
• 关键词: Acids; Adult; Aedes; Afferent Neurons; Arboviruses; Behavior; Behavioral; Behavioral Assay; Biochemical; Bite; Blood; Brain; Calcium; Chemicals; Chemoreceptors; Communication; Culicidae; Data; Development; Discrimination; Disease; Environmental Wind; Feeding behaviors; Female; Flowers; Flying body movement; Fruit; Gene Targeting; Genes; Goals; Housekeeping Gene; Human; Human Microbiome; Image; Immune response; Insect Vectors; Insecta; Insecticides; Intervention; Knock-out; Literature; Lobe; Longevity; Mass Fragmentography; Mediating; Methods; Microbe; Modeling; Mosquito Control; Nutrient; Odorant Receptors; Odors; Olfactory Pathways; Orphan; Pathway interactions; Persons; Physiological Processes; Phytochemical; Plants; Play; Population; Process; Reproduction; Resources; Role; Sensory; Shapes; Signal Transduction; Skin; Smell Perception; Source; System; Testing; Time; Transgenic Organisms; Variant; Vectorial capacity; Work; analytical method; base; comparative; experimental study; feeding; field study; genetic approach; insight; male; microbial; microbiome; mutant; neural; receptor; response; sensory mechanism; skin microbiome; sugar; tool

The objective of the proposed R01 project is to build on our recent findings that attractive odors from sources of nectar activate conserved olfactory channels in mosquitoes, and the odorant ratios within the scent, along with the inhibition in the antennal lobe (AL), are critical for Aedes aegypti behavior. Feeding on fruits and flowers is a vital behavior for mosquitoes, and mosquito attraction to these sources of nectar is mediated by the ratio of key odorants in the bouquet. Bait-and-kill traps that use fruit syrups have effectively controlled local mosquito populations, but variation in the fruit odor can strongly impact its attractiveness. We still have not identified the odor constituents and ratios that are attractive in the nectar odors – enabling the development of synthetic lures –, nor how this information is detected and processed by the mosquito's olfactory system. Nectar-feeding by female mosquitoes increases their life-span and decreases the gonotrophic cycle, thereby increasing their vectorial capacity, and for adult males, it is the only source of nutrients. Our recent work allowed us to identify the odor constituents that mediate nectar-feeding behaviors in Ae. aegypti and understand how the odor is processed in the brain. Now in this application, we propose to use a combination of behavioral assays, chemical methods combined with calcium imaging in tethered flying mosquitoes, and genetic approaches to study the olfactory basis of nectar-seeking behaviors. Aim 1 will allow us to identify attractive odorants in the scents of diverse plant nectar sources and use heterologous expression systems to de-orphan the cognate odorant receptors (Ors). We also take advantage of the Q-system for genetically characterizing three Ors (Or15, Or49, and Or2) that are essential for representing the proper ratios in nectar odors. In Aim 2, we leverage our existing and new GCaMP expression lines to examine how the ratios of these key odorants are processed in the AL, and how GABAergic inhibition shapes these responses. In Aim 3, we will use our identified odor lures, and artificial lures that vary in their natural ratios of key odorants, to determine their efficacy in bait-and-kill systems. Together, these experiments will test the working hypothesis that nectar odors and their specific odorant ratios activate conserved olfactory channels to be processed similarly by AL circuits to mediate feeding behaviors. While there has been an extensive study of mosquito attraction to blood hosts, we know comparatively less about nectar feeding. Our experiments will identify new odors that can be immediately deployed as attractant lures. Additionally, GABAergic systems are involved in diverse physiological processes in insect vectors, including olfaction, immune response, and arbovirus replication, as well as being potent targets for insecticides. Generating mutants that target the mosquito's olfactory responses or GABAergic pathways could provide additional insight into these diverse processes. Sugar feeding plays an essential role in the vectorial capacity of mosquitoes and the spread of diseases that afflict over a billion people annually. Therefore, unraveling the neural bases of nectar-feeding will enable new gene-targets and tools for their control.

拟议的 R01 项目的目标是建立在我们最近的发现之上，即来自来源的有吸引力的气味 花蜜激活蚊子保守的嗅觉通道，以及气味中的气味比例，以及 触角叶 (AL) 的抑制对于埃及伊蚊以水果和花朵为食的行为至关重要。 蚊子的重要行为，蚊子对这些花蜜源的吸引力是由 花束中的主要气味剂使用水果糖浆制成的诱饵和灭杀器有效地控制了当地的蚊子。 人群，但水果气味的变化会强烈影响其吸引力。 花蜜气味中有吸引力的气味成分和比例——促进合成诱饵的开发 –，也没有蚊子的嗅觉系统如何检测和处理这些信息。 雌性蚊子的花蜜喂养延长了它们的寿命并减少了生殖周期，从而 增加它们的矢量能力，对于成年男性来说，这是我们最近的工作允许的唯一营养来源。 我们可以识别介导埃及伊蚊吸食花蜜行为的气味成分，并了解它们是如何产生的。 现在，在这个应用中，我们建议结合使用行为分析， 化学方法与系留飞蚊的钙成像相结合，以及遗传方法 研究寻找花蜜行为的嗅觉基础将使我们能够识别出有吸引力的气味。 不同植物花蜜来源的气味，并使用异源表达系统来消除同源 我们还利用 Q 系统对三个 Or（Or15、 Or49 和 Or2）对于代表花蜜气味的适当比例至关重要。在目标 2 中，我们利用我们的方法。 现有的和新的 GCaMP 表达线，以检查这些关键气味剂的比例是如何在 AL，以及 GABA 能抑制如何影响这些反应 在目标 3 中，我们将使用我们确定的气味诱饵，以及 人工诱饵的主要气味物质的自然比例各不相同，以确定其在诱饵和杀灭系统中的功效。 这些实验将共同检验花蜜气味及其特定气味比率的工作假设 激活保守的嗅觉通道，并由 AL 电路进行类似处理，以介导进食行为。 虽然已经对蚊子对血液宿主的吸引力进行了广泛的研究，但我们了解的相对较少 我们的实验将确定可以立即用作引诱剂的新气味。 此外，GABA能系统参与昆虫媒介的多种生理过程， 包括嗅觉、免疫反应和虫媒病毒复制，也是杀虫剂的有效目标。 生成针对蚊子嗅觉反应或 GABA 能途径的突变体可以提供 对这些不同过程的进一步了解在载体能力中起着至关重要的作用。 蚊子和疾病的传播每年困扰着超过十亿人。 花蜜喂养的神经基础将为它们的控制提供新的基因目标和工具。