Neuropeptide Regulation of Mosquito Host-Seeking Behavior

描述(申请人提供)：神经肽是从蠕虫到人类神经系统功能的重要调节器。由专门的神经分泌细胞产生，它们被控制释放到局部大脑回路和循环系统，对化学感觉、摄食、昼夜节律、睡眠、社会行为和一般生理动态平衡有深远的影响。在埃及伊蚊中，神经肽参与了对寄主吸引的周期性行为抑制，这种行为在雌性吸血后持续三天。虽然喂食糖就足以生存，但一旦雌性蚊子达到生殖成熟，它们就需要血液喂养才能产卵。只有当雌性需要血液蛋白来产卵时，才会表现出对人体寄主线索的吸引力，包括体温、二氧化碳、体味和皮肤上的味道线索。在一顿血餐后的大约72小时内，雌性对人类的吸引力被抑制。在大约一个月的成年生命中，这个周期重复多达10次。传染病在人类中的传播是这种血液循环的副产品，因此阐明宿主抑制的机制具有很大的健康意义。这项研究的长期目标是全面了解蚊子神经肽和神经肽受体的功能，并确定血餐后强烈抑制寄主行为的机制。该提案有三个相互关联的特定目标：(1)注释埃及伊蚊的神经肽和神经肽受体基因，并定义配体与受体的相互作用。(2)确定调节血餐后寄主寻找抑制的神经肽信号通路。(3)研制用于研究蚊子神经肽信号传导的遗传工具包。这项工作是创新的，因为它使用了高通量的384孔细胞筛选和遗传编码的钙指示剂来使神经肽受体去变形；药理学和神经遗传学工具来探索血餐后宿主抑制的潜在机制；以及优化的CRISPR/Cas9基因组编辑来产生大量突变菌株，每个突变菌株都缺乏给定的神经肽或神经肽受体。该项目将对这种重要的疾病媒介昆虫中神经肽受体的配体和生物学功能产生重要的见解，并将为调节蚊子寻找宿主的行为提供新的工具。该项目开发的菌株将成为研究神经肽信号转导的生理功能的有价值的社区资源。

DESCRIPTION (provided by applicant): Neuropeptides are important modulators of nervous system function from worms to humans. Produced by specialized neurosecretory cells, their controlled release into local brain circuits and the circulatory system has profound effects on chemosensation, feeding, circadian rhythms, sleep, social behavior, and general physiological homeostasis. In Aedes aegypti mosquitoes, neuropeptides have been implicated in the cyclical behavioral suppression of host attraction that lasts for three days after the female has taken a blood-meal. Although sugar- feeding is sufficient for survival, once female mosquitoes reach reproductive maturity, they require a blood-meal to develop eggs. Attraction to human host cues, including body heat, carbon dioxide, body odor, and taste cues on skin, is only expressed when the female needs blood protein for egg production. For approximately 72 hours after a blood-meal, female attraction to humans is suppressed. This cycle repeats up to 10 times for the approximately one month adult life-span. The spreading of infectious diseases among humans is a by- product of this blood-feeding cycle, so elucidating the mechanisms of host suppression has great health relevance. The broad, long-term objectives of this research are to gain a comprehensive understanding of mosquito neuropeptide and neuropeptide receptor function and to define the mechanisms that mediate the strong suppression of host-seeking behavior after a blood-meal. The proposal has three interlocking specific aims: (1) Annotate neuropeptide and neuropeptide receptor genes in Aedes aegypti and define ligand-receptor interactions. (2) Identify neuropeptide signaling pathways that mediate host-seeking suppression after a blood-meal. (3) Develop a genetic tool-kit for studying neuropeptide signaling in the mosquito. The work is innovative because it uses high-throughput 384-well cell-based screening with a genetically-encoded calcium indicator to deorphanize neuropeptide receptors; pharmacological and neurogenetic tools to probe mechanisms underlying post blood-meal host-suppression; and optimized CRISPR/Cas9 genome-editing to generate a large collection of mutant strains, each lacking a given neuropeptide or neuropeptide receptor. The project will yield significant insights into the ligands and biological function of neuropeptide receptors in this important disease vector insect and will provide new tools to regulate mosquito host-seeking behavior. The strains developed under this project will be a valuable community resource for investigating the physiological functions of neuropeptide signaling.