Olfactory receptors and neurons regulating odor-guided behaviors in mosquitoes

项目摘要/摘要 冈比亚按蚊，作为导致疟疾的疟原虫的昆虫媒介， 对去年45万人的死亡负有责任。幸运的是，蚊子有一个弱点 我们的研究旨在利用。蚊子利用它们的嗅觉来寻找大多数人类寄主 行为。这表明，针对蚊子的嗅觉可能会导致有效的措施， 防止咬伤和疾病传播。事实上，空间驱避剂是一种挥发性气味，可以有效地 扰乱寻找宿主的行为，防止蚊子靠近。它们被广泛应用于 发达国家作为个人保护措施，但由于成本高，全球采用有限， 不想要的副作用(如皮肤刺激)，或需要使用高浓度才能保持 有效。识别新的、更易处理的驱蚊剂的一个主要限制是缺乏 了解空间驱避剂如何通过影响蚊子的嗅觉来促进排斥力。 这主要是由于将驱虫剂和其他气味物质与 嗅觉神经元的各种功能。我们将QF2/QAS遗传二元系引入到 按蚊克服了以前的技术障碍，现在使我们能够直接可视化 蚊子嗅觉神经元对驱蚊剂和人体气味的反应。使用 钙成像、单感受器电生理记录和rna-seq的联合应用 利用我们已建立的和新的基因技术，我们将检验(1)空间蚊子的假设 驱避剂通过掩蔽、激活或扰乱嗅觉神经元的活动来发挥作用。我们会 观察冈比亚按蚊存活时嗅觉神经元的活动模式 在有无人类气味的情况下，用20种常用驱蚊剂进行刺激。 此外，我们还将鉴定嗅觉神经元表达的气味受体。 对每种驱避剂作出反应的活动模式。使用遗传方法的组合(目标是 调节目标嗅觉神经元的功能)和行为分析，我们将测试 空间排斥剂通过改变嗅觉系统促进排斥性行为的假说 发信号。我们将通过实验确定哪些嗅觉神经元和哪种类型的嗅觉 神经元活动的改变对于驱动排斥行为是必要的和/或充分的。这个 拟议的研究具有重要意义，因为我们将获得关于蚊子如何 驱蚊剂的目标是蚊子的嗅觉，并使基于生物学的原理得以发展 确定更便宜、更安全、更有效地在全球范围内使用的新驱避剂的战略 以防止疾病的传播。

Project Abstract/Summary Anopheles gambiae mosquitoes, as the insect vector for the Plasmodium parasite that causes malaria, were responsible for the deaths of >450,000 people last year. Fortunately, mosquitoes have a weakness that our research aims to exploit. Mosquitoes use their sense of smell for most human host-seeking behaviors. This suggests that targeting a mosquito's sense of smell could lead to effective measures that prevent bites and the spread of diseases. Indeed, spatial repellents are volatile odorants that effectively disrupt host-seeking behaviors and keep mosquitoes from approaching. They have widespread use in developed nations as personal protective measures, but global adoption is limited due to high costs, unwanted side-effects (such as skin irritation), or the need to use high-concentrations to remain effective. A major limitation to the identification of new, more tractable, repellents is a lack of understanding of how spatial repellents promote repulsion by impacting the mosquito's sense of smell. This is primarily due to challenging technical hurdles needed to link repellent and other odorants to a variety of olfactory neuron functions. Our introduction of the QF2/QUAS genetic binary system into Anopheles mosquitoes overcomes previous technical barriers, and now enables us to directly visualize the response of olfactory neurons, in living mosquitoes, to repellents and human body odors. Using a combination of calcium imaging, single sensillum electrophysiological recordings, and RNA-seq along with our established and novel genetic techniques, we will test the hypothesis that (1) spatial mosquito repellents function by masking, activating, or scrambling the activity of olfactory neurons. We will examine the activity patterns of olfactory neurons in living Anopheles gambiae mosquitoes when stimulated by 20 commonly used mosquito repellents in the presence and absence of human odorants. In addition, we will identify the odorant receptors expressed by olfactory neurons exhibiting altered activity patterns in response to each repellent. Using a combination of genetic approaches (aimed at modulating the function of targeted olfactory neurons) and behavioral assays, we will test the hypothesis that (2) spatial repellents promote repellent behaviors by altering olfactory system signaling. We will experimentally determine which olfactory neurons and what types of olfactory neuron activity changes are either necessary and/or sufficient to drive repellent behaviors. The proposed studies are significant because we will gain new mechanistic insights into how mosquito repellents target the mosquito's sense of smell and enable the development of rationale biology-based strategies to identify new repellents that are cheaper, safer, and more effective for use on a global scale to prevent the spread of disease.