Sensory Physiology and Genomics of Olfaction in Drosophila Mojavensis

感知环境中的化学物质是许多动物从周围环境获取信息的主要方式。动物对这些信号的行为反应可能会影响它们的繁殖成功。这方面的一个例子是昆虫对它们赖以为生的不同植物的偏好，这是基于这些植物释放出的化合物。具体来说，它们通过嗅觉感知化学信号的能力的变化而对化学信号的偏好发生了变化，这可能导致种群和物种形成之间的分歧。这项研究将在不同地理范围的化学线索差异的背景下，研究单一物种嗅觉系统的进化。这些知识对于更广泛地理解遗传和神经变异如何导致行为的根本差异是至关重要的。因此，拟议工作的结果将记录物种出现的机制。它还将对应用农业产生广泛的影响。许多食草昆虫利用它们的嗅觉来寻找食物和配偶，这对农业生产力造成了不利影响。总之，除了促进对嗅觉的理解外，本研究还将为理解行为差异和生态物种形成的机制提供模型。此外，它的综合性质使它非常适合训练学生，因为它使用了行为、分子遗传学和神经生理学的方法。拓展活动将包括让高中生通过动手体验式学习来进行研究，重点介绍拟议研究的结果，更广泛地说，是感官生物学和进化的概念。对物种形成的理想理解包括在物种形成完成之前对其过程的考察。mojavensis果蝇的四个地理位置不同的种群目前利用四种不同的仙人掌物种，这些仙人掌释放出挥发性化合物的特定组合，这些化合物是植物识别的主要线索。本研究的目的是确定嗅觉线索、嗅觉敏感性和对天然气味的行为偏好之间的对应关系。具体目的是比较使用不同寄主植物的同一物种种群：(1)对寄主植物特异性挥发物的神经生理反应；(2)不同神经生理反应背后的分子遗传机制；(3)确定引起不同神经生理反应的挥发物是否转化为行为歧视。这些研究将有助于进一步了解周围神经系统如何随着生态环境的变化而变化，以及这些变化如何导致种群分化。

The perception of chemicals in the environment is a principal way in which many animals gain information from their surroundings. How an animal behaviorally responds to these signals may affect their reproductive success. An example of this is the preference insects have for distinct plants they feed on, based on the chemical compounds emitted from these plants. Specifically, changes in their preferences for chemical signals through changes in their ability to perceive them using their sense of smell (olfaction) can contribute to divergence among populations and species formation. This study will examine the evolution of the olfactory system within a single species, in the context of differences in chemical cues across its geographical range. This knowledge is fundamental to understanding more broadly how genetic and neural variation can result in fundamental differences in behavior. Results from the proposed work will thus document mechanisms by which a species emerges. It will also have broad implications for applied agriculture. Many herbivorous insects locate food and mates using their sense of smell, resulting in adverse effects on agricultural productivity. In summary, in addition to advancing the understanding of olfaction, this research will serve as a model for understanding the mechanisms underlying divergence in behavior and ecological speciation. Moreover, its integrative nature makes it ideally suited for training students, since it uses behavioral, molecular genetic, and neurophysiological approaches. Outreach activities will include exposing high school students to research through hands-on experiential learning that highlights results from the proposed research and, more broadly, concepts in sensory biology and evolution.Understanding species formation ideally includes examination of the process prior to its completion. Four geographically distinct populations of the fly Drosophila mojavensis currently exploit four different cactus species that emit specific combinations of volatile chemical compounds that are primary cues for plant identification. The objective of this proposal is to determine the correspondence between variation in olfactory cues, olfactory sensitivity, and behavioral preference for natural odorants. The specific aims are to compare populations of the same species that use different host plants: (1) neurophysiological responses to host plant-specific volatiles, (2) molecular genetic mechanisms underlying different neurophysiological responses, and (3) to determine whether the volatiles eliciting different neurophysiological responses translate into behavioral discrimination. These studies will result in further understanding of how the peripheral nervous system can change in response to changing ecological environments, and how these changes may contribute to population divergence.