Sensory Physiology and Genomics of Olfaction in Drosophila Mojavensis

对环境中化学物质的感知是许多动物从周围环境中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，基于这些植物释放的化学化合物。具体来说，通过改变它们使用嗅觉（嗅觉）感知化学信号的能力，它们对化学信号的偏好发生变化，这可能导致种群和物种形成之间的差异。这项研究将研究嗅觉系统的进化在一个单一的物种，在其地理范围内的化学线索的差异。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至关重要。因此，拟议工作的结果将记录物种出现的机制。 它也将对应用农业产生广泛的影响。许多食草昆虫利用嗅觉寻找食物和交配，对农业生产力产生不利影响。总之，除了推进对嗅觉的理解外，这项研究还将作为理解行为和生态物种形成差异的机制的模型。此外，它的综合性使其非常适合培训学生，因为它使用行为，分子遗传学和神经生理学方法。外联活动将包括让高中生通过亲身体验学习来了解研究，重点介绍拟议研究的结果，以及更广泛的感官生物学和进化概念。了解物种形成最好包括在完成之前对其过程进行检查。四个地理上不同的种群的果蝇mojavensis目前利用四个不同的仙人掌物种，排放特定的挥发性化合物的组合，是植物识别的主要线索。这个建议的目的是确定变化之间的对应关系，嗅觉线索，嗅觉灵敏度和行为偏好的天然气味。具体目的是比较使用不同寄主植物的同一物种的种群：（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。这些研究将进一步了解周围神经系统如何响应不断变化的生态环境而变化，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.