Identification and function of sex pheromones and their receptors in Drosophila

昆虫不仅用它们的嗅觉和味觉来寻找它们赖以为生的动物或植物的寄主和寻找产卵的地点，而且还用它们来相互交流。交配是求爱成功的结果，而求爱依赖于雄性和雌性之间的交流。最近，我们发现果蝇（一种在生物学研究中广泛使用的昆虫）的嗅觉系统的很大一部分似乎专门用于闻到苍蝇的气味。这表明嗅觉性信息素可能在其繁殖行为中起着重要作用。本项目的目的是在果蝇中识别新的嗅觉性信息素，并分析它们在求偶中的功能。在果蝇的触角中，气味与气味受体相互作用，由气味受体基因（Or）家族编码。这些气味感受器在感觉神经元的膜中表达。神经元将气味的质量、强度和时间特征编码成电信号。嗅觉感觉神经元位于苍蝇的触角上被称为感受器的结构中，我们可以通过放置在感受器中的电极记录神经元的电活动。我们发现毛状感受器，这是一种形态类型，拥有对苍蝇气味做出反应的神经元。在毛状体中有12个或基因表达。我们将使用先前开发的分析系统来测试每个受体对苍蝇气味的敏感性。然后，我们将识别苍蝇气味中激活受体的成分。最后，在行为实验中，我们将探索果蝇如何使用它们的受体来区分合适和不合适的配偶。果蝇属于双翅目。双翅目还包括叮咬蝇和蚊子，它们传播疟疾、登革热和锥虫病（人类的“昏睡病”）等严重疾病。了解一种苍蝇的性信息素交流可能阐明双翅目昆虫求偶的一般原理，并可能通过为我们提供破坏昆虫繁殖行为的工具而产生新的昆虫控制策略。

Insects not only use their senses of smell and taste to find the animal or plant hosts from which they feed and to find sites for laying eggs, but also to communicate with each other. Mating is the outcome of successful courtship, and courtship depends on communication between males and females. Recently, we found that a large part of the olfactory system in the fruit fly Drosophila, an insect that is used widely in biological research, appears to be dedicated to smelling fly odours. This suggests olfactory sex pheromones may play an important role in its reproductive behaviour. The aim of this project is to identify new olfactory sex pheromones in Drosophila and to analyze their function in courtship. In the flies' antennae, odours interact with odor receptors, encoded by the Odor receptor gene (Or) family. These odor receptors are expressed in the membranes of sensory neurons. The neurons encode information about the quality, intensity and temporal characteristics of odours in electrical signals. The olfactory sensory neurons are located in the antenna of the fly in structures called sensilla, and we can record the electrical activity of the neurons through an electrode placed into the sensilla. We found that trichoid sensilla, which are one morphological type, hold neurons that respond to fly odours. There are twelve Or genes expressed in the trichoids. We will use a previously developed assay system to test each of the receptors' sensitivity to fly odours. We will then identify the components in the fly odours that activate the receptors. Finally in behavioural experiments, we will explore how the flies use their receptors to distinguish suitable from unsuitable mates. Fruit flies belong to the order of the Diptera. The Diptera also include biting flies and mosquitoes that transmit serious diseases such as malaria, dengue fever and trypanosomiasis ('sleeping sickness' in humans). An understanding of sex pheromone communication in one fly species may elucidate general principles of Dipteran courtship, and may lead to new strategies of insect control by giving us the tools to disrupt the insects' reproductive behaviour.