Analysis of a Large Family of Candidate Taste Receptors

描述（由申请人提供）：该项目的长期目标是阐明味觉系统功能和组织的基本原理。该实验计划利用果蝇作为模型系统，可以对单个味觉细胞进行强大的分子遗传分析和生理测量。了解昆虫的味道也可能有助于控制人类疾病的昆虫媒介，这些媒介从人类宿主那里接收味觉信号。 该项目通过三个具体目标来解决味觉编码的分子和细胞逻辑。第一个目标是通过果蝇味觉感受器的生理记录构建味觉器官的功能图。该分析应确定功能上可区分的味觉感受器的数量以及这些感受器内神经元组织的定型程度。第二个目标是通过将单个 Gr（味觉受体）蛋白映射到已识别的味觉细胞来阐明这种细胞组织的分子基础。这一分析将检验以下假设：单个味觉细胞表达多种味觉受体，并且某些受体在每个感器的多个神经元中表达。 第三个目标是通过遗传和异源表达分析来鉴定所选 Gr 基因的配体。该计划旨在研究味觉受体的调节广度（味觉编码中的一个关键问题），并允许进一步测试单个味觉神经元表达多种功能受体的假设。

DESCRIPTION (provided by applicant): The long-term goal of this project is to elucidate basic principles of taste system function and organization. The experimental plan takes advantage of the fruit fly Drosophila as a model system, which allows powerful molecular genetic analysis and physiological measurement of individual taste cells. Understanding of insect taste may also be useful in controlling insect vectors of human disease, which receive gustatory cues from their human hosts. The project addresses the molecular and cellular logic of taste coding through three specific aims. The first aim is to construct a functional map of the taste organs, through physiological recordings from the fly's taste sensilla. This analysis should determine the number of functionally distinguishable taste sensilla and the extent to which the organization of neurons within these sensilla is stereotyped. The second aim is to elucidate the molecular underpinnings of this cellular organization by mapping individual Gr (Gustatory receptor) proteins to identified taste cells. This analysis will test the hypothesis that individual taste cells express multiple taste receptors, and that some receptors are expressed in more than one neuron per sensillum. The third aim is to identify ligands for selected Gr genes, through genetic and heterologous expression analysis. The plan is designed to investigate the tuning breadth of taste receptors, a critical issue in taste coding, and to allow further testing of the hypothesis that individual taste neurons express multiple functional receptors.