Analysis of a Large Family of Candidate Taste Receptors

描述(由申请者提供)：本项目的长期目标是阐明品味系统的基本原理、功能和组织。该实验计划利用果蝇作为模型系统，可以对个体味觉细胞进行强大的分子遗传分析和生理测量。对昆虫味道的了解也可能有助于控制昆虫传播人类疾病的媒介，这些媒介从人类宿主那里接收味觉线索。 该项目通过三个具体目标解决味觉编码的分子和细胞逻辑。第一个目标是通过苍蝇味觉感受器的生理记录，构建味觉器官的功能图谱。这项分析应该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的组织在多大程度上被定型。第二个目标是通过将单个Gr(味觉受体)蛋白定位到已识别的味觉细胞来阐明这种细胞组织的分子基础。这项分析将检验这样一种假设，即单个味觉细胞表达多个味觉受体，而一些受体在每个感受器上表达的神经元不止一个。 第三个目标是通过遗传和异源表达分析，确定选定的GR基因的配体。该计划旨在研究味觉感受器的调谐宽度，这是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感受器的假设。

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.