Analysis of a Large Family of Candidate Taste Receptors

描述(摘自申请者摘要)：该项目的长期目标 是阐明味觉功能的基本原理。详细分析了 最近发现的候选味觉受体GR家族被提出。这个 该提案解决了受体功能的基本问题，利用 果蝇作为实验系统的优势。对昆虫的认识 味道也可能有助于控制昆虫传播人类疾病的媒介，这 从它们的人类宿主那里接收味觉提示。 第一个目标是识别和分类OR基因家族的所有成员， 并描述它们的基因组结构。影响OR的现有突变 人们将寻找基因。 对GR基因的表达进行分析。最初，RT-PCR分析将是 用于确定有多少家庭成员在味觉器官中表达 果蝇。作为特异性的测试，突变体的味觉器官缺乏 将检查化学感觉神经元，以及某些非味觉组织。一个 主要目标是通过其他方法确认和扩展RT-PCR分析的结果 手段，尤指通过指示哪些细胞表达个体或 基因。原位杂交、免疫组织化学和报告基因融合 将进行实验，以确定个体或 基因在味觉神经元的亚群中表达，无论个体的味觉 神经元表达多个OR基因，以及OR蛋白是否定位于 味觉神经元的树突，与味觉感受器的预期一样。 OR蛋白实际上是味觉受体的假设将得到检验 直接通过分析已有的两个OR突变体，以及 过度表达个体或基因的苍蝇。对品味的回应 刺激将首先通过敏感的行为范式进行测试。如果突变 表型被检测，它们将通过生理分析进行检测 个体味觉神经元，在体内。如果下面的表达式或 GR基因的过度表达会产生一种特定的口味表型，然后 该项目将提供强有力的证据，证明GR蛋白实际上是有味道的 受体，一种受体的配体，将被识别，以及关于 我们将获得味觉感受器的特异性。

DESCRIPTION (From the Applicant's Abstract): The long-term goal of this project is to elucidate basic principles of gustatory function. A detailed analysis of the recently discovered GR family of candidate taste receptors is proposed. The proposal addresses fundamental issues of receptor function, taking advantage of the strengths of Drosophila as an experimental system. Understanding of insect taste may also be useful in controlling insect vectors of human disease, which receive gustatory cues from their human hosts. The first aim is to identify and classify all members of the OR gene family, and to characterize their genomic organization. Extant mutations affecting OR genes will be sought. The expression of GR genes will be analyzed. Initially, RT-PCR analysis will be used to determine how many family members are expressed in the taste organs of Drosophila. As a test of specificity, the taste organs of a mutant lacking chemosensory neurons will be examined, as will certain non-gustatory tissues. A major goal is to confirm and extend the results of RT-PCR analysis by other means, especially by means that indicate which cells express individual OR genes. In situ hybridization, immunohistochemistry, and reporter gene fusion experiments will be performed with a view to determining whether individual OR genes are expressed in subsets of taste neurons, whether individual taste neurons express multiple OR genes, and whether OR proteins localize to the dendrites of taste neurons, as expected of taste receptors. The hypothesis that OR proteins are in fact taste receptors will be tested directly, by analysis of two OR mutants that are already available, and of flies that overexpress individual OR genes. Responses to a panel of taste stimuli will be tested, initially by a sensitive behavioral paradigm. If mutant phenotypes are detected, they will be examined by physiological analysis of individual taste neurons, in vivo. If either the underexpression or overexpression of a GR gene produces a specific taste phenotype, then the project will provide strong evidence that GR proteins are in fact taste receptors, a ligand for a receptor will be identified, and information about the specificity of a taste receptor will be gained.