GENETIC ANALYSIS OF CHEMOSENSATION IN C ELEGANS

项目描述：本项目是为了研究Dauer形成通道， 线虫C. 优雅 幼虫是另一种L3幼虫阶段， 发育中的线虫在拥挤的条件下跟随， 饥饿 先前在几个实验室的工作已经导致了 鉴定一种诱导dauer的信息素和感觉神经元 调节进入道尔通道的线虫头部。 不适当地进入突变体的遗传上位性分析 dauer途径在信息素的情况下，或替代地，未能 在费洛蒙存在的情况下进入道尔通路， Dauer调节的遗传途径的描述。 的目的 目前的建议是进一步了解道尔途径， 在细胞和分子水平上。 这项研究是一个模型， 了解化学感受器的传导和调控的发展， 环境保护 具体目的如下：1）进一步表征产品 daf-11基因。 这已被证明是一个跨膜的quanylyl 一种被认为参与传递dauer信息素信号的环化酶 在感觉神经元中。 实验包括用抗体定位 转基因、结构/功能分析和遗传学的探索 与可能的靶基因tax-4相互作用，tax-4编码cGMP- 激活离子通道。 2)克隆并分析了两个基因， Dauer途径：daf-21，被认为具有与 转化为DAF-11和DAF-14，它们被认为在Dauer途径的分支中起作用， 和其他地方，作为TGF β信号通路的一部分。 3)延长 已知的感觉神经元下游的dauer通路的细胞焦点 通过激光烧蚀候选中间神经元的神经元。Interneurons 选择的将是那些具有适当突触模式的人 与感觉神经元的连接，以及那些被发现表达 Dauer遗传途径的分子组成部分。 4)新的基因 dauer通路将在遗传筛选中寻找，并放置在dauer 上位性分析的途径。 5)电生理学研究测试 Dauer信息素反应的信号转导模型将是 通过开发用于感觉的膜片钳方法进行 神经元，或通过研究人类的单个分子成分， 肾上皮细胞

DESCRIPTION: This project is to study the dauer formation pathway in the nematode C. elegans. The dauer is an alternative L3 larval stage that the developing nematode follows under conditions of crowding and starvation. Previous work in several laboratories has resulted in the identification of a dauer-inducing pheromone and sensory neurons in the head of the nematode that regulate entrance into the dauer pathway. Genetic epistasis analysis of mutants that inappropriately enter the dauer pathway in the absence of pheromone, or alternatively that fail to enter the dauer pathway in the presence of pheromone, has allowed description of a genetic pathway of dauer regulation. The aim of the present proposal is to further the understanding of the dauer pathway at the cellular and molecular levels. This research is a model for understanding chemosensory transduction and regulation of development by the environment. The specific aims are as follows: 1) Further characterize the product of the daf-11 gene. This has been shown to be a transmembrane quanylyl cyclase thought to be involved in transducing the dauer pheromone signal in sensory neurons. Experiments include localization with antibodies and transgenes, structure/function analysis, and exploration of genetic interactions with a possible target gene, tax-4, which encodes a cGMP- activated ion channel. 2) Molecularly clone and analyze two genes of the dauer pathway: daf-21, thought to have a function closely related to daf-11, and daf-14, thought to act in a branch of the dauer pathway, and elsewhere, as part of a TGFbeta signalling pathway. 3) Extend the known cellular focus of the dauer pathway downstream of the sensory neurons by laser ablation of candidate interneurons. Interneurons selected will be those with an appropriate pattern of synaptic connectivity to sensory neurons, and those which are found to express molecular components of the dauer genetic pathway. 4) New genes of the dauer pathway will be sought in a genetic screen and placed in the dauer pathway by epistasis analysis. 5) Electrophysiological studies to test models of signal transduction in response to dauer pheromone will be carried out by developing patch clamping methodology for sensory neurons, or by studying individual molecular components in human epithelial kidney cells.