PHYSIOLOGY OF EXCITABLE MEMBRANE AND SYNAPSE

单基因突变可以用来改变任何给定的大分子或 兴奋性细胞中的细胞过程。一批合适的变种人 应该使我们能够剖析细胞结构或机制 利息。这项拟议的研究涉及果蝇突变体，它们具有 神经和肌肉中膜电流的特定缺陷。 在果蝇体内发现了三种不同的外向钾电流 肌肉。短暂性IA、延迟整流IK和钙依赖 IC。这些K+电流分别受Sh、EAG、Hk和Slo的影响 突变。我们将对这些电流进行电压钳位分析 以表征幼虫肌肉的激活和失活特性， 这些离子通道的离子选择性和药理敏感性 以及这些突变所改变的机制。使用膜片钳和 全细胞钳制技术我们将扩展这一分析以检查 突变对培养果蝇神经元K+通道的影响在……里面 此外，存在于神经中的钠电流的特定变化 但不包括肌肉，这是由nap ts和parts突变引起的，将进行研究。 单通道和全电池电流实验可以提供精辟的 分析这些突变改变的分子机制。 之前对果蝇的研究表明，某些类型的通道可能 由子单元组成，可以与其他渠道共享某些子单元 类型。这种可能性将通过研究 单基因突变对不同途径和不同基因突变的影响 一种由不同基因突变引起的通道类型。功能界别 通过对基因产物的分析，可以揭示基因产物之间的关系 同一基因的不同突变(等位基因)之间的相互作用 杂合子或双突变个体中不同基因的突变。 我们将尝试将这些功能分析与重组 EAG、帕金森和纳帕特斯等位基因的研究 为通道和相关蛋白质提供功能的结构。

Single-gene mutations can be used to alter any given macromolecule or cellular process in the excitable cells. A proper collection of mutants should enable us to dissect the cellular structures or mechanisms of interest. The proposed research involves Drosophila mutants that have specific defects in membrane currents in nerve and muscle. Three different outward K+ currents have been identified in Drosophila muscles. The transient IA, delayed rectification IK, and Ca++ -dependent IC. These K+ currents are separately altered by Sh, eag, Hk and slo mutations. We will conduct voltage-clamp analysis of these currents in larval muscles to characterize the activation and inactivation properties, ionic selectivity and pharmacological sensitivity of these ionic channels and the mechanisms altered by the mutations. Using the patch-clamp and whole-cell clamp techniques we will extend this analysis to examine the mutational effects on the K+ channels in cultured Drosophila neurons. In addition, the specific alterations in Na current, which is present in nerve but not muscle, caused by nap ts and para ts mutations will be studied. Single-channel and whole-cell current experiments can provide an incisive analysis of the molecular mechanisms altered by these mutations. Previous studies in Drosophila suggest that certain types of channels may be composed of subunits and may share some subunits with other channel types. This possibility will be further investigated by studying the effects of a single-gene mutation on different channels and alterations in a channel type caused by mutations of different genes. The functional relationship among the gene products can be revealed by analysis of inter-actions between different mutations (alleles) of the same gene or mutations of different genes in heterozygous or double-mutant individuals. We will attempt to integrate these functional analysis with the recombinant DNA studies of the alleles of eag, para ts and nap ts in order to relate structure to function for channels and related proteins.