The Light-Dependent Cation Channel of Fly Photoreceptors

感光细胞对光线的反应是一系列的步骤。 在脊椎动物眼中，环GMP是一种化合物， 光感受器，增加内部浓度时， 细胞被照亮。 cGMP浓度的增加， 触发了细胞膜通道的打开 因为离子带有电荷， 运动产生的电事件称为受体 潜力 人们对光依赖性阳离子通道知之甚少 在无脊椎动物的光感受器中，尽管无脊椎动物提供 我们有希望了解 发展和规范这一重要特征。 水果 果蝇因其在遗传学研究中的应用而闻名， 并且可获得多种突变株。 这个项目 将研究果蝇中依赖于光的阳离子通道， 体外开发的制剂， 膜片钳电生理技术用膜 录制. 通道打开和关闭的属性将是 并与脊椎动物进行了比较 光感受器 生化化合物将被鉴定， 控制通道的开放，以与cGMP的作用相比， 脊椎动物的光感受器 果蝇的视觉突变体 进行筛选，以确定可能的基因，决定 基因的结构或功能控制这一重要 膜组件 这项工作将直接导致承诺 基因操作的技术， 通道;这种蛋白质的分析在感觉重要 转导将对所有感觉科学产生重大影响。

A photoreceptor cell responds to light in a series of steps. In the vertebrate eye, cyclic GMP is a compound in the photoreceptors that increases in internal concentration when the cell is illuminated. The increased concentration of cGMP then triggers opening of channels in the cell membrane that allow ions to cross it. Since the ions carry electrical charge, their movement produces the electrical event called the receptor potential. Very little is known about the light-dependent cation channel in photoreceptors of invertebrates, although invertebrates offer the promise of understanding the genetic basis for the development and regulation of this important feature. The fruit fly, Drosophila, is well-known for its use in genetic studies, and a wide variety of mutant strains are available. This project will study light-dependent cation channel in flies, using a newly developed preparation in vitro that allows access to cell membranes for the electrophysiological technique of patch-clamp recording. The properties of channel opening and closing will be established and compared with those for vertebrate photoreceptors. Biochemical compounds will identified that control the opening of the channel to compare to the cGMP role in the vertebrate photoreceptors. Visual mutants of Drosophila will be screened to identify possible genes that determine the structure or function of the genes controlling this important membrane component. This work will lead directly to the promise of genetic manipulation allowing structural analysis of these channels; such analysis of proteins important in sensory transduction will have substantial impact on all sensory science.