Patterning the retina for color vision

为色彩视觉设计视网膜图案

• 批准号: 6938489
• 负责人: Claude Desplan
• 金额: $ 37.7万
• 依托单位: NEW YORK UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-09-01 至 2008-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6938489
• 关键词: Drosophilidae; arthropod genetics; behavior test; behavioral /social science research tag; biological signal transduction; chimeric proteins; circadian rhythms; color visions; gene expression; gene mutation; genetic screening; larva; molecular cloning; neural information processing; optical polarization; protein structure function; retina; rhodopsin; site directed mutagenesis; technology /technique development; transposon /insertion element; visual perception; visual photoreceptor

DESCRIPTION (provided by applicant): The major task of the visual system is to build a spatial map of the environment: A precise retinotopic map projects an image of the retina onto the optic lobes. We are concerned with the qualitative map built by the Drosophila visual system for color vision and recognition of the vector of polarized light. The rhodopsins expressed in the inner photoreceptors (PR's) R7 and R8 defines functionally distinct ommatidia that are involved in color vision. To address how the visual system integrates information about the quality of light, we offer the following aims: 1. Mutual exclusion of rhodopsins: We will study how Rhodopsin proteins are involved in the process of excluding expression of other rh's in the same cell and what the downstream events are. This function represents a paradigm that might be of interest for other sensory systems that use similar types of receptors. 2. Signaling pathway between R7 and R8: We have isolated a series of mutants that affect the communication between R7 and R8 in opposite ways without affecting R7 rh expression. We will characterize this cascade of genes genetically and molecularly, both in the adult retina and in the larval eye that represents a highly simplified visual system. 3. A behavior assay for color vision: We will develop a behavior assay for color vision. We will use our collection of mutants and appropriate genetic tools to evaluate the function of the different subclasses of ommatidia and analyze new mutants that affect color processing in the medulla. Finally, we will test the role of the two classes of PR's in the larval eye to entrain the circadian clock at different times of day. 4. A new screen to identify mutations affecting rh expression: We have designed an insertional mutagenesis recessive mosaic screen based on a new universal transposable element piggyBac with a different insertional specificity than P-elements. This screen will aid us in cloning genes from the previous screen as well as for identifying new mutants. This system represents a simple paradigm to a basic problem of sensory perception using a very amenable genetic system that has so far not been used for the study of color vision. As the nocturnal mouse model is not appropriate for studying color vision, this places Drosophila in a unique position for such experimental manipulations.

描述（由申请人提供）：视觉系统的主要任务是建立环境的空间图：精确的视网膜定位图将视网膜的图像投射到视叶上。我们关注的是果蝇视觉系统建立的颜色视觉和偏振光矢量识别的定性地图。在内部光感受器（PR）R7和R8中表达的视紫红质定义了参与色觉的功能不同的小眼。为了解决视觉系统如何整合有关光的质量的信息，我们提供了以下目标：1。视紫红质的相互排斥：我们将研究视紫红质蛋白如何参与排除同一细胞中其他rh表达的过程以及下游事件是什么。这种功能代表了一种范式，可能对使用类似类型受体的其他感觉系统感兴趣。2. R7和R8之间的信号通路：我们已经分离出一系列突变体，它们以相反的方式影响R7和R8之间的通信，而不影响R7 rh表达。我们将从基因和分子的角度来描述这种级联反应，包括成年视网膜和代表高度简化的视觉系统的幼虫眼睛。3.色觉的行为测定：我们将开发色觉的行为测定。我们将使用我们收集的突变体和适当的遗传工具来评估小眼不同亚类的功能，并分析影响髓质颜色处理的新突变体。最后，我们将测试两类PR在幼虫眼中的作用，以在一天中的不同时间引导生物钟。4.一个新的屏幕，以确定影响rh表达的突变：我们已经设计了一个插入突变隐性镶嵌屏幕的基础上，一个新的通用转座因子piggyBac具有不同的插入特异性比P-元件。这个屏幕将帮助我们在克隆基因从以前的屏幕以及识别新的突变体。这个系统代表了一个简单的范例，一个基本的问题，感官知觉使用一个非常顺从的遗传系统，迄今尚未被用于研究色觉。由于夜间小鼠模型不适合研究色觉，这使得果蝇在这种实验操作中处于独特的位置。