Patterning the retina for color vision

为色彩视觉设计视网膜图案

• 批准号: 6795349
• 负责人: Claude Desplan
• 金额: $ 37.72万
• 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/6795349
• 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(申请人提供)：视觉系统的主要任务是构建环境的空间地图：精确的视网膜定位地图将视网膜的图像投影到视叶上。我们关注的是果蝇视觉系统为颜色视觉和偏振光矢量识别构建的定性地图。在内层光感受器(PR‘s)R7和R8中表达的视紫红质定义了与色觉有关的功能不同的小眼。为了解决视觉系统如何整合有关光质量的信息，我们提供了以下目标：1.视紫质的相互排斥：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的表达的过程以及下游事件是什么。这一功能代表了一种可能对其他使用类似类型感受器的感觉系统感兴趣的范例。2.R7和R8之间的信号转导途径：我们已经分离到一系列突变体，它们以相反的方式影响R7和R8之间的通讯，而不影响R7 Rh的表达。我们将从基因和分子上描述这一系列基因的特征，包括在成人视网膜和代表高度简化视觉系统的幼虫眼睛中。3.色觉行为测试：我们将开发一种色觉行为测试。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，并分析影响延髓颜色处理的新突变体。最后，我们将测试这两类PR在幼虫眼睛中的作用，以在一天的不同时间缠绕生物钟。4.一种新的筛选影响Rh表达的突变：我们设计了一种插入突变隐性镶嵌筛选，该筛选基于一种新的通用转座元件iggyBac，该元件具有不同于P-元件的插入专一性。这一筛选将帮助我们从前一次筛选中克隆基因，并识别新的突变体。这个系统代表了一个简单的范例，利用一个非常顺从的遗传系统来解决感官知觉的基本问题，到目前为止，这个遗传系统还没有被用于颜色视觉的研究。由于夜间活动的小鼠模型不适合研究颜色视觉，这使得果蝇在这种实验操作中处于独特的位置。