Axon Guidance in the Drosophila Visual System

果蝇视觉系统中的轴突引导

• 批准号: 9982093
• 负责人: Jessica Treisman
• 金额: $ 30万
• 依托单位: New York University Medical Center
• 依托单位国家: 美国
• 项目类别: Continuing grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-07-01 至 2003-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9982093&HistoricalAwards=false
• 关键词: Axon; Guidance; Drosophila; Visual; System

Treisman9982093The accurate transmission of information within the nervous system depends on the precise connections that neurons make with each other. To form these connections, axons must navigate over long distances to their target regions during development. Both long-range attractive or repulsive molecules, and short-range cues promoting selective adhesion, can guide axon outgrowth. The connections formed in the visual system are particularly intriguing, as they result in a precise mapping of the retina onto the brain, suggesting that each cell can sense its global position. Our understanding of the determinants of this positional information is far from complete. A genetic approach using the fruit fly Drosophila has the potential to identify new components mediating axon guidance, purely on the basis of their function. A genetic screen for mutations affecting the connections formed by photoreceptor axons in Drosophila has been initiated. The screen uses a mosaic approach that allows the identification of mutations in genes that are also required earlier in development. This screen is also rapid and favors the isolation of mutations that have defects specific to axon pathfinding. Mutations in two genes that control a pathfinding step specific to a particular photoreceptor have been identified. The proteins encoded by these genes will now be characterized in order to understand the basis for their functions in axon guidance. The screen will also be continued to obtain a more complete picture of the genetic requirements for the visual system projection pattern.

Treisman9982093神经系统内信息的准确传输取决于神经元之间的精确连接。为了形成这些连接，轴突在发育过程中必须长距离导航到目标区域。长程吸引或排斥分子，以及促进选择性粘附的短程线索，都可以引导轴突生长。视觉系统中形成的连接特别有趣，因为它们可以将视网膜精确映射到大脑，这表明每个细胞都可以感知其全局位置。我们对这种位置信息的决定因素的理解还远未完成。使用果蝇的遗传方法有可能纯粹根据其功能来识别介导轴突引导的新成分。 已经开始对影响果蝇光感受器轴突形成的连接的突变进行基因筛查。该筛选采用镶嵌方法，可以识别发育早期所需的基因突变。这种筛选速度也很快，有利于分离具有轴突寻路特异性缺陷的突变。已经确定了控制特定光感受器特异寻路步骤的两个基因的突变。现在将对这些基因编码的蛋白质进行表征，以便了解它们在轴突引导中的功能基础。该屏幕还将继续获得关于视觉系统投影模式的遗传要求的更完整的图片。