The regulation of synaptic specificity in the mammalian retina

摘要 建立适当的视网膜回路仍然是视觉系统发育的中心问题。神经元如何找到 他们的正确目标在很大程度上仍然未知。视网膜中的第一个突触提供了一个简单的， 实验上易于处理的系统，探索突触特异性的基础。视杆和视锥光感受器 选择性地分别与视杆双极和视锥双极形成突触。为了确定分子机制 介导特异性，我生成了不同光感受器的转录组图谱， 突触发生过程中的双极细胞靶点。从这些数据中，我发现了不同的转录本编码细胞表面 和分泌的蛋白质作为这一过程的有希望的候选者。使用体内基因操作， 发展的方法，我将评估这些基因在建立适当的连接功能。从 我的初步筛选，我发现以下：1）非典型的Wnt信号之间的杆和杆双极是 负责决定突触层的位置，2）视杆细胞中的Rspo 2参与层分离， 3）视锥中的Nrcam介导视锥双极的选择性连接。我把这个建议分成两部分 我在Aim 1中研究了杆-杆双极连接，在Aim 2中讨论了锥-锥双极连接。 目标2.每个目标的第一部分涉及扩展我的初步发现，并将在 K99阶段。第二部分涉及继续筛选和扩大新的表型， 在S博士的指导下发起的。劳伦斯Zipursky和将在R 00阶段完成。 该项目旨在帮助Zuniga-Sanchez博士获得终身助理职位 顶级学术研究机构的教授。在导师和咨询委员会的帮助下， 已经产生了有希望的数据，并在她的研究中取得了重大进展。作为独立调查员， 她计划继续研究哺乳动物视网膜的发育， 人体健康在K99阶段，她将继续受益于发展视觉 齐普斯基博士的系统她还将定期接受额外的职业和科学指导 与她的咨询委员会举行会议和介绍会。Zuniga-Sanchez博士将参加职业生涯 通过加州大学洛杉矶分校提供的发展研讨会，准备申请教师职位，并过渡到 R 00阶段。该拨款提案概述了培训，资源和合作网络， 让祖尼加-桑切斯博士成为视觉领域的独立调查员

Abstract Establishing proper retinal circuitry remains a central issue in visual system development. How neurons find their correct target remains largely unknown. The first synapse in the retina provides a simple and experimentally tractable system to explore the basis of synaptic specificity. Rod and cone photoreceptors synapse selectively with rod bipolars and cone bipolars, respectively. To identify the molecular mechanism mediating specificity, I generated transcriptome profiles of the different photoreceptors and their corresponding bipolar cell targets during synaptogenesis. From these data sets, I find distinct transcripts encoding cell surface and secreted proteins as promising candidates for this process. Using in vivo genetic manipulations and developmental approaches, I will assess the function of these genes in establishing proper connectivity. From my initial screen, I find the following: 1) non-canonical Wnt signaling between rods and rod bipolars is responsible for dictating the position of the synaptic layer, 2) Rspo2 in rods is involved in layer segregation, and 3) Nrcam in cones mediates selective connectivity to cone bipolars. I subdivided this proposal into two parts where I study rod-to-rod bipolar connectivity in Aim 1 and address cone-to-cone bipolar connectivity in Aim 2. The first section of each aim involves expanding on my preliminary findings and will be completed in the K99 phase. The second part involves continue screening and expanding on the new phenotypes which will be initiated under the mentorship of Dr. S. Lawrence Zipursky and will be completed during the R00 phase. This project has been designed to facilitate Dr. Zuniga-Sanchez to obtain a position as a tenure-track Assistant Professor at a top-tier academic research institution. With the help of her mentor and Advisory Committee, she has generated promising data and made significant progress on her research. As an independent investigator, she plans to continue her work studying the development of the mammalian retina with a clear relevance to human health. During the K99 phase, she will continue benefiting from the mentorship on the developing visual system from Dr. Zipursky. She will also receive additional career and scientific guidance at regular scheduled meeting and presentations with her Advisory Committee. Dr. Zuniga-Sanchez will participate in career development workshops offered through UCLA in preparation to apply for faculty positions and transitioning to the R00 phase. This grant proposal outlines the training, resources, and network of collaborations needed to establish Dr. Zuniga-Sanchez as an independent investigator in the vision field.