NEURAL RETINA RECOGNITION PROTEIN, COGNIN, IN DEVELOPMEN

多细胞动物的生化和生理过程需要 许多细胞之间的协调互动。 维持这些细胞 由它们产生的特定细胞连接的关联是 组织功能的基础。 本项目的目的是确定 一种特定的胚胎细胞表面成分在控制 视网膜细胞识别，以及神经元的发育 连接. 我们已经纯化了这种成分，神经视网膜认知素; 它是一种糖蛋白，可增强分离的鸡的再聚集 和小鼠神经视网膜细胞。 扫描电子显微镜 细胞表面cognin的定位表明，它的分布在 视网膜，在不同的视网膜细胞类型，以及这种变化， 分布在发展过程中，可能是重要的阐明作用， cognin in vivo体内 我们建议，首先，确定其他细胞表面 必须与认知蛋白相互作用的分子，从而重建 细胞-细胞识别机制。 这将通过亲和力来完成 色谱，以确定分子的结合cognin，并通过研究 简单的模型系统，在体外相互作用的膜囊制备 从视网膜细胞。 我们还将利用现有的多行列式 cognin的抗体，以确定cognin在体内的定位。 这 将与分离自以下的细胞类型上的同源蛋白分布进行比较： 通过密度梯度分离来测量视网膜，以确定 cognin在视网膜两个关键形态发生阶段中的作用 发展 这些是：视网膜和视网膜之间的早期诱导相互作用， 和其他视区组织，以及分层 成熟视网膜的结构。 最后，我们建议测试一个特定的 认知蛋白在突触发育后期起作用的假说 视网膜生成

Biochemical and physiological processes in multicellular animals require the coordinated interactions of many cells. Maintenance of these cell-cell associations of the specific cell junctions which arise from them is the basis of tissue function. The purpose of this Project is to determine the role of one specific embryonic cell surface constituent in the control of retina cell-cell recognition, and in the development of neuronal connections. We have purified this constituent, the neural retina cognin; it is a glycoprotein which enhances the reaggregation of dissociated chick and mouse neural retina cells in vitro. Scanning electron microscopy localization of the cell surface cognin suggests that its distribution in the retina, on differnt retina cell types, and the changes in such a distribution during development, may be significant in elucidating the role of cognin in vivo. We propose, first, to identify other cell surface molecules which must interact with cognin, and to thereby reconstruct the mechanism of cell-cell recognition. This will be done by affinity chromatography to identify molecules which bind cognin, and by studying a simple model system, the in vitro interaction of membranevesicles prepared from retina cells. We will also utilize the available polydeterminant antibody to cognin to determine the localization of cognin in vivo. This will be compared to the distribution of cognin on cell types isolated from the retina by density gradient fractionation in order to determine the possible role of cognin in two critical morphogenetic phases of retina development. These are; the early inductive interactions between retina and other optic area tissues, and the development of the stratified architecture of the mature retina. Finally, we propose to test a specific hypothesis that cognin plays a role in the development of synapses later retinogenesis.