MOLECULAR MECHANISMS OF GRANULE CELL MIGRATION

描述(摘自申请者摘要)：建议的总体目标 研究是为了了解脊椎动物中神经元迁移的机制 大脑。两个广泛的目标是发现迁徙所需的基因 神经胶质底物上的中枢神经系统神经元并发展一种实验方法 对大量迁移的神经元进行实时原位成像。在之前 在这笔赠款的循环中，研究人员发现了一种Astroactin(ASTN)基因， 作为颗粒细胞沿神经胶质细胞迁移的神经元配体 导游。预测的ASTN蛋白结构有一个胞外区域。 包含两个潜在的糖基化位点，以及与 纤维连接蛋白III家族和EGF受体的黏附分子。这个 拟议研究的第一个目标是对一种 有针对性地删除ASTN，检查主要结构的大小，以及 小脑两种主要神经元--颗粒细胞和神经元的发育 浦肯野细胞。在初步研究中，他们发现了一种ASTN2，并 寻找其他家庭成员。在另一组实验中，他们将 用生化方法分离ASTN的神经胶质受体。最后，他们 会将它们长期以来对迁徙的兴趣扩展到体内环境， 使用新开发的基于计算机的方法跟踪大型 颗粒细胞队列，用GFP标记的逆转录病毒转移或 用GFP-ASTN“敲入”小鼠。新的成像实验应该会提供 关于颗粒细胞在体内运动的第一个信息，使用3D 大量细胞群的延时记录。 这些实验将共同产生关于神经元-神经胶质配体的信息 Astroactin及其在迁移中的作用。就像发现了另外三个 ASTROCTIN基因表明ASTN是基因家族的一部分，他们将 检查这些基因在功能上的冗余。神经胶质细胞的发现 受体将提供有关神经胶质细胞机制的基本信息 分化，对大脑发育和大脑都至关重要的信息 精神创伤。最后，能够实时查看颗粒细胞的运动 原位将告知轴突(平行纤维)之间的关系 颗粒神经元沿Bergmann神经胶质细胞的延伸和运动 纤维。

DESCRIPTION (from applicant's abstract): The overall goal of the proposed research is to understand the mechanism of neuronal migration in the vertebrate brain. Two broad goals are to discover the genes required for the migration of CNS neurons on glial substrates and to develop an experimental approach to imaging large cohorts of migrating neurons, in situ, in real time. In prior cycles of this grant, the investigator discovered a gene astrotactin (Astn), that functions as a neuronal ligand for granule cell migration along glial guides. The predicted protein structure of Astn has an extra cellular region containing two potential glycosylation sites, and regions of homology to adhesion molecules of the fibronectin III family and the EGF receptor. The first aim of the proposed research is to carry out a quantitative analysis of a targeted deletion of Astn, examining the size of primary structures, and the development of the two principal cerebellar neurons, the granule cell and the Purkinje cell. In preliminary studies, they discovered an Astn2 and are searching for other family members. In another group of experiments, they will use biochemical methods to isolate the glial receptor for ASTN. Finally, they will extend their long-standing interest in migration to the in vivo setting, using newly developed computer-based methods to follow the migration of large cohorts of granule cells, labeled with retroviral transfer of the GFP marker or with GFP-Astn "knock-in" mice. The new imaging experiments should provide the first information on the movements of granule cells in vivo, using 3D time-lapse recordings of large cohorts of cells. Together these experiments will generate information on the neuron-glial ligand astrotactin, and its role in migration. As the discovery of a three more astrotactin genes demonstrates that Astn is part of a gene family, they will examine the redundancy in function of these genes. The discovery of the glial receptor will provide fundamental information on mechanisms of glial differentiation, information critical to both brain development and brain trauma. Finally, being able to view the movements of granule cells in real time in situ will inform about the relationship between axon (parallel fiber) extension and the locomotion of the granule neuron down the Bergmann glial fiber.