Cell-surface associated cxtracellular proteoglycan involved in migration of the cell

在鸡胚的嗅上皮、嗅神经以及产生嗅上皮并沿嗅神经向前脑迁移的细胞中发现了一种对单克隆抗体有免疫反应的神经蛋白多糖（PG）。胚胎日（ED） 3 ~ 3.5时，嗅神经束对PG出现免疫反应。ED5-11期间，神经束的免疫反应性逐渐增强。细胞表面相关的免疫反应性细胞外定位在ED6和之后的嗅觉上皮中可见。免疫荧光双标记PG和促性腺激素释放激素（GnRH）显示PG覆盖在GnRH细胞和其他沿嗅觉神经迁移的细胞的细胞体表面。电镜下可见PG在细胞体表面和神经束的神经突表面。这些结果表明，鸡胚中的神经PG是一种细胞表面相关的细胞外基质分子，PG覆盖在迁移细胞和伸长嗅神经的表面。在鼻区发现的PG细胞表面相关的细胞外定位，以及在大鼠脑中显示的PG与细胞粘附分子的结合特性，表明PG在鸡胚胎中引导细胞沿嗅觉神经迁移中起作用。

A neural proteoglycan (PG) immunoreactive to a monoclonal antibody was seen in the olfactory epithelium, the olfactory nerve, and the cells orignating the epithelium and migrating along the olfactory nerve toward the forebrain in chick embryos.Immunoreactivity to the PG appeared on embryonic day (ED) 3-3.5 in the bundles of the olfactory nerve.The immunoreactivity in the nerve bundles gradually increased during ED5-11.Cell surface-associated extracellular localization of the immunoreactivity was seen in the olfactory epithelium on ED6 and afterwards.Immunofluorescent double-labeling of the PG and gonadotropin-releasing hormone (GnRH) revealed that the PG covered the surface of the cell bodies of both GnRH-containing cells and other cells migrating along the olfactory nerve.Under an electron microscope, the PG was seen on the surfaces of the cell bodies and of the neurites in the nerve bundles.These results indicate that the neural PG in chick embryos is one type of cell surface-associated extracellular matrix molecule, and that the PG covered the surfaces of migrating cells and of elongating olfactory nerve.The cell surface-associated extracellular localization of the PG found in the nasal region, taken together with the binding properties of this PG with cell adhesion molecules shown in rat brains, suggested than the PG playd a role in guiding the migration of cells along the olfactory nerve in chick embryos.