Ono K, Bansal R, Payne J, Rutishauser U, Miller R H
Department of Neuroscience and Genetics, Case Western Reserve University, Cleveland OH 44106, USA.
Development. 1995 Jun;121(6):1743-54. doi: 10.1242/dev.121.6.1743.
Oligodendrocytes, the myelinating cells of the vertebrate CNS, originally develop from cells of the neuroepithelium. Recent studies suggest that spinal cord oligodendrocyte precursors are initially localized in the region of the ventral ventricular zone and subsequently disperse throughout the spinal cord. The characteristics of these early oligodendrocyte precursors and their subsequent migration has been difficult to assay directly in the rodent spinal cord due to a lack of appropriate reagents. In the developing chick spinal cord, we show that oligodendrocyte precursors can be specifically identified by labeling with O4 monoclonal antibody. In contrast to rodent oligodendrocyte precursors, which express O4 immunoreactivity only during the later stages of maturation, in the chick O4 immunoreactivity appears very early and its expression is retained through cellular maturation. In embryos older than stage 35, O4+ cells represent the most immature, self-renewing, cells of the chick spinal cord oligodendrocyte lineage. In the intact chick spinal cord, the earliest O4+ cells are located at the ventral ventricular zone where they actually contribute to the ventricular lining of the central canal. The subsequent migration of O4+ cells into the dorsal region of the spinal cord temporally correlates with the capacity of isolated dorsal spinal cord to generate oligodendrocytes in vitro. Biochemical analysis suggests O4 labels a POA-like antigen on the surface of chick spinal cord oligodendrocyte precursors. These studies provide direct evidence for the ventral ventricular origin of spinal cord oligodendrocytes, and suggest that this focal source of oligodendrocytes is a general characteristic of vertebrate development.
少突胶质细胞是脊椎动物中枢神经系统的髓鞘形成细胞，最初由神经上皮细胞发育而来。最近的研究表明，脊髓少突胶质细胞前体细胞最初定位于腹侧脑室区，随后分散至整个脊髓。由于缺乏合适的试剂，在啮齿动物脊髓中直接检测这些早期少突胶质细胞前体细胞的特征及其后续迁移一直很困难。在发育中的鸡脊髓中，我们发现少突胶质细胞前体细胞可以通过用O4单克隆抗体标记来特异性识别。与仅在成熟后期表达O4免疫反应性的啮齿动物少突胶质细胞前体细胞不同，在鸡中，O4免疫反应性出现得非常早，并且其表达在细胞成熟过程中一直保留。在35期以上的胚胎中，O4+细胞代表鸡脊髓少突胶质细胞谱系中最不成熟、自我更新的细胞。在完整的鸡脊髓中，最早的O4+细胞位于腹侧脑室区，它们实际上构成了中央管的室管膜内衬。O4+细胞随后向脊髓背侧区域的迁移在时间上与分离的背侧脊髓在体外产生少突胶质细胞的能力相关。生化分析表明，O4标记了鸡脊髓少突胶质细胞前体细胞表面的一种POA样抗原。这些研究为脊髓少突胶质细胞起源于腹侧脑室提供了直接证据，并表明这种少突胶质细胞的局灶性来源是脊椎动物发育的一个普遍特征。
