Kamei Y, Inagaki N, Nishizawa M, Tsutsumi O, Taketani Y, Inagaki M
Department of Obstetrics and Gynecology, Faculty of Medicine, The University of Tokyo, Japan.
Glia. 1998 Jul;23(3):191-9. doi: 10.1002/(sici)1098-1136(199807)23:3<191::aid-glia2>3.0.co;2-8.
Although accumulating data reveal patterns of proliferation, migration, and differentiation of neuronal lineage cells in the developing brain, gliogenesis in the brain has not been well elucidated. In the rat brain, vimentin is selectively expressed in radial glia and in their progeny, not in oligodendrocytes or neurons from embryonic day 15 (E15) until postnatal day 15 (P15). Here we examined mitotic radial glial lineage cells in the rat brain E17-P7, using the monoclonal antibody 4A4, which recognizes vimentin phosphorylated by a mitosis-specific kinase, cdc2 kinase. In the neocortex, mainly radial glia in the ventricular zone, but not their progeny, underwent cell division. In contrast, not only radial glia but also various types of radial glial progeny including Bergmann glia continued to proliferate in the cerebellum. Radial glia in the neocortex divided horizontally, obliquely, and vertically against the ventricular surface. The percentage of the vertical division increased with progress in the stage of development, concurrently with the decrease of the population of horizontal divisions. Thus, the monoclonal antibody 4A4 provides an useful tool to label mitotic glia in the developing brain and revealed different patterns of gliogenesis in the neocortex and cerebellum. A possibility is discussed that the dynamics of mitotic orientation observed here may be related to the change of the pattern of gliogenesis during development.
尽管越来越多的数据揭示了发育中大脑神经元谱系细胞的增殖、迁移和分化模式，但大脑中的神经胶质生成尚未得到充分阐明。在大鼠大脑中，波形蛋白在胚胎第15天（E15）至出生后第15天（P15）期间，选择性地表达于放射状胶质细胞及其后代，而少突胶质细胞或神经元中不表达。在此，我们使用单克隆抗体4A4检测了大鼠大脑E17 - P7期有丝分裂的放射状胶质细胞谱系细胞，该抗体可识别由有丝分裂特异性激酶cdc2激酶磷酸化的波形蛋白。在新皮层中，主要是脑室区的放射状胶质细胞进行细胞分裂，而不是它们的后代。相比之下，在小脑中，不仅放射状胶质细胞，而且包括伯格曼胶质细胞在内的各种类型的放射状胶质细胞后代都继续增殖。新皮层中的放射状胶质细胞相对于脑室表面进行水平、倾斜和垂直分裂。垂直分裂的百分比随着发育阶段的进展而增加，同时水平分裂的数量减少。因此，单克隆抗体4A4为标记发育中大脑的有丝分裂胶质细胞提供了一个有用的工具，并揭示了新皮层和小脑中不同的神经胶质生成模式。本文讨论了此处观察到的有丝分裂方向动态可能与发育过程中神经胶质生成模式变化相关的可能性。
