Chenn A, McConnell S K
Department of Biological Sciences, Stanford University, California 94305, USA.
Cell. 1995 Aug 25;82(4):631-41. doi: 10.1016/0092-8674(95)90035-7.
Neurons in the mammalian central nervous system are generated from progenitor cells near the lumen of the neural tube. Time-lapse microscopy of dividing cells in slices of developing cerebral cortex reveals that cleavage orientation predicts the fates of daughter cells. Vertical cleavages produce behaviorally and morphologically identical daughters that resemble precursor cells; these symmetric divisions may serve to expand or maintain the progenitor pool. In contrast, horizontally dividing cells produce basal daughters that behave like young migratory neurons and apical daughters that remain within the proliferative zone. Notch1 immunoreactivity is distributed asymmetrically in mitotic cells, with Notch1 inherited selectively by the basal (neuronal) daughter of horizontal divisions. These results provide cellular and molecular evidence that cortical neurons are generated from asymmetric divisions.
哺乳动物中枢神经系统中的神经元由神经管管腔附近的祖细胞产生。对发育中的大脑皮质切片中的分裂细胞进行延时显微镜观察发现，分裂方向可预测子细胞的命运。垂直分裂产生行为和形态上相同的子细胞，这些子细胞类似于前体细胞；这些对称分裂可能有助于扩大或维持祖细胞库。相比之下，水平分裂的细胞产生的基底子细胞表现得像年轻的迁移神经元，而顶端子细胞则留在增殖区。Notch1免疫反应性在有丝分裂细胞中呈不对称分布，Notch1由水平分裂的基底（神经元）子细胞选择性继承。这些结果提供了细胞和分子证据，表明皮质神经元由不对称分裂产生。
