Kalnins V I, Opas M, Ahmet I, Fedoroff S
J Neurocytol. 1984 Dec;13(6):867-82. doi: 10.1007/BF01148590.
The organization of microfilaments using NBD-phallacidin and cell adhesion to substratum by surface reflection interference microscopy was examined during differentiation of astrocytes in colony cultures and correlated with motile behaviour of cells. Disaggregated cells from neopallium of 12-day-old or newborn DBA/1J mouse embryos were used to establish colonies and astrocyte precursor cells at various stages of differentiation along the astrocyte lineage were examined after 3 days, 1, 2 and 4 weeks in culture. The earliest astrocyte precursor cells, the glioblasts, are stationary and form epithelial-type colonies which adhere to the substratum primarily around the edge where large microfilament bundles are found. Bundles of microfilaments are also present around the apical ends of closely packed cells. As the epithelial cells start to separate and transform into flat proastroblasts, adherens-type junctions which have a zig-zag appearance and are associated with microfilaments form between adjacent cells. In the highly motile astroblasts these junctional regions break down into multiple smaller regions where the separated cells remain in contact through fine processes. The astroblasts also have stress fibres, focal contacts with substratum, foci from which microfilament bundles radiate and a complex pattern of fine, circumferentially oriented bundles of microfilaments. This elaborate organization of microfilaments disappears as the motile astroblasts differentiate into stationary fibrous astrocytes that have little polymerized actin and lack focal contacts. These results show that stationary astrocyte precursor cells in vitro go through a highly motile stage having a characteristic distribution of microfilaments and focal contacts before becoming stationary again. We consider that the motile stage could correspond to the stage in vivo when astrocyte precursor cells migrate from the ventricular and subventricular regions to take up position in different parts of the developing brain.
利用NBD-鬼笔环肽观察微丝的组织情况，并通过表面反射干涉显微镜检查集落培养中星形胶质细胞分化过程中细胞与基质的黏附情况，同时将其与细胞的运动行为相关联。使用来自12日龄或新生DBA/1J小鼠胚胎新皮层的分散细胞建立集落，并在培养3天、1周、2周和4周后检查沿星形胶质细胞谱系处于不同分化阶段的星形胶质细胞前体细胞。最早的星形胶质细胞前体细胞，即成胶质细胞，是静止的，形成上皮型集落，主要在边缘处与基质黏附，此处可发现大型微丝束。紧密排列的细胞顶端周围也存在微丝束。当上皮细胞开始分离并转化为扁平的前星形胶质细胞时，相邻细胞之间会形成具有锯齿状外观且与微丝相关的黏附连接。在高度运动的星形胶质细胞中，这些连接区域分解为多个较小的区域，分离的细胞通过细突起保持接触。星形胶质细胞还具有应力纤维、与基质的粘着斑、微丝束从中辐射的焦点以及复杂的微丝细束周向排列模式。随着运动的星形胶质细胞分化为静止的纤维性星形胶质细胞，这种微丝的精细组织消失，后者几乎没有聚合肌动蛋白且缺乏粘着斑。这些结果表明，体外静止的星形胶质细胞前体细胞在再次静止之前会经历一个高度运动的阶段，该阶段具有微丝和粘着斑的特征性分布。我们认为，运动阶段可能对应于星形胶质细胞前体细胞在体内从脑室和室下区域迁移到发育中大脑不同部位占据位置的阶段。
