Fluidity of the Neural Epithelium During Forebrain Formation in Rat Embryos
Fluidity of the Neural Epithelium During Forebrain Formation in Rat Embryos
复制标题
大鼠胚胎前脑形成过程中神经上皮的流动性
DOI：
10.1242/jcs.1987.supplement_8.24
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发表时间：
1987
影响因子：
4
通讯作者：
F. Tuckett
中科院分区：
文献类型：
--
作者：
Gillian M. Morriss‐Kay;F. Tuckett
摘要在大鼠胚胎神经形成期间，前脑的生长速度比仅通过内在细胞分裂所能解释的更快，而相邻的中脑/喙后脑尽管有丝分裂指数高（整个神经上皮细胞的细胞周期时间为6 h），但仍保持恒定的细胞数量。我们已经提出，神经上皮细胞流在中脑/喙后脑区域内的喙方向，朝向并进入迅速扩大的前脑。支持这一假设的证据是由细胞标记的研究：标记的神经上皮细胞被注射到特定的网站在中脑或吻后脑神经上皮的未标记的胚胎，这些胚胎培养24小时后，标记的细胞被发现在注射部位的位置。在中脑/喙后脑区域，有丝分裂纺锤体被发现主要是定向平行于胚胎的长轴，横向取向的纺锤体更频繁地观察到靠近侧边缘比更内侧。神经嵴细胞在神经形成时从外侧边缘迁移。这些观察结果表明，有丝分裂纺锤体的方向反映了细胞运动的方向：在横向区域中，向侧缘的运动将保持横向平面中的细胞数量，因为神经嵴细胞迁移;在其他地方，细胞主要在纵向平面中移动，朝向前脑。细胞运动和有丝分裂纺锤体方向之间可能的因果关系进行了讨论。将完整神经上皮内的细胞流与肠绒毛上皮中的细胞流进行比较。在神经形成期间在颅神经上皮中观察到的其他类型的上皮细胞运动包括与细胞形状和微生物介导的曲率的变化相关的上皮表面的膨胀和收缩。涉及邻居交换的细胞重排和朝向上皮-间充质转化位点的细胞移动也有牵连。
SUMMARY During neurulation in rat embryos, the forebrain grows more rapidly than can be accounted for by intrinsic cell division alone, while the adjacent midbrain/rostral hindbrain maintains a constant cell number despite a high mitotic index (the cell cycle time is 6 h throughout the neural epithelium). We have proposed that neuroepithelial cells flow in a rostral direction within the midbrain/rostral hindbrain region, towards and into the rapidly expanding forebrain. Evidence in support of this hypothesis is provided by cell-labelling studies: labelled neuroepithelial cells were injected into specific sites in the midbrain or rostral hindbrain neuroepithelium of unlabelled embryos; after culture of these embryos for 24 h, the labelled cells were found in positions rostral to the injection sites. In the midbrain/rostral hindbrain region, mitotic spindles were found to be predominantly orientated parallel with the long axis of the embryo; transversely orientated spindles were more frequently observed close to the lateral edges than more medially. Neural crest cells emigrate from the lateral edges during neurulation. These observations suggest that mitotic spindle orientation reflects the direction of cell movement: in the lateral region movement towards the lateral edge would maintain cell number in the transverse plane as neural crest cells emigrate; elsewhere, cells are moving mainly in the longitudinal plane, towards the forebrain. The possible causal relationship between cell movement and mitotic spindle orientation is discussed. Cell flow within the intact neural epithelium is compared with cell flow in the intestinal villus epithelium. Other types of epithelial cell movement observed in the cranial neural epithelium during neurulation include expansion and shrinkage of the epithelial surface associated with change of cell shape and microfilament-mediated curvature. Cell rearrangement involving exchange of neighbours and cell movement towards and into a site of epithelio–mesenchymal conversion are also implicated.
非洲爪蟾表皮细胞的体外和原位运动和细胞-基质接触。
影响因子：
4
作者：
Radice,GP
通讯作者：
Radice,GP