Andries L, Harrisson F, Vakaet L
Laboratory of Human Physiology, University Centre of Antwerp, Antwerpen, Belgium.
Cell Biol Int. 1994 Jul;18(7):729-36. doi: 10.1006/cbir.1994.1102.
The spreading behaviour of dissociated hypoblast cells on and besides a band of aligned fibrils associated with the basal lamina of the epiblast was investigated by the use of scanning electron microscopy. A horse-shaped band of aligned fibrils, first demonstrated by Wakely and England (1979), is present during the gastrulation stages of chicken embryos on the ventral side of the epiblast at the cranial and lateral borders of the area pellucida. The basal lamina of the area pellucida situated inside the fibrillar band enables the spreading and probably the locomotion of dissociated cells, which appeared as polarized cells. Numerous cells were also found on the fibrillar band, and these cells lacked distinct lamellae and a polarized shape. Extensions of the cells contacted the extracellular fibrils and, at these sites of contact, the pattern of the fibrils was frequently deformed. From these observations and from previous results emerged the concept that spreading and locomotion of dissociated hypoblast cells, as well as single mesoblast cells and healing hypoblast epithelium, are inhibited by the band of extracellular fibrils, which acts as a physical barrier. The cell biological basis of the mechanism by which extracellular fibrils associated with the basal lamina arrest the migration of hypoblast and mesoblast cells, but guide the migration of primordial germ cells, is discussed.
利用扫描电子显微镜研究了分离的下胚层细胞在与上胚层基底层相关的排列成束的纤维带及其周围的扩散行为。一条马形的排列成束的纤维带，最早由Wakely和England（1979年）发现，在鸡胚原肠胚形成阶段，位于明区头侧和外侧边缘的上胚层腹侧。位于纤维带内的明区基底层能使分离的细胞扩散，可能还有移动，这些细胞呈现出极化细胞的形态。在纤维带上也发现了许多细胞，这些细胞没有明显的片状伪足和极化的形状。细胞的延伸部分与细胞外纤维接触，在这些接触部位，纤维的形态经常发生变形。从这些观察结果和先前的研究结果中得出这样一个概念：细胞外纤维带作为一种物理屏障，抑制了分离的下胚层细胞以及单个中胚层细胞和愈合的下胚层上皮细胞的扩散和移动。本文还讨论了与基底层相关的细胞外纤维阻止下胚层和中胚层细胞迁移，但引导原始生殖细胞迁移这一机制的细胞生物学基础。
