Hardin J, Keller R
Biophysics and Medical Physics Group, University of California, Berkeley 94720.
Development. 1988 May;103(1):211-30. doi: 10.1242/dev.103.1.211.
The behaviour of bottle cells in normal and microsurgically altered gastrulae and in cultured explants of Xenopus laevis was analysed, using time-lapse micrography, scanning electron microscopy (SEM) and cell tracing with fluorescein dextran amine (FDA). The results shed new light on the function of bottle cells. Bottle cells forming in vivo show a predominantly animal-vegetal apical contraction and a concurrent apical-basal elongation, whereas those forming in cultured explants show uniform apical contraction and remain rotund. Bottle cells forming in embryos with fewer subblastoporal cells contract more uniformly than those in normal embryos and release of normal bottle cells from supra- and subblastoporal cells results in immediate loss of the bottle shape. These results, and an analysis of the effects of bottle cell formation on the shapes and movements of surrounding tissues, show that unique shape of bottle cells and their probable function in development are not intrinsic properties but result from a modulation of the effect of a uniform and intrinsic apical contraction by the geometric and mechanical properties of the surrounding tissue. Mechanical simulations of bottle cell formation, using the finite element method, suggest how the site of bottle cell formation and the thickness and stiffness of adjacent tissues might change the effects of their formation. These results and FDA marking of prospective bottle cells and the adjacent deep mesodermal cells suggest that bottle cells function during their formation to initiate the involution of the prospective mesodermal mantle. Later they respread to deepen the archenteron and to form its peripheral wall.
利用延时显微摄影、扫描电子显微镜（SEM）以及用荧光素葡聚糖胺（FDA）进行细胞追踪，分析了非洲爪蟾正常和经显微手术改变的原肠胚以及培养外植体中瓶状细胞的行为。这些结果为瓶状细胞的功能提供了新的线索。在体内形成的瓶状细胞主要表现为动物极 - 植物极方向的顶端收缩以及同时发生的顶端 - 基部伸长，而在培养外植体中形成的瓶状细胞则表现为均匀的顶端收缩并保持圆形。在亚胚孔下细胞较少的胚胎中形成的瓶状细胞比正常胚胎中的收缩更均匀，并且正常瓶状细胞从胚孔上和胚孔下细胞脱离后会立即失去瓶状形态。这些结果以及对瓶状细胞形成对周围组织形状和运动影响的分析表明，瓶状细胞独特的形状及其在发育中的可能功能并非内在属性，而是周围组织的几何和机械特性对均匀且内在的顶端收缩作用进行调节的结果。使用有限元方法对瓶状细胞形成进行的力学模拟表明，瓶状细胞形成的部位以及相邻组织的厚度和刚度可能会如何改变其形成的影响。这些结果以及对预期瓶状细胞和相邻深层中胚层细胞的FDA标记表明，瓶状细胞在形成过程中发挥功能以启动预期中胚层套膜的内卷。之后它们重新铺展以加深原肠并形成其外周壁。
