DIFFERENTIATION OF THE JUNCTIONAL COMPLEX OF SURFACE CELLS IN THE DEVELOPING FUNDULUS BLASTODERM
DIFFERENTIATION OF THE JUNCTIONAL COMPLEX OF SURFACE CELLS IN THE DEVELOPING FUNDULUS BLASTODERM
复制标题
发育中的眼底胚层表面细胞连接复合体的分化
作者：
T. Lentz;J. Trinkaus
本文研究了硬骨鱼Fundulus heteroclitus囊胚、中期原肠胚、晚期原肠胚和早期胚胎表面细胞间连接复合体的结构。在囊胚中，细胞间复合体是简单的，包括一个顶端区域，在那里相邻的膜紧密贴靠（40 - 60 A），并在接触的地方，一个中间区，具有较宽的细胞间隙（> 100 A），和早期的桥粒。在原肠胚中，沿着复合体的顶端区沿着有频繁的膜融合点。沿着中间带，在发育的不同阶段，桥粒的扩张和数量增加。在原肠胚中期，在桥粒的水平下方存在一个细胞间隙为20 A的紧密连接或间隙连接。在原肠胚晚期，差距连接的程度减少，桥粒更好地发展。在早期胚胎中，复合体的基本组织是相同的，尽管位于深处的紧密连接不再明显，桥粒及其相关的细丝系统发育良好。此时，连接复合体与许多上皮细胞的连接复合体相当，由顶端闭合小带、短粘附小带和深层粘附斑组成。
The structure of the junctional complex between surface cells was investigated in blastula, mid gastrula, late gastrula, and early embryo of the teleost fish Fundulus heteroclitus. In blastulae, the intercellular complex is simple and consists of an apical region where the adjacent membranes are closely apposed (40–60 A) and in places touch, an intermediate zone with a wider intercellular space (> 100 A), and incipient desmosomes. In gastrulae, there are frequent points of fusion of membranes along the apical zone of the complex. Dilatations and an increased number of desmosomes in different stages of development are found along the intermediate zone. In mid gastrula, a close or gap junction with an intercellular space of 20 A occurs below the level of the desmosomes. In late gastrula, the gap junction is reduced in extent and desmosomes are better developed. In the early embryo, the basic organization of the complex is the same, although the deeply situated close junctions are no longer apparent and desmosomes and their associated system of filaments are well developed. At this time, the junctional complex is comparable to that of many epithelia and consists of an apical zonula occludens, a short zonula adherens, and deeply situated maculae adherentes.