爪蟾脊索在决定过程中和相邻细胞的关系  

INTERCELLULAR RELATIONSHIP OF NOTOCHORD DETERMINATION OF XENOPUS LAEVIS

作　　者：曾弥白[1] 周美云[1] 王莹 

机构地区：[1]中国科学院上海细胞生物学研究所,上海200031

出　　处：《实验生物学报》1995年第3期299-309,共11页Acta Biologiae Experimentalis Sinica

摘　　要：已经知道,对预定脊索的决定起重要作用的是位于它两侧的预定肌节。电子显微镜的观察指出,预定脊索和肌节细胞相互靠得很近,或者相隔一定距离,以突起相连形成腔隙。有被小窝和小泡在两类细胞的外缘常被观察到。最引人注意的是在肌节细胞近腔隙的部位或者附近,球状体的出现。它们大小不等,内含物主要是颗粒,有的松散分布,有的致密地充满整个球状体。这些颗粒的大小和电子染色与这时期胚胎细胞中的核糖体很相似。在预定脊索细胞中以及附近,未见上述结构,但是,观察到它们伸出突起包吞腔隙中物质的现象。讨论了这些球状体的出现与脊索决定之间可能存在的关系。During the process of determination, the presumptive notochord is situated beneath neuroepithelium, flanked at two sides by presumptive somites and underlain with archenteron roof ventrally. Among these neighbouring embryonic tissues, presumptive somites were found to exert the main influence on notochord determination. By electron microscopic observations, the presumptive notochord and somite cells were seen to situate either close to each other (plate I, Fig. 1) or connected by cytoplasmic processes forming intercellular lumen (plate I, Fig. 5). Coated pits and coated vesicles appeared at the outer surface of both types of cells (plate I, Figs. 1-4). For the presumptive somite cells, spherical bodies of different sizes and variable contents were observed either near or protruding from the outer surface (plate Ⅱ, Figs. 6-10). The spherical bodies were also found in the intercellular lumen (plate Ⅲ. Fig. 11). These spherical bodies were mainly composed of granules, loosely scattered or densely packed. The granules were of similar size and similar shade of electron staining as those of ribosomes of the presumptive somite cells. For the presumptive notochord cells, no spherical bodies of the above mentioned type were found, but phenomenon of engulfing luminal material was observed (plate 1, Fig. 12). The significance of the appearance of these spherical bodies in the determination of notochord cells has been discussd.

关 键 词：爪蟾 脊索 细胞关系 

分 类 号：Q959.530.5[生物学—动物学]