【摘要】 利用透射电镜技术研究了绵羊８－１６细胞胚胎的超微结构，并与２细胞胚胎作了比较．结果表明，８－１６细胞胚胎卵裂球间以间隙连接联系，胞质主要成分是一种带有界膜的囊泡，线粒体丰富，以带帽线粒体为主，也有少量横嵴线粒体，１６细胞胚胎中，后者的比例高于８细胞胚胎．与２细胞胚胎相比，８─１６细胞胚胎的高尔基体发达．但滑面内质网数量减少、８细胞胚胎卵裂球具有数个致密的球形或环形核仁前体，１６细胞胚胎的核仁中出现次级小泡腔，标志着ｒＲＮＡ开始合成．更多还原

【Abstract】 The ultrastructure of 8-16 cell sheep embryos was observed with TEM and compared with that of 2 cell embryos. The cytoplasm of the blastomere in 8-16 cell embryos was characterized by a large quantity of membrane-bounded vesicles and a lot of hooded mitochondria of various shapes. Some transverselycristated mitochondria also existed and their number in 16-cell embryos was greater than that in 8-cell embryos.Compared with 2-cell embryos, the 8-16 cell embryos contained more developed Golgi complexes but fewer smooth endoplasmic reticula.Several ball-shaped or ring-shaped nucleolus precursors were found in the blastomere nucleus of the 8-cell embryos and small secondary vesicles appeared in the nucleolus at 16-cell stage, which indicated the beginning of rRNA synthesis.更多还原