牛卵母细胞发育的超微结构研究

本实验根据卵细胞的数量及分布、透明带的变化,卵泡大小等把牛卵母细胞的整个发育过程分为六个阶段,在超微结构的水平上进行了研究。随着卵母细胞的发育,高尔基体、线粒体、滑面内质网、皮质颗粒等细胞器数量不断增加,且逐渐迁移到皮质区。卵母细胞成熟时。高尔基体及粗面内质网消失,皮质颗粒开始在质膜下呈线状排列,而线粒体又向胞质中央区扩散。直径2毫米以上卵泡卵母细胞中,少嵴圆形线粒体一律转变为带帽线粒体,核仁发生致密化。此外,牛卵母细胞中有带有界膜的、均匀分布的囊泡。皮质颗粒成团发生和分布也是牛卵母细胞的特点之一。实验事实证明,皮质颗粒的形成与滑面内质网关系更为密切。

STUDY ON ULTRASTRUCTURE OF BOVINE OOCYTE DEVELOPMENT

Ultrastructural changes during bovine oocyte development were studied with a transmission electron microscope. The development was divided into six stages according to the number and distribution of follicle cells, the change of zona pellucida and the size of follicles. The results indicated that the number of Golgi complex, mitochondria, smooth endoplasmic reticulum and cortical granules (CGS) increased and all organelles moved to the cortical region with the oocyte development. In mature oocytes, Golgi complex and rough endoplasmic reticulum dissapeared, CGS began to arrange themselves in line beneath the oolemma, and mitochondria dispersed toward the central region of cytoplasm. In oocytes within the follicles of more than 2mm in diameter, almost all the round mitochondria with rare cristae turned into hooded ones, and nucleolus compaction occured. In addition, a kind of membrane-bounded, evenly-distributed vesicles existed in bovine oocytes. The CGS developed and arranged in clusters was also a characteristic of bovine oocyte. Many experimental facts proved that the development of CGS was more closely connected to smooth endoplasmic reticulum than Golgi complex.