ULTRASTRUCTURAL STUDIES ON THE GOAT OOGENESIS / 解剖学报

ABSTRACT

The cytoplasmic and nuclear changes during the development of goat oocytes were studied with light and electron microscopy. The oocyte development may be divided into 8 stages in accordance with the number and distribution of follicle cells and the size of the follicle. The results indicated that the Golgi complex, mitochondria, smooth endoplasmic reticulum and cortical granules became well developed and they moved into the cortical region as the oocyte development proceeded. In the oocytes in the follicle of 1.5-3mm in diameter, all the mitochondria became hooded and the number and size of fibrillar centers in the nucleolus reached maximum, but the nucleolar compaction still not occured at this stage. By the time when the follicle reached 3.5-5mm in diameter, the follicular cell processes began to degenerate, the microvilli of the oocyte withdrew from the zona pellueida and the oocytes might be cultured to mature in vitro. In the mature oocytes, Golgi complex and rough endoplasmic reticulum disappeared, the cortical granules arranged themselves in one layer beneath the oolemma, the mitochondria dispersed in the central region of cytoplasm and the eggs were ready for fertilization.