Roles of Calmodulin-dependent Protein Kinase Ⅱ in Meiotic Maturation and Fertilization of Oocytes / 生物化学与生物物理进展

Calmodulin-dependent protein kinase (CaMK), activated by auto-phosphorylation at the presence of calcium and calmodulin, is widely distributed in eukaryotes. CaMKs are important mediators of calcium signal in eukaryotes. Recent researches have suggested that CaMKⅡ is involved in the regulation of meiotic cell cycle of oocytes. It plays functional roles in meiotic maturation, polar body extrusion, fertilization and egg activation. As one of the down-stream signaling molecules of calcium, CaMKⅡ facilitates the inactivation of maturation promoting factor (MPF) and cytostatic factor (CSF) following fertilization, as well as the spindle microtubule organization and centrosome duplication. Although the functions of CaMKⅡ in oocyte meiosis are versatile and essential, the present results are primarily obtained from low vertebrates and mouse. In future studies, the function and regulation of this kinase in other mammals should be stressed.

INTEGRIN ?1 MAY PLAY IMPORTANT ROLE IN HUMAN EGG FERTILIZATION AND EARLY EMBRYO DEVELOPMENT:A CONFOCAL MICROSCOPY STUDY / 解剖学报

Objective To investigate distribution of integrain ?1 in human oocytes and embryos before and after maturation/fertilization,dring the first and second meiosis,in morulae and blastocyst stage. Methods Human oocytes and embryos were stained by anti-integrin ?1 (PharMingen 09351D) and FITC-labeled second antibody (PharMingen 110094D),and observed by confocal microscope. Results Integrin ?1 concentrated in the nuclear area in matured oocytes,zygotes and 2-cell stage embryo,indicating that integrin ?1 might involve in mitosis.Dislike mouse,there was no distribution of integrin ?1 on the well-accepted sperm binding area on the oocytes,indicating that integrin ?1 might not involve in the binding and fusion of human sperm to human oocytes.Conclusion It was first postulated that integrin ?1 might actively involve in the pronuclear fusion process in human in vitro fertilized oocytes.The marker of ectotrophoblasts,polarized distribution of integrin ?1, appeared at the morulae stage.The stronger expression in ectotrophoblasts around the inner cell mass might indicate some specific function of the ectotrophoblasts near the ICM.

ULTRASTRUCTURAL STUDIES ON THE GOAT OOGENESIS / 解剖学报

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.