Studies On Germianl Vesicle Chromatin Configuration In Goat Oocyte

Although techniques of in vitro maturation (IVM) of mammalian oocytes have made great progress, some problems are still unsolved. Even though COCs were strictly selected before in vitro culture, the chromatin configuration of dictyate stage oocytes was different. Therefore, oocytes collected from follicles of different diameters in the same ovary were heterogeneous. This is one of the reasons for the poor quality of in vitro matured oocytes. In this study, we observed the changes of germinal vesicle chromatin configuration in goat oocytes from follicles of different diameter and health status, and during in vitro and vivo maturation using fluorescence microscopy.The results are as follows:1. Eight types of GV chromatin configurations were observed with Hoechst 33342 staining in the goat oocytes according to the morphology of chromatin and the size of nucleolus and they were GV0. GVK GV2 (GV2-1, GV2-2), GV3 (GV3-1, GV3-2) GV4 and GVBD.2. Oocytes from the pre-antral follicles were all at GVO stage and oocytes from 0.5-0.8mm follicles were all at GV1 stage. With the follicular development, the proportion of GV3 stage was significantly increased.3. During in vitro maturation, the proportion of GVK GV2 and GV4 declined but the proportion of GV3 and GVBD was significantly increased with time of culture.4. The proportion of GV3 stage oocytes from healthy follicles was significantly higher than that from atretic follicles. The proportion of GV and GVBD stage oocytes from atretic follicles was significantly higher than that from healthy follicles.5. With the increases of follicle diameter, the diameter of nucleoli in oocytes reduced.6. The GV chromatin configuration of oocytes from preovulatory follicles after FSH and hCG injection was mainly at GV3 stage and the proportion of GV3-1 stage oocytes was much higher than that of the GV3-2 stage ones.7. RNA synthesis was intensive in oocyes from follicles of 0.5-0.8mm diameter, became faint in oocytes from follicles of 1-3mm diameter and ceased in oocytes from follicles of >3mm diameter.Candidate: Sui hongshu Specialty: Basic Veterinary ScienceAdvisor: Prof. Tan Jinghe...