Study On The Goat Oocytes' Micro-fertilization (ICSI) And Early Embryo Culture In Vitro

This study was conducted to investigate the goat occytes' micro-fertilization(intracytoplasmic sperm injection, ICSI) and early embryo development in differentculture medias. The results wen, the following:After ICSI, the cleavage rate of the mature oocytes (M II) from in vitro maturation orsuper ovulation in 2-cell, 4-cell, and 8-cell were 34.8% and 34.6%, 21.7% and 19.2%,12.5% and 15.4% respectively. Statistic analysis showed no significant differencebetween the two groups.During ICSI, the cleavage rate of the oocytes treated with cytochalasin B (CB) wasremarkably higher than that of the untreated ones.When sperm and exogenous gene (AI) were injected into oocytes, the following 2-cellcleavage rate was 18.5%, significantly lower than the group injected with sperm only.But in 4-cell, 8-cell cleavage rate, there was no notable difference between the twogroups. Compared with the sham injection group (0), the cleavage rate was much higherin the sperm injection group (34.7%).When the embryos were cultured in the media with 0%( I ), 20%( II), 50%(III).100%(IV) oviduct fluid, the cleavage rate of Group II was 83.3%, 69.0% and 47.6%respectively in 2-cell, 4-cell, and 8-cell. Group II showed no significant differencecompared with Group I ,but much higher than Group III and Group IV. When theembryos developed from 8-cell to 16-cell and morula, Group II was much higher thanother groups, reaching 28.5% and 26.1% respectively.After the injection of exogenous gene, pronuclei embryos were cultured in 0%(control group), 20% and 50% tubal fluid media. There were no significant differences between the cleavage rates of the control group and the group containing 20% oviduct fluid. The cleavage rates in 2-cell, 4-cell, 8-cell of 0% and 20% oviduct fluid group were 86.7% vs. 80.0%, 53.3% vs. 47.5%, 26.7% vs. 32.5% respectively, both much higher than the 50% oviduct fluid group. But in 16-cell, the cleavage rate of 20% oviduct fluid group was 20. 0%, significantly higher than other groups.Compared with those cultured in vivo for 4 days, the cleavage rates of the transgenic cloned embryos cultured in 20% oviduct fluid media in 2-cell, 4-cell, 8-cell, 16-cell. and morula were 68.3%vs. 72.2%, 51.2% vs. 51.2% vs. 58.2%, 41.5%vs. 44.4%, 22.0% vs. 25.0%, 7.3vs 11.1% respectively. Though the embryo development rates cultured in vivo were higher than the ones cultured in vitro, they differed insignificantly. When transgenic embryos co-cultured with oviduct epithelial cell, the cleavage rates in 2-cell and 4-cell were 87.5% and 58.3%. Compared with the control group, no significant difference was found. 58.3% and 37.5% cleavage rates in 8-cell and 16-cell were obtained respectively, which were significantly higher than the control.