체외배양기술로 생산된 초기배에 의한 한우 송아지 생산기술 III. 배반포와 발생에 미치는 발생배지의 효과와 동결융해후의 생존율에 미치는 Sucrose와 Trehalose의 효과

Development of Production Techniques for Korean Native Cattle Calves from Embryos by In Vitro Technology 3. Effects of Culture Medium on Blastocyst Development and Effects of Sucrose and Trehalose on the Survival Rate of In Vitro Developed Embryos after Thawing

The objective of this study was to evaluate the embryonic development ability and the appearance of blastocysts of bovine in vitro fertilized oocytes cultured in different culture media, and also to evaluate survival rate after thawing of frozen embryos by using 1.5 or 1.8M ethylene glycol(EG) with sucrose or trehalose. Fertilized oocytes were divided into three groups; i ) monolayer of cumulus /granulosa cell prepared by TGM 199+5% calf serum(TGM199), ii)GRlaa+5% CS, iii)SOF+5% CS, and they were cultured after insemination for 9 days, at 39˚C, under 5% $CO_2$ in air, but SOF+5% CS was cultured at 39˚C, under 5% 02, 5% GO2, 99% N2. Blastocysts derived from GRlaa + 5% CS on day 7~8 after insemination were frozen by using 1.5M EG or 1.8M EG with/without 0.2M sucrose or O.1M trehalose. The development rate of blastocysts on day 7 after insemination in SOF+5% CS was significant higher than in TCM199 or CR1aa(P<0.05). The appearance rate of blastocysts on day 7-8 after insemination was higher than in TCM199, when fertilized oocytes were cultured in GRlas or SOF. The survival rate of frozen blastocysts after thawing tended to increase, when blastocysts were frozen by using 1.8M EG with 0.2M sucrose or O.1M trehalose. These results indicated that SOF or CRlaa media with amino acids was superior to TCM199 with monolayer in terms of blastocyst development in culturing of in vitro fertilized bovine nocytes, and sucrose or trehalose was supposed to prevent embryos from the freezing shock.