Production of normal calves after transfer of IVF-derived bovine embryos = 체외수정란 유래의 송아지 생산

Abstract

To verify in vivo viability of I VF-derived bovine embryos, morula and blastocysts that developed from in vitro matured and fertilized ova were transferred to the uteri of recipient cows and normal calves were produced. To produce I VF-derived bovine morula or blastocysts, ova matured and fertilized in vitro were cultrued in culture medium for 7 ？8 days at 39 °C under the humidified atmosphere of 5% CO2. Two different culture systems, a co-culture system with TCM-199 and bovine epithelial cells (BOEC) and CRlaa without somatic cell support, were compared. Cleavage rates to 2？8 cell stage and developmental rates of IVF-derived bovine embryos to blastocyst stage were not different between co-cultrue system (51.3 and 14.0%) and CRlaa medium (60.4 and 22.1%), respectively. Embryos were classified into three grades by embryo quality and then one or two embryos in higher quality (A and B grades) were transferred to the uterus of recipients. In this study Korean Native calf was first born after transfer of I VF-derived embryos. Total four live calves were normally developed to term from IVF-derived bovine blastocysts and one female fetus was stilbborn approximately 8 months of gestation, but there was no pregnancy after transfer of morula. Therfore, normal calves could be produced after transfer of I VF-derived bovine embryos cultured in CRlaa medium without somatic cell support. In addition, our results suggest that in transfer of I VF-derived bovine embryos blastocyst stage is better than morula.