This study was conducted to investigate an effective recipient oocyte and culture system for producing of Hanwoo (Korean native cattle) somatic cell nuclear transfer (SCNT) embryos. Hanwoo ear skin fibroblasts were used as donor cells. In vitro matured Hanwoo or Holstein oocytes were enucleated, and single donor cells were transferred into the perivitelline space of the enucleated oocytes. The couplets were subsequently fused and activated. The reconstructed embryos were cultured in a conventional or sequential culture system. In the former, embryos were cultured in CR2aa medium for eight days; in the latter, embryos were cultured in modified CR2aa-A (mCR2-A) for three days and then further cultured in modified CR2aa-B (mCR2-B) for five days. In the experiment with the recipient oocyte, the rate of embryo development to the blastocyst stage was significantly (p<0.05) higher in Hanwoo recipient oocytes than in Holstein ones (48.8% vs 38.9%). BIastocysts derived from Hanwoo recipient oocytes contained significantly (p<0.05) higher numbers of total cells than those derived from Holstein recipient oocytes (156.0+-68.2 vs 134.7+-54.8)). There was no difference in the mean proportion of apoptotic cells in blastocysts between the sources of recipient oocytes. In the experiment with the embryo culture system, the blastocyst rate was somewhat higher in sequential system than in conventional system (50.0% vs 43.5%), though there was no significant difference. The numbers of total (160.0+-69.0 vs 156.7+-68.4) and apoptotic cells (14.0+-10.4 vs 11.8+-6.4)) were not different between the culture systems. In conclusion, the present study demonstrated that Hanwoo recipient oocytes and the sequential culture system were more effective in supporting the production of Hanwoo SCNT embryos.

본 연구에서는 TCM-199, mSOF, NCSU-23 세 종류의 배지의 자연 단위 발생 유도로 형성된 돼지 배아의 초기 발육에 대한 효과를 조사하였다. 실험 1에서는 세 종류의 배지에서 체외 성숙된 도축장 유래 돼지 난자의 성숙율을 성숙 48 시간째 핵상 관찰로 조사하였다. 각 배지에서의 핵 성숙율은 mSOF군에서 83.12%, NCSU-23 군에서 78.03%, TCM-199군에서 83.52%로 세 배지의 난자 성숙율에 대한 유의적 차이는 없었다(P