To compensate for the critical shortage of human organs for allotransplantation, xenotransplantation studies using genetically modified pigs are being performed in Korea. Two types of pigs that are used are α1,3-galactosyltransferase gene knockout (GalT KO) pigs and GalT KO+hCD46 (human complement regulatory protein) pigs. The present study measured the gestation time, birth weight, daily growth rate, and heart weight of both kinds of transgenic minipigs. The gestation period for both types of pigs was 117∼119 days. There was no difference in the body weight of GalT KO (—/+) and GalT KO (—/—) piglets, but GalT KO+hCD46 (—hCD46+/+) pigs were significantly heavier at birth than were GalT KO+hCD46 (—hCD46+/—hCD46+) pigs. During the first 10 weeks of life, the daily weight gain of GalT KO+hCD46 (—hCD46+/—CD46+) piglets, which are considered the optimal type for xenotransplantation, was 0.19 kg. The weight of hearts from GalT KO piglets up to two months of age was affected more by body weight than by age. Transgenic pigs showed no differences in gestation period or reproductive ability compared with normal pigs. These results comprise basic data that may be used in xenotransplantation studies and transgenic animal production in Korea.

5‐aza‐2’‐deoxyctidine (5‐aza‐dC) is DNA methylation inhibitor and Trichostatin A (TSA) is histone deacytlase inhibitor, both of them can alter the level of the epigenetic modification of cells. The objective of this study was to investigate the effects of treatment with 5‐aza‐dC and TSA into fetal fibroblasts on the development of porcine nuclear transfer (NT) embryos. In this study, experiments were performed in order to modify epigenetic status in donor cells and evaluate developmental potential of NT embryos. 5‐ aza‐dC or TSA or combining treatment of TSA and 5‐aza‐dC was treated into growing donor cells for 1 h exposure and development of NT embryos was evaluated. Experiment was performed with 3 groups: control group (donor cells without treatment); TSA group (donor cell treated with 50 nM TSA for 1 h); TSA + 5‐aza‐dC group (donor cells were treated with 50 nM TSA and 5 nM 5‐aza‐dC for 1 h); TSA+1/2(5‐aza‐dC) group (donor cells were treated with 50 nM TSA for 1h and subsequently treated with 2.5 nM 5‐aza‐dC for another 1h). When donor cells were individually treated with 5 nM 5‐aza‐dC or 50 nM TSA for 1h, the blastocyst rate of NT embryos increased significantly compared with control group [18.8% vs 13.4% (5 nM 5‐aza‐dC group vs control group), and 26.2% vs 11.8% (50 nM TSA group vs control group), p<0.05]. However, the blastocyst rate in combining treatment group (50 nM TSA + 5 nM 5‐aza‐dC) did not increase compare with control group (12.3% vs 11.8%, p>0.05). When the donor cell were individually treated with 50nM TSA for 1 h firstly and then treated with 2.5 nM 5‐aza‐dC for another 1h, the blastocyst rate was significantly improved compared with control and TSA group (28% vs 10.2% and 23.7%, p<0.05). The present study suggested that donor cells treated with TSA or low concentration of TSA+5‐azadC in short time exposure may enhance the development of porcine NT embryo.