Developmental potential of cloned embryos is related closely to epigenetic modification of somatic cell genome. The present study was to investigate the effects of applying histone deacetylation inhibitor, trichostatin A (TSA) to activated porcine embryos on subsequent development of porcine parthenogenetic and nuclear transfer embryos. Electrically activated oocytes were treated with 5 nM TSA for different exposure times (0, 1, 2 and 4 hr) and then the activated embryos were cultured for 7 days. The reconstructed embryos were treated with different concentrations of 0, 5, 10 and 25 nM TSA for 1 hr. Also 5 nM TSA was tested with different exposure times of 0, 0.5, 1, 2 and 4 hr. And fetal fibroblast cells were treated with 50 nM TSA for 1, 2 or 4 hr and with 5 nM TSA for 1 hr. Cumulus-free oocytes were enucleated and reconstructed by TSA-treated donor cells and electrically fused and cultured for 6 days. In parthenogenetic activation experiments, 5 nM TSA treatment for 1 hr significantly improved the percentage of blastocyst developmental rates than the other groups. Total cell number of blastocysts in 1 hr group was significantly higher than other groups or control. Similarly, blastocyst developmental rates of porcine NT embryos following 5 nM TSA treatment for 1 hr were highest. And the reconstructed embryos from donor cells treated by 50 nM TSA for 1 hr improved the percentage of blastocyst developmental rates than the control group. In conclusion, TSA treatment could improve the subsequent blastocyst development of porcine parthenogenetic and nuclear transfer embryos.

ABSTRACT  
 INTRODUCTION   
MATERIALS AND METHODS    
Preparation of Porcine Fetal Fibroblasts    
Preparation of Oocytes    
Parthenogenetic Activation of Porcine Oocytes    
Nuclear Transfer and Fusion    
TSA Treatment    
Western Blot Analysis    
Experimental Design    
Statistical Analysis   
RESULTS    
Effects of TSA Exposure Times on In Vitro Parthenogenetic Pevelopment of Porcine Oocytes
Effects of TSA Treatments on the Levels of Histone H3 Aceltylation of Fetal Fibroblast Cells    
Effects of TSA Treatments on the Development of PorcineNuclear Transfer Embryos Cultured In VitrEffects of TSA Treatments on the Development of Porcine Nuclear Transfer Embryos Cultured In Vitroo   
DISCUSSION   
REFERENCES

• Yun-Fei Diao(Research Center for Transgenic and Cloned Pigs, Chungnam National University)
• Naruse Kenji(Research Center for Transgenic and Cloned Pigs, Chungnam National University)
• Rong-Xun Han(Research Center for Transgenic and Cloned Pigs, Chungnam National University)
• Tao-Lin(Research Center for Transgenic and Cloned Pigs, Chungnam National University)
• Reza-K. Oqani(Research Center for Transgenic and Cloned Pigs, Chungnam National University)
• Jung-Won Kang(Research Center for Transgenic and Cloned Pigs, Chungnam National University)
• Dong-Il Jin(Research Center for Transgenic and Cloned Pigs, Chungnam National University) Corresponding author