Effect of zona pellucida removal on the development of I cloned pig embryos

Abstract

This study aims to evaluate the effect of zona pellucida (ZP) removal on the efficiency of cloned embryos of I pig. For producing I pig cloned embryos, the authors used the oocytes with ZP and with ZP removal. The results showed that the percentage of intact oocytes after enucleation of the group with ZP removal oocytes was 96.19 and 86.28% and of the group with ZP was 83.92 and 82.19%. However, the rates of intact enucleated oocytes among these groups have no statistical significance (86.28 to 82.19% with p>0.05). Enucleated oocytes were implanting somatic cell nuclear transfer, fused, activated by cytochalasin B (7.5 µg/ml), and in vitro cultured in PZM3 medium to evaluate the efficiency of embryogenesis. The cleavage rate and blastocyst formation of the group with ZP removal were higher than those of the group with ZP, 84.98 vs 71.84% and 24.41 vs 16.03% respectively (p<0.05). The results exhibited that ZP removal improved the efficiency of producing cloned embryos of native I pig of Vietnam.