Effect of Donor Cell Types and Passages on Preimplantation Development and Apoptosis in Porcine Cloned Embryos

In this study, two cell types from porcine females, namely fetal fibroblasts (pFFs) and adult ear fibroblasts (pAEFs) and two passages (3-4 and 7-8) were investigated by evaluating the development rate, blastocyst cell number and the incidence of apoptosis. No significant differences were observed in the cleavage rates of cloned and IVF embryos. The blastocyst rates between the embryos cloned with pFFs ($15.1{\pm}3.2$) and pAEFs ($10.4{\pm}2.6$) did not differ significantly but was significantly (p<0.05) lower in pAEFs than that in IVF ($22.5{\pm}4.5$) embryos. Total cell number in pFFs ($28.4{\pm}4.3$) and pAEFs cloned blastocysts ($24.2{\pm}5.1$) was significantly (p<0.05) lesser than IVF control ($35.4{\pm}3.2$). Apoptosis rates between cloned blastocysts differed significantly (p<0.05) and were significantly (p<0.05) higher than IVF embryos. The blastocyst rates between the cloned embryos cloned with different cell passages did not differ significantly but in embryos cloned with 7-8 cell passage was significantly (p<0.05) lower than the IVF control. Apoptosis signals were detected in IVF and cloned embryos as early as day 3 and the rates of apoptosis increased concurrently with the embryo development. In conclusion, high apoptosis during in vitro preimplantation development resulted in low development rate and total cell number of cloned embryos. Moreover, based on the apoptotic incidence in cloned blastocysts, fetal fibroblasts are more suitable for production of cloned embryos in porcine.