Expression of enhanced green fluorescent protein (EGFP) and neomycin resistant (Neo(R)) genes in porcine embryos following nuclear transfer with porcine fetal fibroblasts transfected by retrovirus vector.

In this study, we demonstrated expression of enhanced green fluorescent protein (EGFP) and neomycin resistant (Neo(R)) genes in porcine embryos following nuclear transfer from porcine fetal fibroblasts (PFFs) transduced with the EGFP and Neo(R) genes by retrovirus-mediated infection. Nuclear transfer of the nonstarved transfected PFF into enucleated oocytes was accomplished by cell to cell fusion. Out of 188 porcine eggs reconstructed by nuclear transfer, 116 (61.7%) eggs cleaved and 25 (13.3%) developed to morula and blastocyst stages. Of these 25 morulae and blastocysts, 25 (100%) embryos emitted green fluorescence. Expression of the both EGFP and Neo(R) genes was detected as early as the 2-cell stage. As determined by EGFP gene expression, mosaicism was not observed in any embryo. These results suggest that porcine oocytes reconstructed by nuclear transfer with transfected PFFs can successfully develop to the blastocyst stage. In addition, this approach might be applicable to the production of transgenic pigs with complex genetic modifications.