Pseudophysiological transcomplementary activation of reconstructed oocytes as a highly efficient method used for producing nuclear-transferred pig embryos originating from transgenic foetal fibroblast cells

The completely new strategy of pseudophysiological transcomplementary (transcytoplasmic) activation (PP-TCA) of nuclear-transferred oocytes, which had been derived from pWAPhGH-GFPBsd transfected foetal fibroblast cells, was recently applied to the somatic cell cloning of pigs. It resulted in the considerable enhancing not only the cleavage activity of cultured cloned embryos, but also their morula and blastocyst formation rates as compared to the use of standard simultaneous fusion and electrical activation of reconstituted oocytes (77% vs. 57%, 63% vs. 46% and 40% vs. 27%, respectively). Altogether, the use of cytosolic components descended from heterologous (rabbit) zygotes as the agents for stimulation of porcine clonal cytoplasmic hybrids (cybrids) turned out to be reliable and feasible strategy for the generation of transgenic blastocysts by somatic cell nuclear transfer (SCNT). Furthermore, to our knowledge, no previous study has reported the preimplantation developmental outcome of transgenic nuclear-transferred pig embryos following the PP-TCA that was developed and optimised in our laboratory.