LAUSR

The introduction of cell nuclei into enucleated recipient cells, beyond enucleation, is the most sig- nificant stage of somatic cloning procedure. Microsurgical transfer of somatic nuclei can be an alternative method of clonal nuclear-cytoplasmic hybrid reconstruction towards cell fusion induced in the electric field, not only from the aspect of molecular mechanisms of nuclear chromatin rearrangement, advantageously influencing epigenetic reprogramming and structural remodelling of exogenous genetic material, but also because it was proved in recent studies on pig cloning that the effectiveness of piezo-driven microinjection of ear-derived fibroblast karyoplasts measured by the percentage of oocytes preserving vitality after cell nuclei transplantation operation did not differ significantly from the survival rate (viability) of clonal cybrids reconstituted by an electrofusion method. The intraooplasmic injection system of karyoplasts prepared from cells at G0/G1 or G2/M stages of cell cycle could also increase considerably the total efficiency of somatic cloning technique in pigs and other mammal species.