Alternative strategies for nuclear reprogramming in somatic cell nuclear transfer (SCNT)

Twenty years passed by since the production of Dolly the sheep, but despite significant technical progress has been achieved in the manipulation procedures, the proportion of offspring following transfer of SCNT embryos has remained almost unchanged in farm animals. Remarkable progress has been obtained instead in laboratory animals, particularly by Japanese Groups, in the mouse. However, the nuclear reprogramming strategies tested in mouse do not always work in farm animals, and others are difficult to be implemented, for require complicated molecular biology tools unavailable yet in large animals. In this review we put in contest the previous work done in farm and laboratory animals with recent achievements obtained in our laboratory, and we also indicate a road map to increase the reliability of SCNT procedures.