Kinetics of reprogramming in cell fusion hybrids

Somatic cells can obtain pluripotency by fusion with pluripotent stem cells. The resulting fusion hybrids display pluripotential characteristics, such as inactivation of tissue-specific genes, differentiation potential to all three germ layers, and a specific epigenetic state corresponding to the pluripotent cells. However, the fusion hybrid cells are not identical to the pluripotent fusion partner cells although they are similar to the pluripotent cells. Recently, we showed that fusion-induced reprogramming was not a solely unidirectional process. In this review, we address how much somatic cells "remember and lose" their original characteristics after fusion with pluripotent cells.