CONTEXT

Nuclear transfer is a powerful method that can be used to produce cloned animals and to obtain new sources of multipotential cells from differentiated tissues. Blastocyst embryos can be obtained by transplanting nuclei from amphibian or mammalian cells into enucleated eggs.

The potential ability of this method to deliver supplies of multipotential cells opens new perspectives for cell-based therapies in numerous disorders.  However, nuclear transplantation is often inefficient due to the difficulty of completely reprogramming differentiated adult nuclei for the events of early development. Indeed, identifying the specific epigenetic properties of differentiated cell nuclei represents a challenge of major biological and medical significance.