Genomic multipotentiality of differentiated somatic cells.

Nuclear transplantations from several differentiated somatic cell types into amphibian oocytes and eggs revealed that their genome contains the genes required for the development of prefeeding tadpoles. In addition, erythrocyte nuclei directed the formation of feeding tadpoles (independent organisms) that advanced to larval stages with hind limb buds. Thus, the genome of several differentiated somatic cell types can undergo widespread activation and specify a multiplicity of cell types. Although evidence for the genetic totipotency of differentiated somatic cells is lacking, we speculate that the genetic totipotency of at least some differentiated somatic cell types still remains a tenable hypothesis.