Nuclear transplantation in amphibia started in 1952. By this is meant, sexually mature cloned frogs can be obtained from the nuclei of embryo cells, differentiating cells, and larval-differentiated cells. Transplanted nuclei are reprogrammed to entirely new patterns of gene expression. In this chapter, the methods used to transplant living nuclei into enucleated eggs ofXenopusare described. A method also is described for transplanting multiple somatic cell nuclei into nonenucleated oocytes, a procedure that achieves reprogramming of gene expression in the absence of cell division.
