A survey has been made of over 150 adult frogs which have been obtained by the transplantation of nuclei from endoderm cells of Xenopus laevis donors ranging from late blastulae to swimming tadpoles. Many of the transplant-frogs from donors of all ages were entirely normal, and many of the abnormalities observed were not connected with the condition of the transplanted nuclei. Frogs derived from the nuclei of differentiating cells were more often abnormal than those derived from embryonic cells. Out of 27 frogs derived from nuclei of hatched tadpole gut cells, 7 were sterile. The results demonstrate that at least 30% of blastula nuclei and at least 4% of hatched tadpole gut-cell nuclei contain a complete range of the genetic information necessary for the formation and functioning of a normal adult individual.

Adult frogs derived from the nuclei of single somatic cells