THE BURNSI GENE AS A NUCLEAR MARKER FOR TRANSPLANTATION EXPERIMENTS IN FROGS

Nuclear transplantation in Bombina orientalis and utilization of the Pale mutation as a nuclear marker

The discoglossid frog, Bombina orientalis, displays many characteristics that make it desirable as a laboratory animal. We report here the first successful transplantation of embryonic nuclei into enucleated eggs of this organism. The participation of the grafted nucleus in the development of the transplant embryos was confirmed with the use of a genetic marker, the Pale mutation. Frogs homozygous for this recessive gene are much lighter in appearance than the wild-type animals. The use of this trait in appropriate experiments demonstrated that nuclear transplantation in B. orientalis provides embryos whose nuclei may be reliably interpreted as being derived from the injected nucleus.

Transplantation of pluripotential nuclei from triploid frog tumors

Renal tumors were produced by injection of a cell fraction of a tumor into triploid tadpoles of Rana pipiens before they began feeding. Triploid tumor cells were dissociated and transplanted into activated and enucleated eggs. Pluripotency of the implanted nuclei was evidenced by the formation of swimming triploid tadpoles.