Practice question

Demonstration of genomic equivalence required model where nuclear transplantation technically feasible and embryonic development externally observable. Frogs, particularly Rana pipiens and Xenopus laevis, provided large eggs, simple husbandry, and robust embryonic development ex utero. Their eggs tolerated micromanipulation and enucleation, permitting Briggs, King, and later Gurdon to inject somatic nuclei. Mouse, sheep, guinea pig eggs are small, require implantation, and were not amenable until later mammalian cloning advances. Thus amphibian system pioneered equivalence evidence before extension to mammals, establishing concept that differentiated vertebrate nucleus retains full developmental potential.