Dolly, born in 1996, achieved notoriety by being the first mammal to be cloned from the nucleus of a fully differentiated cell, taken from the udder of an adult sheep. Polly, born a year after Dolly, was not only cloned but was also genetically transformed; that is, she carried an introduced gene that codes the protein factor IX, which is involved in blood clotting, which has huge therapeutic value.
Keywords: Dolly; Polly; cloning; pharming; nuclear transfer; reproductive cloning; therapeutic cloning




