Practice question

Dolly the sheep, born in 1996 at Roslin Institute, demonstrated mammalian somatic cell nuclear transfer could reverse differentiation. Nucleus from quiescent mammary epithelial cell of adult Finn Dorset ewe was fused to enucleated egg from Scottish Blackface ewe. After in vitro activation and implantation into surrogate, Dolly developed as genetic clone of donor. Choice of mammary gland illustrated differentiated adult cell retained full genetic information. Liver, sperm, and egg cells were not used as nuclear donors. Success proved genomic equivalence in mammals and opened regenerative biology and cloning research.