In 1996, Dolly became the first mammal cloned from an adult somatic cell.
Scientists at the Roslin Institute near Edinburgh created Dolly using somatic cell nuclear transfer. They placed the nucleus from an adult Finn Dorset ewe’s mammary-gland cell into an enucleated egg cell taken from a Scottish Blackface ewe. The reconstructed embryo was then implanted into a surrogate Scottish Blackface ewe.
Dolly was born on 5 July 1996 and was publicly announced in February 1997. Her birth demonstrated that genetic material from a differentiated adult cell could be reprogrammed to direct the development of an entire animal. This was a major milestone in developmental biology and cloning research.
Dolly was not the first animal cloned by any method; earlier experiments had cloned embryos and other animals. Her distinction was being the first mammal cloned from an adult somatic cell. She lived at the Roslin Institute, produced six lambs, and died in 2003 at the age of six.