Scientists unveil Dolly, the cloned sheep
On this day · 22 February 1997
On this day in 1997, a Scottish lab introduced the world to a lamb grown from a single adult cell.
On 22 February 1997, the Roslin Institute near Edinburgh introduced Dolly, a Finn-Dorset ewe and the first mammal ever cloned from an adult body cell. The world’s press promptly descended on a quiet research farm to photograph a sheep.
The trick was somatic cell nuclear transfer: scientists took the nucleus from a single mammary-gland cell, slipped it into an egg emptied of its own DNA, and coaxed the result into an embryo. It was painstaking and rarely worked.
It took 276 failed attempts before Dolly was born on 5 July 1996.
Her keepers kept the breakthrough quiet for seven months, waiting on a paper in the journal Nature. Dolly proved that a specialized adult cell could be reset to build an entire animal, upending a long-held assumption and igniting decades of debate over cloning, stem cells, and where the line should sit.
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