To build a giant sheep, man spends 10 years smuggling, cloning, and inseminating

Enlarge / A male argali sheep in the wild. (credit: Getty Images)

Readers of a certain age might remember Dolly, a Finn-Dorset sheep born in 1996 to three mothers and some proud Scottish scientists. Dolly generated global headlines just by being alive, as she was the first mammal to be cloned using DNA taken from body (somatic) cells.

In this form of cloning, a somatic cell provides the cloned animal's complete DNA, which is then injected into an unfertilized egg cell that has had its existing genetic material removed. Zap the egg with a bit of current, implant it into the womb of a surrogate mother, wait a few months, and bam—out pops Dolly.

The process proved that the magic of embryonic development wasn't hidden only in eggs and sperm; even somatic cells from mature animals were capable of reproducing the whole creature and of generating any cell needed by the developing embryo.