How Dolly was cloned: nuclear transfer

Nucleus removed

Nucleus containing DNA extracted

Egg taken from female sheep B

Born to sheep C, the lamb, Dolly, is a clone of sheep A

Egg develops into an embryo, which is placed in the uterus of sheep C

Nucleus and egg fused together

Cell taken from female sheep A

Nucleus removed

Egg taken from female sheep B

Egg develops into an embryo, which is placed in the uterus of sheep C

Nucleus and egg fused together

Nucleus containing DNA extracted

Born to sheep C, the lamb, Dolly, is a clone of sheep A

Cell taken from female sheep A