Cloning Dolly by nuclear transfer

  1. The nuclei are removed from a mammary cell of a female lamb and an egg cell from a different female.

  2. The nucleus from the mammary cell is implanted into the egg cell.

  3. An electric shock is applied to the egg to trigger cell division, which can happen in culture for a few divisions.

  4. The embryo is implanted into a living uterus; a 3rd lamb serves as the surrogate mother.

  5. The cloned Dolly is identical in genetic makeup to the mammary cell donor.