The Cloning of Mice

The cloning of mice is done by a different method than that used to produce Dolly. The donor diploid nucleus is from a Cumulus cell that is naturally in the Go stage of the mitotic cell cycle (no starvation of the cells is needed). The host unfertilized egg is ennucleated. The donor nucleus is transferred by microinjection pipet from the cumulus cell to the egg cytoplasm. Egg proteins "re-program" the chromosomes in the nucleus. Then the egg is artificially activated and the dividing embryo is implanted into the uterus of a surrogate mother mouse.

Courtesy of Library Advanced Orginization.