Abstract

In 1996, a single lamb born (Dolly) from an experiment involving 277 embryo reconstructions that developed into 29 early in vitro embryos that were transferred into 13 surrogate females, demonstrated that adult somatic cells can have nuclear developmental equivalence to the germ cell lineage. Dolly was the first mammal produced by the transfer of an adult somatic cell nucleus into an enucleated egg and improved the understanding of cellular reprogramming. Many thousands of cloned offspring demonstrate that animal cloning is consistent and adaptable to a wide variety of species. Pluripotent stem cell technologies have not superseded cloning in any livestock species. The advent of precise gene editing of donor cells used for animal cloning has renewed interest in the epigenetics, mitochondrial heteroplasmy and gene expression changes involved in nuclear reprogramming and normal development of the conceptus. Public perception of animal cloning, while initially negative, is starting to change, when the technology is seen to benefit the animal. Collectively, this implies that animal cloning will continue to offer solutions to a wide range of global challenges surrounding improved quality of food, animal models and pharmaceuticals for medical care and species conservation under a much wider public dialogue and bioethical systems review.