The achievement, thought impossible by most experts, used the type of cloning that has been grist for science-fiction mills for decades. It also sets the stage for possibly cloning human beings, although many technical and ethical hurdles remain before that can become a reality. Plant biologists have always known that it's possible to clone plants from single cells. But this shows now you can do it in animals, including higher mammals like sheep. The successful experiment by Ian Wilmut and colleagues of the Roslin Institute, Edinburgh, Scotland, will be reported in the Thursday issue of the British science journal Nature.
Experts say it has many significant implications.
It also will provide insight into how DNA performs during fertilization, embryonic development and old age. And it will enhance the understanding of how human diseases develop and how to make better drugs to treat them. Scientifically, it's been an extraordinary development. Cloning was believed to be impossible because early experiments with frogs suggested that the DNA of most cells was permanently changed after fertilization and early development. So adult DNA was assumed to be missing the instructions for making a new embryo.