Cloning humans might be one step closer, with scientists in the US managing to use adult skin cells to produce an embryo clone.
The research, conducted by Oregon Health and Science University and published in Cell, involved the replacement of the nucleus of a normal egg cell with that of a skin cell. This procedure is known as somatic cell nuclear transfer. A few days after this, stem cells were extracted from the embryo.
The stems cells from cloned embryos are used to create tissue genetically identical to the DNA of the patient. This means that procedures like organ transplants could be performed without a risk of rejection.
The researchers are sceptical that the embryos could be developed into viable babies. They did not implant the embryos and said they had no intention of doing so. They said that this technique had been tried on monkeys for years, and never resulted in the birth of a cloned monkey.
The development has reignited debate over the ethics of therapeutic cloning.
Professor of Stem Cell Sciences at the University of Melbourne, Martin Pera, believes the breakthrough will lessen opposition to therapeutic cloning. "I think in general, where we look at the potential for alleviating disease, and when that potential becomes real, then some of the objections I think tend to diminish."