An American scientist claims to have made the world's first cloned human embryo and says he will implant it in a surrogate mother later this year.
Dr Panyiotis Zavos, a fertility specialist at the University of Kentucky, also said he had created hybrid embryos by putting human DNA into "emptied" cows' eggs. He insisted that this was not in poor taste but was done as a scientific model for future human cloning efforts.
But the claim met scepticism from other scientists, who pointed out that the work had not been published in scientific journals where others could verify the procedures and data.
He joins a burgeoning group who have claimed to have made cloned embryos or even humans. Dr Severino Antinori and the Raelian cult made separate claims last year but neither has been verified.
Dr Zavos said at a meeting in London yesterday that he created the cloned embryo earlier this year with cells taken from a woman. "We attempted to transfer [implant] it in July but our surrogate [mother] developed complications and we had to postpone," he said. "But we will try again this year." The embryo was at an early stage, where it had only grown to about eight cells, and had been kept frozen - as is commonly done with embryos for test- tube babies - until the surrogate was ready to receive it.
The experiment is being done in a secret location outside the US and Europe, which outlaw human cloning for reproduction. Some sources speculated that Dr Zavos, a Cypriot by birth, may be doing the work in the Middle East or even China. But Dr Jackie O'Connell of Cambridge University expressed doubts over the research and its chances of success if it were true. "The major problem with cloning is that many embryos survive to the blastocyst stage, of 128 cells, but then there's a massive rate of attrition. Most implanted cloned embryos never reach maturity."
Dr Zavos said that the purpose of his cows' egg experiment was to understand the mechanisms of cell developments and cloning methods. "We aren't creating humans by putting DNA into bovine eggs," he said. "We aren't interested in creating monsters."
Dr Zavos said that he chose not to submit his work to the best-known scientific journals, Science and Nature, because he preferred to be published in journals read by reproductive scientists. His latest work on the bovine-human hybrid is to be published in an online peer-reviewed journal called Reproductive Biology Medicine.Reuse content