Remaking us in our own image - the cloning debate

Scientists are progressing apace but the successful cloning of humans still looks to be a long way off, writes STEVE CONNOR.

The creation of an embryonic human clone that develops normally and lives for at least 14 days in the laboratory - the legal limit in Britain for "normal" test-tube babies - would rival some of the greatest scientific breakthroughs.

It would mean scientists could harvest the cloned embryo for the all-important stem cells that are seen increasingly as the key to fighting intractable illnesses such as Parkinson's, heart disease and the many disorders of old age. It would also make "virgin birth" a possibility.

The announcement by Advanced Cell Technology (ACT), an American biotechnology company based in Worcester, Massachusetts, that it has created a cloned human embryo that has developed to the six-cell stage is an important step towards a fully viable cloned embryo but it falls short of achieving the goal itself.

ACT, which has a track record in animal cloning, is the first organisation to publish a peer-reviewed paper detailing how its scientists created a human-cloned embryo by transferring the nucleus of an adult cell into the unfertilised human egg that had its own nucleus removed.

But because the embryo did not live beyond the six-cell stage, the company will have difficulty convincing sceptics it has made the breakthrough its publicity machine says has been made.

Other scientists claim to have achieved the same success but because their experiments were not published in a scientific journal they lacked credibility.

But ACT has published its research in the Journal of Regenerative Medicine. Michael West, chief executive of ACT, said the aim of the research was "not to create a cloned baby" but to produce embryonic stem cells capable of mending damaged tissues or organs in what is termed "therapeutic" cloning.

Reproductive cloning, when a cloned embryo is allowed to develop into a baby inside the womb, may not be the goal of ACT and other cloning researchers but it is one possible use of the same technology.

In Britain, the Government believed that the Human Fertilisation and Embryology Act banned anyone attempting human reproductive cloning, but a High Court judge ruled otherwise this month.

The act's definition of an embryo did not cover an embryo created by the transfer of an adult cell nucleus to an unfertilised egg with its own nucleus removed.

The Government is now trying to pass emergency legislation to make it illegal for anyone to transfer an embryonic clone into a womb, but not it seems to cover the export of a cloned embryo to a country where this is not illegal.

Human cloning is controversial but not illegal in America. Unlike in Britain, there is no regulation of private-sector laboratories experimenting with embryos and little likelihood it will be banned in the near future.

US law prevents only the funding of cloning research by the Government leaving the private sector a free hand to carry out research. Moves towards a complete ban have been put on hold by the September 11 attacks as legislators focus on anti-terrorism and economic stimulus packages.

American scientists are nervous about being seen to be involved in anything that smacks of cloning human babies.

"Scientifically, biologically, the entities we are creating are not individuals. They're only cellular life," said Dr West.

This is not the view of the Catholic Church and other "pro-life" groups opposed to human embryo research.

John Smeaton, national director of the Society for the Protection of Unborn Children, said: "This appears to be a disturbing and deplorable development. It underlines the need for the Government's bill to be fundamentally changed so all forms of human cloning are banned."

Other scientists criticised ACT for trumpeting something that was not yet the Holy Grail of human embryonic cloning.

Professor Ian Wilmut, of the Roslin Institute near Edinburgh, who led the team that created Dolly the sheep, said the ACT research was still preliminary.

"Even if you took the nucleus out of an unfertilised egg it would still develop to the six-cell stage under the right conditions without necessarily adding the nucleus of an adult cell. The fact that it did not develop beyond six cells suggests it is fairly lightweight research."

The announcement may have more to do with commercial pressure than scientific achievement, he said.

"In terms of what this says for human cloning, it is pretty irrelevant."

Although scientists had cloned a variety of mammals using the Dolly technique including mice, goats and cows other species, such as dogs, cats and monkeys, have proved a lot harder. Professor Wilmut said cloning human cells might also be difficult.

Jose Cibelli, vice-president of ACT, dismissed suggestions the company was engaged in a publicity stunt.

He said the findings indicated there was no biological barrier to cloning human embryos using the Dolly technique, a method which, in effect, "reprogrammed" a mature, fully specialised skin cell so that it possessed all the developmental potential of a fertilised egg cell.

- INDEPENDENT