Craig Venter, an American scientist and pioneer in thedrive to unravel the human genetic blueprint, said his project could have practical benefits but acknowledged that the experiment has serious ethical implications.
He told the American Association for the Advancement of Science, in Los Angeles, that he has asked a body of religious leaders and ethicists to consider the moral implications of making a synthetic organism.
Dr Venter's plans are based on genes taken from Mycoplasma genitalia, a parasite which makes its home in human reproductive organs. It is the simplest life-form yet found, and is made up of just 470 genes, compared to the estimated 80,000 in human DNA.
Research has established that just 300 of the microbe's genes are essential to its existence, although it is unclear what function 100 of these perform.
Now Dr Venter, head of Celera Genomics, wants to synthesise these 300 genes and get them to make their own self-reproducing cells. "We're trying to understand the minimum set of genes necessary to comprise a living cell," he said.
The idea drew a mixed reception from other scientists. "It is technically feasible, and it would be a daring piece of genetic engineering," said Steve Jones, professor of genetics at University College London. "The thing about nature, though, is that it has ways of being more complicated than we think."
Professor Richard Dawkins, author of The Selfish Gene, said: "Synthesising life in a test tube would be a blow to the religious view that there's something special about life. But this is no different in concept from genetic modification of an existing life-form."
However, John Durant, professor of public understanding of science at Imperial College, London, said: "One can see potential benefits, but also potential risks. "This work should be done in a very secure environment, like that for working with dangerous pathogens."
Association reports, page 5