Scientists in the United States have succeeded in developing the first living cell to be controlled entirely by synthetic DNA.
The researchers constructed a bacterium's "genetic software" and transplanted it into a host cell.
The advance, published in Science, has been hailed as a scientific landmark, but critics say there are dangers posed by synthetic organisms.
The 大象传媒's Matt McGrath explains.
Craig Venter has been leading the team in Maryland USA.
He and his colleagues are already collaborating with pharmaceutical and fuel companies to design and develop chromosomes for bacteria that could produce useful fuels and new vaccines.
Critics say that the potential benefits of synthetic organisms have been overstated.
Jon Stewart of the 大象传媒 Science in Action programme asked Dr Venter how important he thought this breakthrough was.
The creation of synthetic or artificial life raises ethical questions as well as questions about its safety.
Professor Julian Savulescu is the director of the Centre for Practical Ethics at Oxford University.
First broadcast 20 May 2010