Nearly there

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: Like a striptease artist in front of an eager audience, Craig Venter has been dropping veils over the past few years without ever quite revealing what people are hoping to see: the world’s first artificial organism. He has been discussing making one since 1995, when he worked out the first complete genetic sequence of a natural living organism. And, after a lot of hard graft and blind alleys, he and his team have almost got there. As they report in the Science, they have replicated the genome of Mycoplasma genitalium, the species that was the subject of that original sequencing effort. It is not actual life, but it is surely the tease before the last veil finally falls away.

Though Dr Venter is the public face of the effort, and the 17-strong team that did the work are all employed by the

J Craig Venter Institute in Rockville, Maryland, the synthetic genome project is equally the brainchild of his collaborator, Hamilton Smith. Indeed, it is in Dr Smith’s name that the paper announcing the synthesis is published—along, of course, with the 16 others including Dr Venter himself.

It is a formidable effort. But what is, perhaps, most noteworthy is that the starting point for the project was not the raw nucleotides (the chemical letters of which DNA is composed), but a set of pre-assembled ‘cassettes’ of DNA that the team had ordered from commercial suppliers. The point where any Tom, Dick or Harriet with a reasonably well equipped genetics laboratory could do likewise is not, therefore, that far off. M genitalium’s genome is a single, circular chromosome that is 580,076 letters long, and contains 485 protein-coding genes. The team divided it on paper into 101 units, each containing four or five genes. They also took the precaution of editing one gene in particular, so that it would not work. The gene in question is crucial to M genitalium’s ability to stick to mammalian cells, and thus become infective (it lives naturally in the urinary tract and is thought to cause urethritis). Disrupting it thus forestalled the risk of creating anything nasty.