Genome made quickly from scratch.

Scientists have found a way to rapidly synthesize the entire genome of a virus. To construct the sequence, which consists of 5,386 DNA building blocks, or base pairs, strung into a single chromosome, J. Craig Venter of the Institute for Biological Energy Alternatives in Rockville, Md., and his colleagues first ordered 259 smaller segments of the genome from a commercial supplier.

Using a cocktail of enzymes and extra DNA pieces, the scientists bound the snippets together and filled in gaps. This created a full-length, synthetic version of the chromosome for a virus known as bacteriophage phiX174, which is harmless to people.

The researchers then infected bacteria with their synthetic bacteriophage genome. Although most of the viruses contained errors, some were able to multiply within the bacteria as effectively as their natural counterparts do. Venter and his coworkers announced their findings at a press conference in Washington, D.C., on Nov. 13 and will publish them in an upcoming Proceedings of the National Academy of Sciences.

Last year, scientists announced that they had synthesized the poliovirus genome. That accomplishment took 3 years (SN: 7/13/02, p. 22), whereas it took Venter's team only 14 days to replicate the bacteriophage genome.

The next step, says Venter, is to synthesize the shortest-possible functional microbial genome. A microbe made in this way could potentially consume pollutants or churn out hydrogen for fuel cells, the scientists say. At the press conference, they acknowledged that this technique could be combined with others to create harmful viruses such as smallpox.