Synthetic Biology Takes A Step Forward

Genetic researchers have created the first cell controlled by a synthetic genome, an advance they say could lead to the building of bacteria with customized functions.

J. Craig Venter, whose work helped map the human genome in 2000, and coworkers synthesized the genome of the bacteria Mycoplasma mycoides and then transplanted it to a host cell, in this case Mycoplasma capricolum. The group reports the feat in Science (DOI: 10.1126/science.1190719).

The team at the J. Craig Venter Institutes in Rockville, Md., and San Diego combined several procedures that it helped develop in recent years to grow the bacterial DNA in yeast and then transplant it.

The synthesized genome has four "watermarks" to differentiate it from the natural one. The created cells look and act like normal M. mycoides bacteria and can continuously self-replicate.

"The approach we have developed should be applicable to the synthesis and transplantation of more novel genomes as genome design progresses," the researchers note in the paper.

The team's synthetic genome is more than 1 million base pairs in length, the largest chemically defined structure ever built in a lab, according to the group. The genome is more than 30 times larger than any reported DNA sequence synthesized outside the group's lab.

This work could open the possibility to reengineer an organism according to tailor-made specifications and could be used to better understand the function of every gene in a cell, the research team says.

"It extends the possibility of synthesizing functional, large biomolecules," says James J. Collins, director of the Center for BioDynamics at Boston University.

The group says the technology could be used to design bacteria that create biofuels or sequester carbon dioxide, build industrial compounds, or produce pharmaceuticals including vaccines.

Some scientists say this work isn't creating artificial life because the genome is based on something in nature and not made from scratch.

"This is significant work, though of course it does not mean that scientists can now synthesize life, a common misinterpretation of the field of genome synthesis and transplantation," says David R. Liu, professor of chemistry and chemical biology at Harvard University.