Biologists have replaced parts of the E. coli bacterium DNA using a new process that hits many targets at once, a feat that may enable scientists to significantly alter or re-engineer genetic material.
A research team, led by Farren Isaacs and George Church of Harvard University Medical School, was able to make precise changes to the cell’s protein-making process in 32 strains of E. coli. They replaced one three-letter sequence of nucleotides with another throughout the entire organism, without harming the bacterium.
Although genetic engineers can change one gene in a genome, this is the first time that as many as 314 sites were altered at once, the authors wrote. The method may allow for making larger- scale changes to DNA, which would be helpful if scientists wanted to make many alterations, they wrote in an article published today in the journal Science.
“Our methods treat the chromosome as both an editable and evolvable template, permitting the exploration of vast genetic landscapes,” the authors wrote.
The technology, known as multiplex automated genetic engineering, or MAGE, was created by Church, Isaacs, and others in Church’s group. It can induce gene alterations in a population of bacteria almost simultaneously, creating billions of cellular mutations in a matter of days.
Church helped to start the government-funded Human Genome Project, which decoded the entire human genetic blueprint in 2000. The public project competed with a private effort by J. Craig Venter, who runs the J. Craig Venter Institute, based in Rockville, Maryland. The teams shared credit for the milestone.
Venter in 2007 replaced the genetic structure of one bacterium with the DNA of a second, transforming one species into another. The emerging field of synthetic biology allows scientists to create organisms that don’t exist in nature. These novel designer microbes may allow for new biofuels and foods, scientists say.
Unlike Venter’s discovery, the Harvard team modified DNA directly in live cells, tricking them into thinking it’s their own.
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