Changes in an organism’s genome that once took years to make in a lab can now be done in a fraction of the time, thanks to a new method of genome engineering. “This technique allows us to do some amount of rapid evolution” [New Scientist], says lead researcher Harris Wang.
In the experiment, the scientists used a technique called Multiplex Automated Genome Engineering, or MAGE, to program E. coli bacteria to produce five times as much of an antioxidant called lycopene than normal. In addition, using the process, which grafts pieces of synthetic DNA into the genomes of dividing cells, researchers generated 15 billion different genomic patterns in just three days. The process would normally take years, and could eventually be used to produce industrial chemicals, drugs, fuel and anything else that comes out of bacteria [Wired.com]. The process is significantly faster than previous techniques, in which scientists had to modify genes by changing bases one by one, for example, or by cutting genes from one genome and gluing them into another, modifying and inserting them one at a time.
As the researchers describe in a paper in Nature, the MAGE technique allows them to make such changes much more swiftly. It starts with single-stranded pieces of DNA, custom synthesized to fit on target sections of a genome. In a microscopic remix of the famous Dr. Frankenstein movie scene, a target cell is then jolted with energy, opening holes in its membrane [Wired.com]. The DNA flows into the cell, and when it replicates, it creates cells that contain the engineered DNA.
Engineering microbes to produce a certain compound is not new, but until now, it’s proved prohibitively labor-intensive. The American chemicals firm DuPont, for instance, spent nearly seven years and hundreds of millions of dollars to identify 20 genetic changes that optimise microbes to produce a chemical used as a commercial solvent called 1,3-propanediol [New Scientist]. Using MAGE, however, could cost scientists only a few thousand dollars to mutate a gene thousands of times within a few days. That would make it much easier for researchers to create their own custom strain of bacteria.
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Image: flickr / ftoomschb