Tuesday, March 4, 2014

Power to Rewrite the Code of Life

The dairy industry can use the Crispr immune system to protect important bacteria like Lactobacillus acidophilus, which is widely used in yogurts and dietary supplements, from viruses. Credit Todd Klaenhammer/North Carolina State University
Powerful New Way to Edit DNA

In the late 1980s, scientists at Osaka University in Japan noticed unusual repeated DNA sequences next to a gene they were studying in a common bacterium. They mentioned them in the final paragraph of a paper: “The biological significance of these sequences is not known.”

Now their significance is known, and it has set off a scientific frenzy.

The sequences, it turns out, are part of a sophisticated immune system that bacteria use to fight viruses. And that system, whose very existence was unknown until about seven years ago, may provide scientists with unprecedented power to rewrite the code of life.

In the past year or so, researchers have discovered that the bacterial system can be harnessed to make precise changes to the DNA of humans, as well as other animals and plants.

This means a genome can be edited, much as a writer might change words or fix spelling errors. It allows “customizing the genome of any cell or any species at will,” said Charles Gersbach, an assistant professor of biomedical engineering at Duke University.


The pace of new discoveries and applications is dizzying. “All of this has basically happened in a year,” Dr. David S. Weiss of Emory University said. “It’s incredible.”