The Crispr Quandary

10. November 2015

Date: 10-11-2015
Source: The New York Times

A new gene-editing tool might create an ethical morass
— or it might make revising nature seem natural.

Gene EditingOne day in March 2011, Emmanuelle Charpentier, a geneticist who was studying flesh-eating bacteria, approached Jennifer Doudna, an award-winning scientist, at a microbiology conference in Puerto Rico. Charpentier, a more junior researcher, hoped to persuade Doudna, the head of a formidably large lab at the University of California, Berkeley, to collaborate. While walking the cobblestone streets of Old San Juan, the two women fell to talking. Charpentier had recently grown interested in a particular gene, known as Crispr, that seemed to help flesh-eating bacteria fight off invasive viruses. By understanding that gene, as well as the protein that enabled it, called Cas9, Charpentier hoped to find a way to cure patients infected with the bacteria by stripping it of its protective immune system.

Among scientists, Doudna is known for her painstaking attention to detail, which she often harnesses to solve problems that other researchers have dismissed as intractable. Charpentier, who is French but works in Sweden and Germany, is livelier and more excitable. But as the pair began discussing the details of the experiment, they quickly hit it off. ‘‘I really liked Emmanuelle,’’ Doudna says. ‘‘I liked her intensity. I can get that way, too, when I’m really focused on a problem. It made me feel that she was a like-minded person.’’

At the time, bacteria were thought to have only a rudimentary immune system, which simply attacked anything unfamiliar on sight. But researchers speculated that Crispr, which stored fragments of virus DNA in serial compartments, might actually be part of a human-style immune system: one that keeps records of past diseases in order to repel them when they reappear. ‘‘That was what was so intriguing,’’ Doudna says. ‘‘What if bacteria have a way to keep track of previous infections, like people do? It was this radical idea.’’ Read the rest of this entry »