2012

Jennifer Doudna and colleagues at Berkeley demonstrate that CRISPR-Cas9 (clustered repeated sequences), with which bacteria cells destroy viruses, can be modified in laboratory to destroy genes other than the bacteriophages (bacteria-eating viruses) targeted by the immune systems of specific bacteria. The critical experiment, devised by Martin Jimek and Doudna, targeted a jellyfish gene (green fluorescent protein [ GFP]), incubating them with Cas9 and the jellyfish DNA in a DNA-cleavage assay. The experiment was successful, as all the GFP DNA was sliced apart at the intended site. “How incredible that bacteria had found a way to program a warrior protein to seek and destroy viral DNA! And how miraculous, how fortunate, that we could repurpose this fundamental property for an entirely different use.” Their seminal paper was published in Science on 28 June 2012 The paper concluded “with a brief but significant nod to uses of CRISPR outside of bacteria, including in other cell types”(Doudna & Sternberg, 80-85, quoted at 84, 85).