Gene-Editing Unintentionally Adds Bovine, Goat, and Bacterial DNA, Researchers Find

In Japan, Jonathan Latham reports that researchers have discovered that standard methods of animal and plant gene-editing introduce DNA from unexpected sources. Inadvertently incorporated into the genomes of their edited mouse cells they found DNA from the E.coli genome (a bacterium) and from the cow genome, along with goat DNA.The researchers traced this adventitious presence to contaminants of standard components of the gene-editing process, such as cell culture media. The discovery suggests not only that edited organisms may acquire random foreign DNA, but that present methods of gene-editing can transmit genetic elements, viruses, and other pathogenic agents between species. These findings therefore have very important implications for biosecurity and for the regulation of gene-editing.