The ability to delete specific genes and to replace specific gene sequences by homologous recombination have proven to be powerful tools in fundamental research using bacteria and yeast and in biomedical research with mice. Low rates of targeted gene deletion and editing in crop plants and livestock have limited advances in research and the application of these techniques to agriculture. Within the last few years, new technologies such as zinc finger nucleases (ZFNs) and meganucleases have been developed that have made targeted gene modifications feasible for several plant and animal species. The recent advent of two breakthrough gene-editing technologies, TALENs and CRISPR/Cas9, offer highly efficient and accurate means of gene editing that have been rapidly adopted by researchers. These technologies promise to greatly speed progress toward introduction of crop and livestock genotypes with valuable new traits not achievable in reasonable time frames using conventional breeding techniques. Importantly, the ZFN, meganuclease, TALEN and CRISPR/Cas9 genes responsible for creation of both of targeted gene deletions and improved "replacement" genes can, themselves, be eliminated by conventional breeding to yield plants or livestock that potentially will not be classified as genetically modified organisms (GMOs).
The 2014 NABC meeting on " New DNA-Editing Approaches: Methods, Applications and Policy for Agriculture" will offer a primer to the science behind the new methods for gene modification, provide specific examples of improved crops and livestock that may soon enter the marketplace and address key policy issues underpinning oversight of these potential non-GMOs in the United States, Canada and beyond.