Frequent endonuclease cleavage at off-target locations in vivo

Abstract

Target-site DNA breaks increase recombination frequencies, however, the specificity of the enzymes used to create them remains poorly defined. The location and frequency of off-target cleavage events are especially important when rare-cutting endonucleases are used in clinical settings. Here, we identify noncanonical cleavage sites of I-SceI that are frequently cut in the human genome by localizing adeno-associated virus (AAV) vector-chromosome junctions, demonstrating the importance of in vivo characterization of enzyme cleavage specificity. © The American Society of Gene & Cell Therapy.