METHODS AND COMPOSITIONS FOR ENHANCED NUCLEASE-MEDIATED GENOME MODIFICATION AND REDUCED OFF-TARGET SITE EFFECTS

摘要

Compositions and methods are provided for editing nucleotides or altering target sites in the genome of a cell. The methods and compositions employ a guide RNA/Cas endonuclease system and at least one component selected from the group consisting of (i) an inhibitor of end joining (NHEJ), (ii) an activator of homology-directed repair (HDR) or (iii) any one combination of (i) and (ii), to provide an effective system for editing nucleotides or altering target sites within the genome of a cell. The present disclosure also describes methods for editing a nucleotide sequence in the genome of a microbial cell employing a guide RNA/Cas endonuclease system and at least one component selected from the group consisting of (i) an inhibitor of NHEJ, (ii) an activator of HDR, or (iii) any one combination of (i) and (ii), wherein said microbial cell has reduced or no off-target site effects.