Abstract: Modeling human disease in cultured cells requires efficient modification of one or both alleles depending on dominant or recessive inheritance. Editing of single nucleotide variants (SNVs) is particularly challenging because the modified allele contains only one mismatch relative to the target sequence and is subject to re-cleavage and damage by the nuclease. The donor nucleic acids provided herein are, inter alia, useful for editing genome sequences by introducing precise changes in a target site in the presence of the donor sequence and minimizing re-cleavage of the donor nucleic acid by nucleases. By doing so, the compositions and methods provided herein produce modified genomic sequences resistant to nuclease cleavage.

Abstract: The invention relates to a nucleic acid construct for bi-allelic conditional modification of a target gene and methods of use thereof.