WGS analysis of single-cell-derived clones that were gene-corrected using NICER gene editing

In TK6261 cells, harboring compound heterozygous mutations in the TK1 gene, we conducted gene correction for the mutation (c.231dup) in exon 4 of the TK1 gene using the following methods: (1) The NICER technique, which induces homologous recombination between homologous chromosomes using the Cas9 nickase for multiple nicks. (2) The conventional method employing a DNA double-strand break by Cas9 and a DNA repair template (ssODN). Following gene correction, we established single cell-derived clones (SCCs). Additionally, for untreated control, SCCs were established from TK6261 cells that had not undergone genome editing. We conducted whole genome sequencing (WGS) analysis on each SCC. The objective was to analyze the off-target mutation frequency induced by each gene correction method based on the data obtained.