Fig. 2: SSA-mediated DNA integration is tolerant to sequence divergence and is suppressed by Msh2.

a Schematic representation of HPRT targeting vectors with different arm sequence homology. Shown are 12 targeting vectors with a total arm length of 3.0 kb containing a 1.7-kb 5’ arm with 100% or 95% homology to the genome (intron 2) and a 1.3-kb 3’ arm with 100%, 99%, 97.5%, 95%, 90%, or 80% homology to the genome (intron 3). The wavy lines indicate the plasmid backbone. b Impact of arm sequence divergence on TI frequency. Msh2-deficient (-) and proficient (+) Nalm-6 cells were transfected with vectors shown in (a). Each graph shows TI frequencies of divergent vectors relative to the 100-100 vector p3.0HPRT-2A-Puro (top) or the 95-100 vector (bottom). Where absent, error bars fall within symbols. c Impact of Msh2 deficiency on TI frequency in wild-type (WT) and RAD54^–/–RAD54B^–/– cells. After transfection of linearized p3.0HPRT-2A-Puro (100-100) or p3.0HPRT-2A-Puro-95-95 (95-95), cells were treated with DOPA or B02 prior to replating. Symbols are as in Fig. 1c. Data shown are the mean ± s.d. (n = 3). d Schematic representation of HPRT targeting vectors with a total arm length of 8.9 kb. Symbols are as in (a). e Impact of Msh2 deficiency on TI frequency. Msh2-deficient (-) and proficient (+) cell lines from Nalm-6 and HT1080 were transfected with vectors shown in d, and treated with DOPA or B02 prior to replating. Symbols are as in Fig. 1c. Data shown are the mean ± s.d. (n = 3). f Impact of Msh2 deficiency on gene targeting in LIG4^–/–POLQ^–/– cells. p8.9HPRT-2A-Puro or p8.9HPRT-2A-Puro-95-95 transfected cells were treated with DOPA or B02 prior to replating. Symbols are as in Fig. 1c. Data shown are the mean ± s.d. (n = 3). Statistical significance in (b, c, e, and f) was determined by two-sided Student’s t test. *P < 0.05; **P < 0.01; ***P < 0.001; NS, not significant. Source data are provided as a Source Data file.