Figure 3
Vector integration frequencies in the high incidence regions of the LMO2 and TNIK gene loci. MLV vectors integrated in the HIR of the TNIK (open circles) and LMO2 (closed circles) gene loci were detected by PCR with combinations of MLV vector-specific primers (3' L1L2) and gene-specific primers (F1F2 or R5R6) using extracted DNA samples from MLV-infected cells as template. Our results indicate that 42% of these MLV-infected cells expressed GFP. The number of vector integrations represents the number of detected integrations per 15 PCR amplifications, as calculated by Poisson distribution analyses. Each data set gave straight lines fitted by a linear approximation with a correlation coefficient (TNIK: R2 = 0.978; LMO2: R2 = 0.977). The calculated frequencies, according to each line, were one per 1.992 × 105 cells (TNIK) and 2.125 × 105 cells (LMO2). The frequencies of vector integration into the HIRs of the TNIK and LMO2 genes, which were calculated using data based on Poisson distribution analyses, were one per 4.18 × 104 cells (1.992 × 105 cells (based on Poisson distribution analyses) × 0.42 (% of GFP positive cells)/2 (3' LTR primer direction/3' and 5' LTR primer directions)) and one per 4.46 × 104 cells(2.125 × 105 cells (based on Poisson distribution analyses) × 0.42 (% of GFP positive cells)/2 (3' LTR primer direction/3' and 5' LTR primer directions)), respectively.