Figure 2. LM-PCR assay demonstrates that DSBs in the IgH Sμ region and c-myc gene are not detectably affected by deletion of nth1 and/or or ogg1 genes in splenic B cells induced to undergo CSR.

The upper panel shows Sμ DSBs and the middle panel shows DSBs in the first intron of the c-myc gene in splenic B cells induced to switch to IgG1 for 2 days. Three-fold dose titrations of DNA were assayed (see Methods). The gapdh gene is amplified (lowest panel) as an internal control for template loading. The amounts used for the gapdh assay correspond to the 3 lowest doses of input DNA that were used for the LM-PCR assays. Similar results were obtained in two other experiments for Sμ and one other for c-myc DSBs.