Fig. 2.
Somatic mutations in VH genes during the NP response. Frequency of rearranged VH genes accumulating W33L (red columns) and K58R (yellow columns) substitutions in (A) IgG1 memory and GC B cells in the primary response (day 40) and (B) IgG1 memory B-cell progeny in the secondary response at 1, 3 and 8 weeks after challenge. The ordinate represents the percentage of clones in the total number of VH genes analyzed and the horizontal axis represents the number of mutations accumulated in the VH genes. The blue columns represent the VH genes without accumulation of W33L or K58R and the green columns represent the VH genes carrying both substitutions. The data are illustrated from the analysis of 16–40 VH genes sequenced from spleen (Spl) and bone marrow (BM) of three individual recipients at 1 week (a–c), 3 weeks (d–f) and 8 weeks (g–i) of the response. The data for BM in No. 2 (middle panel) recipient at 1 week of the response are based on analysis of seven VH genes sequenced.