Distribution of VH gene somatic mutation in IL-21−/− and IL-21R−/− memory B cells
| Genotype | VH186.2− | VH186.2+a | Unmutated | Position 33 mutationb | VH mutation frequency | Excluding germline sequences | |
| Position 33 W→Lb | VH mutation frequency | ||||||
| % (number) | % (number) | % | |||||
| C57BL/6 | 4 | 24 | 8 (2) | 54 (13) | 5.1 ± 3.1 | 59 | 5.55 ± 2.8 |
| IL-21−/− | 1 | 12 | 42 (5) | 8 (1)# | 1.7 ± 2.5** | 14# | 2.86 ± 2.8# |
| IL-21R−/− | 3 | 28 | 61 (17) | 7 (2)* | 1.0 ± 1.9** | 18# | 2.64 ± 2.2** |
| Genotype | VH186.2− | VH186.2+a | Unmutated | Position 33 mutationb | VH mutation frequency | Excluding germline sequences | |
| Position 33 W→Lb | VH mutation frequency | ||||||
| % (number) | % (number) | % | |||||
| C57BL/6 | 4 | 24 | 8 (2) | 54 (13) | 5.1 ± 3.1 | 59 | 5.55 ± 2.8 |
| IL-21−/− | 1 | 12 | 42 (5) | 8 (1)# | 1.7 ± 2.5** | 14# | 2.86 ± 2.8# |
| IL-21R−/− | 3 | 28 | 61 (17) | 7 (2)* | 1.0 ± 1.9** | 18# | 2.64 ± 2.2** |
The VH mutation frequency is shown as mean mutation per VH gene. The VH mutation frequency ranges are the following: C57BL/6, 0–8; IL-21−/−, 0–9; IL-21R−/−, 0–7.
#, P < 0.05; *, P < 0.005; **, P < 0.001.
Sequences from single cell PCR were analyzed exactly as previously described (Blink et al., 2005) to define VH186.2 and mutations.
Percentage of sequences containing mutations that results in an amino acid replacement of tryptophan with leucine at position 33.