Table 2.
.Mutational frequency in IgM and IgG from young and aged humans
| Mutational frequency, % (no. of mutations/No. of total analysed bases) | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| CDR | FR | ||||||||
| No. of analysed sequences | VH region | CDRs | CDR1 | CDR2 | FRs | FR1 | FR2 | FR3 | |
| IgM memory | |||||||||
| Young | 59 | 3·4* | 5·5 | 8·1 | 4·7 | 2·7 | 2·8* | 1·3 | 3·3 |
| (583/17 346) | (214/3894) | (72/885) | (142/3009) | (369/13 452) | (148/5310) | (33/2478) | (188/5664) | ||
| Aged | 39 | 3·9* | 6·4 | 10·4 | 5·3 | 3·1 | 3·5* | 1·4 | 3·5 |
| (445/11 466) | (166/2574) | (61/585) | (105/1989) | (279/8892) | (124/3510) | (23/1638) | (132/3744) | ||
| IgG | |||||||||
| Young | 86 | 5·8** | 8·9** | 11·9* | 8·1** | 4·9** | 4·7** | 3·0 | 5·8** |
| (1,463/25 284) | (508/5676) | (153/1290) | (355/4386) | (955/19 608) | (366/7740) | (110/3612) | (479/8256) | ||
| Aged | 78 | 7·6** | 11·3** | 14·8* | 10·3** | 6·6** | 6·4** | 3·5 | 8·1** |
| (1753/22 932) | (584/5148) | (173/1170) | (411/3978) | (1169/17 784) | (452/7020) | (114/3276) | (603/7488) | ||
*
P < 0·05;
**
P < 0·01.