TABLE 1.
Classification of mutants
| Type of mutation | No. (%) of virus samples that induced mutation
|
|
|---|---|---|
| KOS (n = 66)a | Y7 (n = 66) | |
| Base substitution | 22 (33.3) | 52 (78.8) (P < 0.005) |
| Single change | 22 | 41 |
| Double changes | 0 | 10 |
| Triple changes | 0 | 1 |
| Frameshift | 45 (66.6) | 14 (21.2) (P < 0.005) |
| Insertion of G or C | 30b | 9 |
| Deletion of G or C | 14 | 5 |
| Deletion of A or T | 1 | 0 |
a
One mutant derived from KOS strain contains a base substitution and frameshift mutation in fragments II and III, respectively.\
b
One mutant contains an insertion of two G's at sequences of seven G's.