TABLE 3.
Rates of microsatellite instability in mismatch repair defective strains
| nt in repeat unit | genotype | average rate of tract alteration (X 10−6)a | relative rate |
|---|---|---|---|
| 1 | wild-type | 4.2 (3.2–6.2)* | 1.0 |
| msh2Δ | 20,000 (14,000–23,000) | 4,800 | |
| msh3Δ | 740 (560–1,200) | 180 | |
| msh2Δ1 | 760 (500–1,500) | 190 | |
| msh6Δ | 83 (46–120) | 20 | |
| msh3Δ msh6Δ | 13,000 (9,700–20,000) | 3,100 | |
| msh2Δ1 msh3Δ | 1,800 (1,200–2,400) | 440 | |
| msh2Δ1 msh6Δ | 16,000 (11,000–21,000) | 3,700 | |
| 2 | wild-type | 1.5 (0.7–2.0) | 1.0 |
| msh2Δ | 540 (420–890) | 360 | |
| msh3Δ | 79 (37–120) | 53 | |
| msh2Δ1 | 85 (52–140) | 57 | |
| msh6Δ | 3.1 (1.7–9.0) | 2.1 | |
| msh3Δ msh6Δ | 600 (290–870) | 400 | |
| msh2Δ1 msh3Δ | 120 (90–150) | 79 | |
| msh2Δ1 msh6Δ | 550 (380–980) | 370 | |
| 4 | wild-type | 2.1 (1.6–3.0) | 1.0 |
| msh2Δ | 120 (74–170) | 57 | |
| msh3Δ | 130 (72–160) | 62 | |
| msh2Δ1 | 110 (75–130) | 53 | |
| msh6Δ | 2.2 (1.1–3.4) | 1.0 | |
| 5 | wild-type | 5.9 (4.2–9.7) | 1.0 |
| msh2Δ | 77 (66–110) | 13 | |
| msh3Δ | 75 (61–110) | 13 | |
| msh2Δ1 | 77 (58–110) | 13 | |
| msh6Δ | 8.0 (4.4–12) | 1.4 | |
| 8 | wild-type | 3.5 (2.8–4.6) | 1.0 |
| msh2Δ | 30 (19–35) | 8.6 | |
| msh3Δ | 30 (25–49) | 8.6 | |
| msh2Δ1 | 29 (24–37) | 8.3 | |
| msh6Δ | 3.9 (1.7–8.0) | 1.1 |
a
Rates are in tract alterations per cell division.17
*
Numbers in parentheses indicate 95% confidence intervals. Microsatellite instability rates and 95% confidence intervals were calculated as described in the Materials and Methods from 14–21 individual cultures. The indicated strains were transformed with the reporter plasmids containing the indicated repeat unit (Table 1).