Table III. Chromosomal aberrations induced by irradiation during G2 and late S–G2 phase.
Genotype | 1.5 h |
3 h |
||||||
---|---|---|---|---|---|---|---|---|
Chromatid | Isochromatid | Exchanges | Total | Chromatid | Isochromatid | Exchanges | Total | |
wild type | 28 | 6 | 0 | 34 ± 6 | 11 | 4 | 0 | 15 ± 4 |
ATM–/– | 40 | 9 | 1 | 50 ± 6 | 19 | 11 | 0 | 30 ± 5 |
KU70–/– | 58 | 7 | 4 | 69 ± 8 | 10 | 7 | 1 | 18 ± 4 |
RAD54–/– | 37 | 10 | 1 | 48 ± 7 | 19 | 5 | 1 | 25 ± 5 |
ATM–/–/KU70–/– #1 | 131 | 13 | 0 | 144 ± 12 | 113 | 17 | 1 | 131 ± 11 |
ATM–/–/KU70–/– #3 | nd | nd | nd | nd | 77 | 71 | 0 | 148 ± 9 |
ATM–/–/RAD54–/– Rad54+ | 28 | 9 | 0 | 37 ± 6 | 32 | 4 | 0 | 36 ± 8 |
ATM–/–/RAD54–/– Rad54– | 43 | 8 | 0 | 51 ± 7 | 26 | 8 | 0 | 34 ± 8 |
Cells were subjected to 0.3 Gy γ–irradiation, then incubated with colcemid for 1.5 or 3 h, as indicated, and harvested. At least 100 metaphases at 1.5 h and at least 50 at 3 h were analysed. The data from ATM–/–RAD54–/–Rad54– cells were obtained after 5 days of Rad54 repression. Data were calculated and are presented as described for Table I. nd, not determined.