TABLE 3.
Ionizing radiation-induced chromosomal aberrations per 100 mitotic cellsa
| Strain and colcemid treatment time (h) | Chromatid
|
Chromosome
|
Exchange(s) | Total ± SE | ||
|---|---|---|---|---|---|---|
| Breaks | Gaps | Breaks | Gaps | |||
| Wild type | ||||||
| 0–3 | 17 | 1.3 | 2.7 | 4.7 | 0.7 | 26 ± 4 |
| 3–6 | 4.7 | 0.7 | 1.3 | 4.7 | 0 | 11 ± 3 |
| 6–9 | 1.3 | 0.7 | 7.3 | 2.7 | 1.3 | 13 ± 3 |
| 9–12 | 0 | 1.3 | 3.3 | 4 | 2.7 | 11 ± 3 |
| RAD51B−/− | ||||||
| 0–3 | 70 | 9 | 16 | 8 | 5 | 108 ± 10 |
| 3–6 | 4 | 1 | 11.3 | 9.3 | 1.3 | 27 ± 5 |
| 6–9 | 1.3 | 0 | 6.7 | 10 | 1.3 | 19 ± 4 |
| 9–12 | 2 | 0 | 13.3 | 8.7 | 0 | 24 ± 5 |
a
One hundred fifty mitotic cells were analyzed for each genotype after treatment with 2 Gy of ionizing radiation. The data shown are the numbers of chromosomal aberrations induced by radiation treatment minus the number of spontaneous chromosomal aberrations. Cells were treated with colcemid for the indicated periods after irradiation. The number of total aberrations per cell ± the standard error was calculated as described in Table 1, footnote a. The data for wild-type cells are from our previous study (58).