Table 1.
Quantification of Eclosion and Chromosome Breakage after Irradiation
| Eclosion after Irradiation | ||||
|---|---|---|---|---|
| Percent Eclosion (n/SD) | ||||
| Genotype | 0 R | 2000 R | 4000 R | |
| Wild-type | 98.1 (1659/0.9) | 97.9 (1305/2.1) | 87.0 (1215/10.5) | |
| grapes | 97.2 (415/1.2) | 97.3 (345/1.1) | 75.4 (336/7.9) | |
| mei-41 | 95.7 (695/1.8) | 0.9 (427/0.9) | 0.0 (329/0.0) | |
| okra | 97.8 (874/1.6) | 14.1 (747/10.9) | 0.9 (606/1.8) | |
| p53 | 83.8 (1672/3.3) | 71.0 (1632/10.3) | 46.1 (1479/16.6) | |
| Chromosome Breakage and Mitotic Index after Irradiation | ||||
| Percent Broken Metaphase Shromosomes (n/SD) | Mitotic Index (n/SD) | |||
| Genotype | 0 R | 220 R | 0 R | 220 R |
| Wild-type | 4.7 (366/4.6) | 6.1 (583/3.0) | 1.82 (2425/0.2) | 1.42 (3379/0.1) |
| grapes | 5.3 (581/5.9) | 8.3 (515/6.0) | 1.49 (3048/0.4) | 1.31 (3558/0.2) |
| mei-41 | 11.5 (477/6.3) | 45.9 (341/8.3) | ||
| okra | 5.3 (622/3.7) | 36.9 (769/15.3) | ||
(Top) Eclosion after irradiation. Larvae were irradiated during third larval instar with 0, 2000, or 4000 R of X-rays. Eclosed adults were counted for up to 10 days after irradiation and expressed as percent of total pupae. All larvae that were irradiated formed pupae under these conditions. Data are averaged from three to five experiments.
(Bottom) Chromosome breakage and mitotic index following irradiation. Larvae were irradiated during third larval instar with 0 or 220 R of X-rays. Such low doses are typically used for measurement of chromosome breakage, presumably for increased sensitivity [10]. Larval brains were extirpated at 3 hr after irradiation, fixed, squashed, and stained with a DNA dye. For breakage assay, the percent of metaphase cells showing at least one chromosome breakage is quantified. For mitotic index, the number of mitotic nuclei was calculated and expressed as a percent of total nuclei; at least 3 brains were quantified for each genotype and dose.
n = number of pupae counted (in the top section of the table), metaphase cells (for chromosome breakage), or nuclei (for mitotic index). SD, standard deviation; wt, wild-type. Genotypes of mutants are as indicated.