The genotoxicity of UVA irradiation in Drosophila melanogaster and the synergistic action of 8-methoxypsoralen and UVA
| Autor: | Fujimi Tanabe, Tomoe Negishi, Hikoya Hayatsu |
|---|---|
| Rok vydání: | 1992 |
| Předmět: |
Cancer Research
DNA damage DNA repair Ultraviolet Rays Mutant medicine.disease_cause Sex Factors In vivo Drosophilidae medicine Animals PUVA Therapy Genetics Spots biology Dose-Response Relationship Drug Methoxsalen Dose-Response Relationship Radiation General Medicine DNA biology.organism_classification Molecular biology Drosophila melanogaster Mutagenesis sense organs Genotoxicity medicine.drug DNA Damage |
| Zdroj: | Carcinogenesis. 13(8) |
| ISSN: | 0143-3334 |
| Popis: | To study the genotoxicity of near-ultraviolet light (UVA) on a whole body, Drosophila melanogaster larvae were irradiated with UVA and the emerging flies were examined for the mutant wing spot formation. The genotoxicity of UVA was also assayed with the in vivo DNA-repair test using males with repair-deficiency at the mei-9 and mei-41 locus and the matching repair-proficient females. Third-instar larvae were placed in a plastic Petri dish, which was covered with soft glass, and irradiated with black light at 4-5 W/m2. This irradiation resulted in an increase in mutant wing-hair spots. After a 15 h irradiation (approximately 240 kJ/m2), the mutant clone frequencies found in the adult flies (spots/wing) were: 1.68 for the small single spots, 0.38 for the large single spots and 0.11 for the twin spots, while at zero time they were 0.68, 0.06 and 0.02 respectively. On the other hand, the UVA irradiation was negative in the in vivo DNA-repair test, indicating that the UVA-induced DNA lesion may not be subject to repair by the mei-9 and mei-41 functions. The presence of 8-methoxypsoralen (8-MOP) during the irradiation remarkably enhanced somatic mutations, and showed a strong DNA-damaging effect in the repair test. For example, a 15 h UVA irradiation with 26.7 microM 8-MOP resulted in a 14-fold increase in the number of twin spots per wing as compared with the frequency obtained on treatment with UVA alone. Treatment of the larvae with 8-MOP alone gave no mutant clones or DNA damage. A high frequency in twin spot formation was also observed in this UVA + 8-MOP treatment, indicating that extensive chromosomal recombinations took place in the somatic cells. |
| Databáze: | OpenAIRE |
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