TY - JOUR
T1 - The genotoxicity of uva irradiation in drosophila melanogaster and the synergistic action of 8-methoxypsoralen and uva
AU - Negishi, Tomoe
AU - Tanabe, Fujimi
AU - Hayatsu, Hikoya
N1 - Funding Information:
We thank Dr K.Fujikawa of Takeda Chemical Industries and Dr H.Ryo of Osaka University, for generous gifts of Drosophila strains and for valuable discussion. This work was supported by a Grant-in-Aid for Cancer Research (no. 03151042) from the Ministry of Education, Science and Culture
PY - 1992/8
Y1 - 1992/8
N2 - 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 (̃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 the 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 hethoxypsoralen (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 μM 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 chrommosomal recombinations took place in the somatic cells.
AB - 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 (̃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 the 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 hethoxypsoralen (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 μM 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 chrommosomal recombinations took place in the somatic cells.
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U2 - 10.1093/carcin/13.8.1433
DO - 10.1093/carcin/13.8.1433
M3 - Article
C2 - 1499094
AN - SCOPUS:0026793495
VL - 13
SP - 1433
EP - 1436
JO - Carcinogenesis
JF - Carcinogenesis
SN - 0143-3334
IS - 8
ER -