Increase in the mitotic recombination frequency in Drosophila melanogaster by magnetic field exposure and its suppression by vitamin E supplement.
In order to estimate possible mutagenic and/or carcinogenic activity of electromagnetic fields, wing spot tests were performed in Drosophila melanogaster. A DNA repair defective mutation mei-41D5 was introduced into the conventional mwh/flr test system to enhance mutant spot frequency. Third instar larvae were exposed to a 5-Tesla static magnetic field for 24 h, and after molting, wings were examined under a microscope to detect hair spots with mutant morphology. The exposure caused a statistically significant enhancement of somatic recombination compared with the unexposed control. This enhancement was suppressed to the control level by supplement of vitamin E, a non-specific antioxidant. It is inferred that the magnetic field enhanced the genotoxic effect of spontaneously produced free radicals, possibly by affecting the lifetime of the radicals. Enhancement of non-disjunction, terminal deletions and gene mutations were not detected.
Koana
T
T
Environmental Biotechnology Laboratory, Railway Technical Research Institute, Tokyo, Japan. koana@rtri.or.jp
Okada
M O
MO
Ikehata
M
M
Nakagawa
M
M
D000818:Animals; D004260:DNA Repair / Q000235:genetics; D004331:Drosophila melanogaster / Q000235:genetics*; D004574:Electromagnetic Fields / Q000009:adverse effects*; D005609:Free Radicals / Q000378:metabolism; D007814:Larva / Q000528:radiation effects; D008938:Mitosis / Q000528:radiation effects*; D011995:Recombination, Genetic / Q000528:radiation effects*; D014466:Ultraviolet Rays / Q000009:adverse effects; D014810:Vitamin E / Q000494:pharmacology; D014921:Wings, Animal / Q000002:abnormalities
D005609:Free Radicals; D014810:Vitamin E