Evaluation of gamma radiation–induced genotoxicity in the workers of Italian honey bees, Apis mellifera ligustica, using single cell gel electrophoresis (comet) assay

Abstract

The environment exposed to radionuclide faces detrimental effects of ionizing radiations and these radiations can damage DNA by inducing genotoxicity in living organisms. The gamma radiation induced genotoxicity was evaluated by employing Single cell gel electrophoresis (comet) assay in the foragers of Apis mellifera ligustica by exposing to different doses (1 to 60 Gy) of gamma radiation. DNA damage was measured as the percentage of comet tail DNA. The results showed a dose dependent increase and post irradiation time (1-24 h) dependent decrease in % tail DNA level in bee foragers. A significant increase in DNA damage was observed in all the samples and the extent of damage was proportional to the dose of gamma radiation received by the bees except in those treated with the lower doses (1, 5 and 10 Gy) of gamma radiation. The highest amount of DNA damage was recorded at 1 h post-irradiation which decreased gradually with time, that is, at 3 h and 6 h post-irradiation. However, there were no significant differences in the % tail DNA of bees of 12 h and 24 h post irradiation. The present study shows gamma radiation induced DNA damage in foragers of A. m. ligustica and also the comet assay is a suitable technique for detection of gamma radiation induced DNA damage.