Evaluation of Gamma Radiation Induced DNA Damage in Bombyx mori, using Single Cell Gel Electrophoresis (Comet Assay)

Ashok R; Shetty N.J; Hariprasad T.P.N

Abstract

Bombyx mori (B. mori) is the model insect used in the present study, which is commercially important compared to other Lepidopterans. Eggs of late embryonic stage (7 day old) of B. mori were exposed to different doses of gamma radiation to study the extent of DNA damage using comet assay which is a rapid technique to study the genotoxic effects. Test samples were exposed to varied doses of radiation (100, 250, and 400 Gy) to evaluate the genotoxicity at 60, 90 and 120 min post irradiation. The results showed that Olive tail moment (OTM) in all the samples had significant linear increase (P≤0.05) in DNA damage. The maximum DNA damage was observed 60 min post irradiation to all the doses while the maximum damage was at 400 Gy (60.1±3.52) compared to the control. The damage was found to be gradually decreasing at higher time points of 90 and 120 min for all the doses, indicating the activity of DNA repair mechanisms. We also observed that, the intensity of the DNA damage aggravated with increase in dose and time post irradiation. The outcome of this study can be used as an important biomarker for environmental risk assessment.

Abstract

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