Use of comet assay in the study of DNA break in blood and gill cells of rohu (Labeo rohita) after an exposure to furadan, a carbamate pesticide

Labeo rohita (rohu) fingerlings were exposed to 0.002, 0.004 and 0.02ppm of Furadan, a carbamate pesticide for 96h. Samplings were done at 24, 48, 72 and 96h. The study was intended to assess tissue specific genotoxic effects produced by furadan on two different tissue systems in fish. Results showed low baseline DNA break in blood cells followed by gill in control group whereas more DNA breaks in gill followed by blood cells in treated individuals. Concentration-dependent DNA breaks (AU) showed a linear and positive relationship (r(2) = > 0.7) in both the tissues. Time response curves showed a significant rise in AU up to 48h followed by a fall at 96h in blood. In gill inclination in 0.002 and 0.02ppm treated fishes continued up to 72h followed with a plunge at 96h. The results allowed us to advocate that rohu is a potential biomonitoring animal, comet assay can be used in DNA break studies and response to pollutants in multicellular animals is often tissue specific.