Gamma radiation induced cell cycle perturbations and DNA damage in Catla Catla as measured by flow cytometry

• Cell cycle perturbations and DNA damage were studied in Catla catla using FCM.
• Gamma radiation effects using FCM under laboratory conditions is first of its kind.
• DNA repair and apoptotic cascade at protracted and acute doses.
• FCM an alternate tool to study the genotoxic events of physical contaminants.

Gamma radiation induced cell cycle perturbations and DNA damage in Catla catla were analyzed in erythrocytes at different time points using flow cytometry (FCM). Protracted exposure to radiation induced damage between days 12 and 45. Disturbances in cell cycle machinery, i.e., proportional increase and decrease in Gap0 or quiescent/Gap1 (G0/G1), Synthesis (S) and Gap2/Mitotic (G2/M) phases were observed at both acute and protracted treatments. Both acute and protracted exposures induced apoptosis with a notable significance between days 3 and 6 at protracted and on day 45 at acute doses. Fish exposed protractedly avail some DNA repair mechanisms than acutely exposed. This is the first study to analyze radiation induced DNA damage under laboratory conditions and suggests that flow cytometry can also be an alternate tool to screen genotoxicity induced by ionizing radiation in fish.