The effect of gamma radiation on the Common carp (Cyprinus carpio): In vivo genotoxicity assessment with the micronucleus and comet assays

Abstract

Radioactive wastes may be leached into freshwater, either accidentally or in industrial effluents. Wehave studied gamma radiation-induced DNA damage in the freshwater fish Cyprinus carpio. Fish wereirradiated with 2-10 Gy gamma radiation and genotoxic effects in blood cells were studied with themicronucleus (MN) and comet assays. Micronuclei and a dose-dependent increase in comet-tail DNAwere seen in dose- and time-dependent studies. The highest % tail DNA was observed at 24 h, declininguntil 72 h, which may indicate the repair of radiation-induced DNA single-strand breaks after gammaradiation. However, double-stranded DNA damage may not have been repaired, as indicated by increasedmicronuclei at later periods. A positive correlation was observed between the comet and micronucleusassay results. This study confirms the mutagenic/genotoxic potential of gamma radiation in the Commoncarp, as well as the possible combined use of the micronucleus and comet assays for in vivo laboratorystudies with fresh-water fish for screening the genotoxic potential of radioactive pollution.