Genotoxic effects of 8-hydroxylquinoline in loach (Misgurnus anguillicaudatus) assessed by the micronucleus test, comet assay and RAPD analysis.

This study was a preliminary step in evaluating the genotoxic effects of 8-hydroxylquinoline (8-HOQ) in loach (Misgurnus anguillicaudatus) using the micronucleus, comet and RAPD assays. In the micronucleus test and comet assay, the micronuclei rate (%) and three comet parameters (trailing rate, tail length and tail moment) in treated fish increased with increasing 8-HOQ concentration and treatment time. These results showed that exposure to 8-HOQ significantly induced genetic toxicity in loach blood cells. A subsequent RAPD assay also showed that 8-HOQ induced a genotoxic effect in loach. Among the 23 tested RAPD primers, 11 primers produced unique polymorphic band patterns and generated RAPD profile variations that displayed the band intensity, disappearance of bands and appearance of new bands of amplified DNA in the 8-HOQ-treated genomic DNA samples. In addition, the variation in RAPD profiles was time- and concentration-dependent. These results suggested that 8-HOQ is potentially harmful to fish and may be a toxic contaminant in the aquatic environment.