Dose-response curves are presented for the frequencies of sister chromatid exchange (SCE) and structural chromosomal aberrations in cells from gills of Mytilus edulis exposed, in vivo, to differing concentrations of mitomycin C (MMC). Appropriate statistical methodology is derived for the resulting Poisson and binomially distributed counts, in the presence of between-animal variation. Both SCE and structural abnormalities increased in frequency with higher mutagen levels, but greater sensitivity is demonstrated for SCE. SCE frequency in controls, 4.1 per metaphase, is similar to baseline levels quoted for other aquatic organisms. This novel application of the SCE technique to a somatic tissue in Mytilus , an important species in pollution research, represents a significant advance towards the development of a cytogenetic method for detecting and monitoring genotoxic pollutants in the marine environment. |
