Spontaneous and induced sister-chromatid exchanges in cultured mosquito cells

Four mosquito cell lines derived from species of the genus Aedes were examined for spontaneous and induced sister-chromatid exchanges by the BrdU-labelling method. The five agents tested for SCE induction were: ethyl methanesulphonate (EMS), methyl methanesulphonate (MMS), ethyl nitrosourea (ENU), methyl nitrosourea (MNU), and 5-bromo-2-deoxyuridine (5-BrdU). It was found that there is significant interspecific and even intraspecific variation in the spontaneous frequency of SCEs. All five agents were effective inducers of SCEs and the induction was dose-dependent within the range of chemical concentrations used. This study shows that the mosquito cell lines may provide a simple and reliable in vitro assay system for testing the genotoxic effects of various agents, particularly on insects.