Distribution of mitomycin C induced breaks on human chromosomes

Abstract

Mitomycin C induced chromosome aberrations were analysed in cultured human lymphocytes by the quinacrine mustard chromosome banding technique. There was an overrepresentation of interchange aberrations involving the C-bands of homologous chromosomes, and especially the secondary constrictions of chromosomes 1, 9 and 16. Interchanges involving other bands rarely occurred between homologous chromosomes. These findings indicate that the C-bands are aggregated in the cell and/or that such an aggregation is induced by mitomycin C. The chromatid and chromosome breaks appeared to be located preferentially in the R-bands.