Chromosomal aberrations induced by the restriction endonucleases EcoR I, Pst I, Sal I and Bam HI in CHO cells

Abstract 4 widely used cohesived end-producing restriction enndonucleases (REs), EcoR I, Pst I, Sal I and Bam HI were tested in CHO cells for their aberration-inducing effects. It was demonstrated that all these REs significantly increased the frequencies of aberrant cells, the aberration frequencies per cell and the aberration frequencies per chromosome. The effects of REs on chromosomal aberrations are similar to ionizing radiation, but more minutes and interchange fiqures are observed. Polyploid cells are more susceptible to RE treatment, an interesting finding which may be explained by the mechanisms leading to the formation of polyploid cells.