[Molecular mechanisms of the initiation of complete and mosaic mutations]

To study the molecular basis of the origin of complete and mosaic mutants, pBR322 plasmid with one- or two-stranded DNA damage was constructed by limited chemical modification of the plasmid DNA. Damage of one strand of DNA resulted in induction of mosaic mutants. Data were obtained indicating that complete mutations arise as a result of damage of two strands in the region of the mutagenized gene.