Distribution of S1-nuclease Sensitive Sites and Double-strand Breaks in γ-irradiated λ-DNA

SummaryDouble-strand breaks and regions with unpaired bases (S1-nuclease sensitive sites) are formed in the DNA of γ-irradiated λ-phages. The frequency of both events was determined in the various fragments produced after digestion with a restriction enzyme (Eco RI). The results show that both types of radiation damage are randomly distributed in the DNA molecule. There is no hint that the S1 sites are formed in preferred regions of the λ-genome.