DNA Double-Strand Breaks (IMAGE) Osaka University Caption These are DNA double-strand breaks, introduced by ionizing radiation or other mechanisms, are repaired rapidly and precisely in normal cells (right pathway). In contrast, compromised Tel1 activation with inefficient end joining activity in the mutant promotes accumulation of Ku protein at single-stranded DNA ends at the damaged site, and then, results in imprecise repair of genomic DNA (left pathway). Credit Osaka University Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.