Low LET radiation induced persistent DDR foci are preferentially associated with telomeric DNA.

<p>(A) Representative micrographs of co-localizations between 53BP1 foci and telomeric-PNA probes (Telo) in 92–1 cells, at the indicated time points after 5 Gy of X-ray exposure. Scale bar: 10 μm (1μm in TAF panels. TAF: Telomere-associated foci). The average number of 53BP1 foci per cell and the percentage of 53BP1 foci co-localized with telomeres in 92–1 cells exposed to 5 Gy of X-rays (B) or carbon ions (C). Data are mean ± s.e.m. (n = 3). For the quantification analysis, 120 cells were analyzed for 53BP1 foci experiments and 100 cells for co-localization experiments.