Fig. 1: DNA resection contributes to deletion formation at telomere fusion.

a Diagram of 21q/16p TALEN induced telomere fusion PCR assay, with position of primers, the distance of primers to the cleavage site and the expected size of fusion product indicated. b 21q1 + 16p1 telomere fusion analysis (a representative image from two independent experiments) using the indicated amount of DNA isolated from RPE1-hTERT (RPE1) cells 48 h after TALEN nucleofection. Telomere fusion products were detected with a 16p telomere adjacent probe. c Fusion between 21q and 16p family telomeres characterized by Sanger sequencing of re-amplified and purified PCR products, with the number of nucleotides deleted indicated by Δbp. d 21q1 + 16p1 telomere fusion assay using DNA (50 ng) isolated from RPE1 cells at the indicated time after nucleofection. e 21q1 telomere fusion assay (a representative image from four independent experiments) using DNA (50 ng) isolated from RPE1 cells 48 h after nucleofection. Telomere fusion products were detected with a 21q telomere adjacent probe. f, g Examples of fusion between 21q family telomeres characterized by Sanger sequencing of re-amplified and purified PCR products, with the number of nucleotides deleted (Δbp), microhomology (MH) and insertions (in) indicated. h, i 21q1 or 21q1 + 16p1 telomere fusion assay using DNA (50 ng in h, 1.6 ng in i) isolated from HCT116 WT or LIG3/LIG4 KO cells 48 h after nucleofection, with quantification of fusion bands from three independent experiments shown in Supplementary Fig. 1d–e. j, k 21q1 or 21q1 + 16p1 telomere fusion assay using DNA (50 ng in j, 1.6 ng in k) isolated from RPE1 cells treated with DMSO or 50 µM mirin 48 h after nucleofection, with quantification of fusion bands from two/three independent experiments shown in Supplementary Fig. 1f–g.