Fig. 5: Analysis of telomeres by DNA sequencing.

a Telomeres VI-R were amplified and sequenced from clonal populations of est2∆ and est2∆ nup1-LexA cells using a specific primer after about 65 population doublings from the initial spores (Day 5) and align with the reference sequence obtained at Day 1 (see Supplementary Fig.  4a for the senescence profiles). Each bar represents an individual telomere. Bars are sorted by the length of the centromere-proximal sequence that is identical to the reference sequence (black). The red bars show the length of the distal rearranged sequence that cannot be continuously aligned with the reference. b Examples of rearrangements. Upper panel, deletion: TelVI-R from the clone a1 aligns with the reference provided that a 8-bp-long gap is introduced after the 17th nucleotide. Note the repeated motif (in red and blue) at and after the gap. Lower panel, insertion: The 55 first nucleotides of the clone e1 align perfectly with the reference. The last 60 nucleotides (56–86 are shown) cannot be aligned with the reference except if starting at position 29 of the reference instead of 56. This suggests that part of the sequence has been duplicated. Note the presence of the motif (in blue) at the end of the conserved sequence that is repeated just upstream the point of misalignment (in red). c Model of non-conservative HR-dependent repair between sister chromatids. The sequence of the telomeres contains motifs that are repeated several times. Thus a 3′ terminal end with such a motif can anneal at different positions in the sister chromatid to initiate repair leading to internal deletion (left part) or duplication (right part).