Extended Data Figure 2.

Related to Figure 2

a, Representative metaphase spreads of TRF2ts MEFs transduced as indicated, harvested after 24 h at 39°C for telomere fluorescence in situ hybridization (FISH). b, Representative telomeric single-strand G-overhang (ss TTAGGG) and total telomere (total TTAGGG) analysis in TRF2ts MEFs at 32°C and after 48 h at 37°C or 39°C. c-d, Mad2l2 knockdown does not affect cell cycle parameters in TRF2ts MEFs. Cell cycle phase analysis was based on PI staining of asynchronously growing cells (c), as well as on 1 h incubation with BrdU, followed by detection of BrdU incorporation and PI staining for DNA content (d) (n=3, ± s.d.). e, MAD2L2 is required for sister-telomere fusion upon activation of DNA repair in mitosis. Sister-telomere fusions were quantified in IMR90 cells expressing exogenous WT 53BP1 and RNF8, or 53BP1-T1608A/S1618A (TASA) and RNF8-T198A (TA) mutant alleles, and depleted for endogenous RNF8 and 53BP1, as well as depleted for MAD2L2, RIF1 or PTIP (n=4). f, Examples of DNA content profiles of PI stained TRF2ts cells transduced with the indicated shRNAs and grown at 32°C or for 48 h at 39°C. Analysis of the fraction of cells with 8N (tetraploid) or > 4N (aneuploid) DNA content was done on corresponding dotplots of which the results are shown in Fig. 2c.