Figure 4: POT1R117C carriers present longer telomeres.
(a) Telomere length (TL) analysis by qPCR (t/s ratio) for family 1 members (n=29). (b) TL analysis by qFISH of primary immortalized LCLs corresponding to non-carriers (II-1 and III-16) and p.R117C carriers (II-4 and III-15). (c) Percentage of telomeres shorter than 3 kb of primary immortalized LCLs corresponding to non-carriers (II-1 and III-16) and p.R117C carriers (II-4 and III-15). (d) TRAP Tel/IC ratio values for telomerase activity calculated from primary lymphocytes of different members of family 1 (n=7). In b–d two independent experiments with samples in triplicate were performed. (e) Left panel: number of telomere sister chromatid exchange (T-SCE) events/metaphase in primary lymphocytes by CO-FISH (n=2 individuals per genotype in triplicate). Right panels: representative CO-FISH images showing the leading (green) and lagging (red) telomere strands. T-SCEs are indicated with arrows. DAPI (blue) was used for DNA labelling. Below a magnified merge image is shown. Scale bar, 1 μm. (f) Upper panel: per cent of cells positive for ultra-bright spots (ubs) at telomeres by FISH in three different paraffin-embedded cardiac tumour (T) and normal (N) tissue samples carrying the mutation from members of family 2 (F2) and 3 (F3). Lower panel: examples of large red spots corresponding to positive signals (white arrows). DAPI (blue) was used for DNA labelling. Scale bar, 10 μm. (g) TL adjusted for age of wt and p.R117C carriers of all members of families 1, 2 and 3 and the 3 CAS tumours. DNA from CAS samples was extracted from paraffin-embedded tissues. Values are expressed as mean+s.e. and the two-tailed student’s unpaired t-test was used for the statistical analysis, NS, not significant.
