Fig. 3

Increase of time to senescence and accelerated telomere shortening of FRDA fibroblasts. a Cumulative population doubling (CPD) times of human FRDA and normal fibroblast cell lines. Every cell passage is indicated by a point and the CPD was calculated based on the sum of the cell proliferations over the cumulative time taken from the earliest passages until cells underwent senescence. b The average rates of telomere shortening in the human FRDA and normal fibroblasts in bp/population doubling. P7, P15 and P26 = 7th, 15th and 26th passages following acquisition from the Coriell Cell Repository (Table 1), respectively. Data are shown as mean ± SEM. All the experiments were repeated at least twice independently, n = 3. c The telomere length shortening (bp/PD) of FRDA fibroblasts compared to controls throughout growth