Figure 2.

Super-p53 mouse embryo fibroblasts respond to telomere dysfunction by activating the p53/p21 pathway. (A) Representative example of the levels of p53 and p21 in cell extracts from early-passage primary mouse embryo fibroblasts (MEFs) of the indicated genotypes. The band labelled as n.s. is nonspecific for p53. Bands from Ponceau S-stained western blots were used as loading control. The blots shown are representative of three experiments. (B) Quantification of p21 protein levels. Data are relative to p21 levels in wild-type MEFs. For each genotype, several independent MEF cultures (derived from different embryos) were assayed, indicated at the bottom of the figure (n). Data correspond to the average±s.d.