Figure 6.

Age or regenerative stress-induced p16 expression is attenuated in Smurf2-deficient mice. (A) Quantitative RT–PCR analysis of gene expression in bone marrow (BM) and sorted LSK (Lin⁻Sca1⁺c-kit⁺⁺) cells of young (2-month) and old (24-month) wild-type (+/+) and Smurf2^T/T (T/T) mice. Relative expression in young wild-type cells was set to be 1 after normalization with β-actin. Only P < 0.05 are indicated in pairwise comparison. (B) Quantitative RT–PCR analysis of gene expression in BM of donors and successive recipients in serial transplantation. Relative expression in wild-type donors is set to be 1 after normalization with β-actin. Error bars are calculated from standard deviations of three independent experiments. Student’s t-test is used for statistical analysis. *P < 0.05, **P < 0.01, ***P < 0.001, ns: not significant.