Relative expression levels of SIRT1 and zyxin mRNA in various mouse tissues and developmental stages. (A) Quantitative real-time PCR expression profiles of mouse cDNA from different tissues. The expression levels of SIRT1 and zyxin relative to those of GAPDH were assessed by ΔΔCt method. Results are the mean ± S.E from three independent reactions. (B) Real-time PCR expression profiles of mouse cDNA from whole brain at different developmental stages. The expression levels of SIRT1 and zyxin mRNA are represented as relative fold as compared with the value in brain(A) and P1(B). E13, 15, 17; Embryonic day 13, 15, 17. P1, P2w, P4w: Post natal day 1, 2 weeks, 4 weeks.