Figure 5. .

Age-related DNA methylation changes in the sperm. Individuals were ordered by increasing age (top left panel), and gene-specific DNA methylation dynamics were investigated using the individual ages (sperm DNA–HpaII age range 24–56 years) as a covariate. Pearson correlation was calculated for each locus, and the one-tailed P value of the coefficient was obtained. In the sperm DNA–HpaII data set, 105 loci were identified as significantly (P<.05) correlated (r>0.5) or inversely correlated (r<-0.5) with age. Since the unmethylated fraction of DNA was interrogated, positive correlation indicates decreasing DNA methylation with age, whereas inverse correlation reflects increasing methylation with age. The genes CTNNA2, EED, CALM1, CDH13, and STMN2 are shown as examples. Other genes for the sperm DNA–HpaII, sperm DNA–HHA, and brain DNA–HpaII data sets are available in tables 3 and 4.