Fig. 5: Nicotine exposure-induced DNA Methylation changes in sperm are partially reversible.

A Detection of 5-methylcytosine (5-mC) proportion using HPLC (n = 5 mice per group). B Global sperm DNA methylation levels across the three groups. C DNA methylation levels in various regions of the whole sperm genome. Methylation levels of 393 hypermethylated (D) and 184 hypomethylated (E) differentially methylated regions (DMRs) across the three groups (NIC mice relative to CON mice). F Heatmap for 259 differentially methylated transcription start sites (TSSs) in the three groups (NIC mice compared to CON mice). G GO analysis of hypomethylated TSSs in NIC mice compared to CON mice. H The visualization of methylation levels in promoter regions of Irf7 and Sycp3. Pyrosequencing analysis (n = 4 mice per group) on the promoter regions of Irf7 (I) and Sycp3 (J). Pyrosequencing analysis (n = 5 per group) on the promoter regions of IRF7 (K) and SYCP3 (L) in human sperm samples. Data are represented as mean ± SEM. All statistical analyses were performed using ANOVA followed by Bonferroni’s multiple comparisons test, **p < 0.01; *p < 0.05; ns not significant.