Fig. 4.

Essential role of Gadd45b in activity-induced specific DNA demethylation and gene expression in the adult dentate gyrus. (A and B) Bisulfite sequencing analysis of adult dentate gyrus tissue before or at 4 hours after ECT. (A) A schematic diagram of the genomic region subjected to analysis and a summary of methylation frequency at individual CpG sites. (B) A summary of mean DNA methylation levels of individual alleles. Values represent mean ± SEM (n = 10 to 15 reads; **P < 0.01, *P < 0.05, ^#P > 0.1, ANOVA; exact P values are given in table S2). (C) Methylation-specific PCR analysis from the dentate gyrus of WT mice after one or two ECTs (“24+4”: 4 hours after two ECTs at 24 hours apart) or 7 days after lentivirus-mediated expression of Gadd45b-GFP or GFP alone without ECT. Primers are specific for methylated (M) and unmethylated alleles (UM) of the Fgf-1B promoter, or for bisulfite sequencing without CpGs (Input). (D) Summary of the mRNA and protein expression in the dentate gyrus of adult Gadd45b WT and KO mice at 4 hours after ECT and sham controls. Values represent mean ± SEM (n = 4 animals; *P < 0.01, ANOVA).