Figure 6.

Bisulfite Modification and Pyrosequencing Verification of CpG-Methylation Differences in Two Genes Nominated from Microarray Analysis

(A) Microarray signal intensity for probes located in CpG islands in the promoter region of WDR18 and RPL39. Scale bars denote 95% confidence intervals. For WDR18, male SZ samples had significantly higher intensities than did unaffected control samples (raw p = 4.5E-05, FDR corrected = 0.05), indicating hypomethylation in affected individuals. For RPL39, female BD samples had significantly lower intensities than unaffected control samples (raw p = 4.0E-05, FDR corrected = 0.02), indicating hypermethylation in affected individuals.

(B) Bisulfite mapping across amplicons spanning regions interrogated by CpG-island microarrays confirms DNA-methylation changes predicted by microarrays: shown are WDR18 hypomethylation in male SZ samples (p < 0.001) and RPL39 hypermethylation in female BD samples (p = 0.009).

(C) Predicted transcription-factor binding sites in the regions of WDR18 and RPL39 analyzed by pyrosequencing. Boxes indicate CpG sites with the largest DNA-methylation differences in affected individuals.

(D) Example pyrograms demonstrating relative WDR18 hypomethylation in a SZ male sample and RPL39 hypermethylation in a BD female sample.