Figure 3.

Masking potential of the methylome. (1) The ‘methylome' (gray disk) is embedded in the genome but is separated from the genomic promoter network (spheres). (2) Activation of the promoter net begins at a node in response to stimulation (thunderbolt) and initiates demethylation of the methylome at the location of the active promoter. (3) Demethylation is equilibrated with the intensity of promoter activity across the network. (4) Promoter network returns to baseline quiescence after end of stimulation, but is now ‘primed' for interaction with ambient DNA-binding factors (green arrows). (5) The methylome (displaced) bears the demethylated imprints or ‘mask' of the previously active promoters.