Modifications of the histone H3 amino-terminal tail. Modifications that correlate with transcriptional states are indicated here as either 'on' or 'off'. The enzymes (either in yeast, Drosophila or human) known to modify the given sites are indicated in ovals. Green indicates activating enzymes or modifications and red repressive modifications or enzymes. S10 phosphorylation can be present in both repressed and active domains. See text for further details. Ac, acetylation; Me, methylation; P, phosphorylation.