Discretized histone modification patterns are not uniformly distributed. The most prominent pattern is labeled 1, where ChIP intensities are elevated downstream of both genes, but diminished throughout the bidirectional promoter. Also prominent are patterns 2 and 3, where the ChIP intensities are just elevated in one downstream gene (the genomic forward direction or reverse direction, respectively). The pattern labeled 4 represents the case where ChIP intensities are elevated in the bidirectional promoter as well as both downstream genes, and 5 represents no elevation throughout the region. The number 6 represents three remaining patterns: elevated ChIP intensities in the bidirectional promoter but diminished in both downstream promoters, elevated ChIP intensities in the bidirectional promoter and downstream of the forward gene, but diminished in the reverse gene, and elevated ChIP intensities in the bidirectional promoter and downstream of the reverse gene, but diminished in the forward gene.
