Species-specific and conserved transcription factor occupancy associates with histone modifications.

<p>A) Emission states of chromatin structure from ChromHMM. Darker blues correspond to higher percentage of representation in a specific state. In addition to chromatin modifications, states are compared to known genomic regions where darker blues correspond to increased fold enrichment versus expected. Each state was highly correlated (pearson correlation values shown) with at least one state in models learned separately in human ProEs, mouse ProEs, and K562 cells. B)–F) Chromatin state enriched in B) TF occupancy sites conserved between human and mouse, C) compensatory TF occupancy sites that are human-specific and proximal (+/- 5kb) to a lost TF occupancy site during evolution, D) human-specific occupancy sites that are gained during evolution, E) mouse-specific occupancy sites that are lost during evolution, and F) top 10% of human occupancy sites based upon mapped reads. Probability of enrichment is scaled across all peak regions. Overall, promoter and enhancer regulatory regions are decreasingly enriched for conserved, compensatory and human-specific, and finally mouse-specific occupancy sites. G) Human-specific genes are defined as the top 10% of differentially expressed genes in human ProEs and mouse-specific genes are defined as the top 10% of differentially expressed genes in mouse ProEs. For each category of TF occupancy, log2 odds ratios for the frequency of TF occupancy in human- or mouse-specific genes are compared to this frequency in the remaining 90% of genes. <i>Abbreviations used</i>: ProEs, pro-erythroblasts.