Divergence of transcription factor occupancy sites between human and mouse.

<p>A) For each TF (GATA1, TAL1, KLF1, and NFE2), a narrow occupancy site (summit +/- 50 bp) was mapped from mouse ProEs (mm10) to hg19 coordinates using the UCSC liftOver tool and intersected with corresponding peaks in human ProEs. To investigate “compensatory” new occupancy sites in hg19, narrow peaks that were mapped were expanded 5000 bps in each direction and the overlap was recomputed. The denominator (blue, orange, green, or purple plus white) represented the total number of mapped peaks from mouse ProEs to hg19, and the numerator (blue, orange, green, or purple) represented the total number of these mapped peaks that overlap with peaks in human ProEs, referred to as “conserved” occupancy in the main text. B) Similar to A), except that peaks in human ProEs (hg19) were mapped to peaks in mouse ProEs (mm10). Please note that the total number of peaks mapped from mouse to human is smaller than the number mapped from human to mouse. C) Similar to B), except that peaks in the K562 erythroid cell line were directly intersected with peaks in human ProEs. KLF1 data was not available for K562 cells so no overlap was computed. D) For each peak in human and mouse ProEs, MeME-Chip was used to recover canonical motifs for each TF (GATA1, TAL1, KLF1, and NFE2) in a small window (+/- 50 bps) around the summit of each peak. The probability density for each motif is shown across the region (for example, a density of 14 is a probability of 0.14 on a 0 to 1 scale). <i>Abbreviations used</i>: ProEs, pro-erythroblasts; N.C.E, no central enrichment.