Dynamic CTCF occupancy during hematopoiesis. (A) Schematic of the primary human blood cells analyzed. HSPCs, T cells, B cells, and monocytes were purified by their corresponding purification beads. Erythroblasts were differentiated in vitro from HSPCs. (B) Heatmap in each panel represents the CTCF ChIP-seq signals within the 2-kb window centered on ChIP-seq peak summits specific to different blood cell types. (C) Genome browser tracks showing an erythroid-dynamic CTCF-binding site (highlighted in pink). (D) Top overrepresented motifs among the dynamic CTCF-binding sites from different types of blood cells. (E) The color chart displays the DNA sequences around the summits of CTCF-bound peaks, aligned with the DNA sequence of core CTCF motif and upstream motifs. Red represents A, blue represents C, green represents T, and yellow represents G. (F) The heatmap represents the ChIP-seq signals within a 2-kb window centered on dynamic CTCF-binding sites and the location of TF binding site motifs in different blood cell types. The DNA segments in each panel are in the same order for each cell type, decreasing from the highest aggregated CTCF ChIP-seq signals within a 2-kb window. The graphs above each heatmap show the aggregated ChIP-seq signal or frequency of matches to motifs. Ery, erythroblast; mono, monocyte.