Cohesin dosage at active cis-regulatory elements varies between hematopoietic populations during differentiation. (A) Left: diffusion map of scRNASeq expression of Rad21, colored in red with http://blood.stemcells.cam.ac.uk/geneMap.html. The color corresponds to a log2 scale of expression ranging between 0 and the maximum value. LT-HSC, HSPC, and progenitors are highlighted in approximation of the original single-cell sorting. Right: box plots with 10th to 90th percentiles of Rad21 expression in the indicated populations. Erythroid and myeloid progenitors were empirically considered because all the cells with normalized expression of Klf1 > 10 and Spi1 > 10, respectively. (B) Graphical schema of the experimental design to determine cohesin dynamics during normal erythroid and myeloid differentiation. (C) Representative longitudinal flow cytometry plots. HPC were differentiated toward the erythroid and myeloid lineages. Day 2 of EPO induction was highlighted as the optimal erythroid (or Ery) transition state, whereas cells induced for 3 days with IL-3 were called myeloid (or myelo) transition cells. (D) Density heat map and (E) average profiles of Rad21 binding at cohesin-associated regions in the indicated cellular states. (F) Total count of significant differentially bound Rad21 peaks comparing HPC to the indicated differentiation lineage. Left panels show pie charts of genomic location of differential bound peaks. Scatter plots (right): differential Rad21 binding at active promoters/enhancers in the indicated populations. Blue dots (lost) show peaks that decrease, whereas red/purple dots (gained for erythroid and myeloid cells respectively) show peaks that increase during differentiation. LT, long term.