Activation of PU.1 antisense transcription during early lymphopoiesis. (A) Schematic of PU.1 locus: AsPr (red arrow box), PrPr (blue arrow box), asRNA (red line), coding mRNA (blue line), and −17 kb enhancer (URE, gray box). (B) Human hematopoietic cell differentiation hierarchy. (C) Aligned reads from ATAC-seq of PU.1 locus during myelopoiesis. (D) URE-adjusted peak quantification values for AsPr and PrPr by ATAC-seq (upper panel, purple and steel blue respectively) and PU.1 asRNA and mRNA (red and blue, respectively) transcript profile (lower panel) for each population during myelopoiesis (population, replicates for ATAC-seq/RT-qPCR; hematopoietic stem cell and multipotent progenitor [HSC-MPP], n = 13/9; common myeloid progenitor [CMP], n = 8/8; granulocyte-macrophage progenitor [GMP], n = 7/9; megakaryocyte-erythroid progenitor [MEP], n = 7/10; monocyte, n = 6/6). (E) Aligned reads from ATAC-seq of PU.1 locus during lymphopoiesis. (F) URE-adjusted peak quantification values for AsPr and PrPr by ATAC-seq and PU.1 asRNA and mRNA transcript profile for each population during lymphopoiesis. Ratio of AsPr to PrPr (yellow) and asRNA to mRNA (brown) for each population in myelopoiesis (G) and lymphopoiesis (H). (I) Correlation analysis of promoter chromatin accessibility ratios to transcript expression ratios. Regression line with Pearson correlation coefficient. Promoter and transcript ratio analysis in bone marrow hematopoietic progenitors for AsPr/PrPr chromatin accessibility ratio (J) and asRNA/mRNA transcript expression ratio (K). Data are represented as mean ± standard error of the mean. *P < .05, **P < .01, ***P < .001, Wilcoxon test. CLP, common lymphoid progenitor; Erythr., erythrocyte; Gran., granulocyte; LMPP, lymphoid-primed multipotent progenitor; Mono., monocyte; Plat., platelet.