JAK2^V617F and the loss of Ezh2 cooperatively alter transcriptional programs of hematopoiesis. (a) Venn diagrams showing overlaps of up- and down-regulated genes (left and right, respectively) between Ezh2^Δ/Δ, JAK2^V617F, and JAK2^V617F/Ezh2^Δ/Δ LSKs and MEPs isolated 4 wk after the deletion of Ezh2 relative to their WT counterparts. (b) Hierarchical clustering based on total gene expression in LSKs and MEPs isolated from WT, Ezh2^Δ/Δ, JAK2^V617F, and JAK2^V617F/Ezh2^Δ/Δ mice (linkage scores are indicated on the right). (c) A principal component (PC) analysis based on total gene expression in LSKs (open circles) and MEPs (closed circles) isolated from WT, Ezh2^Δ/Δ, JAK2^V617F, and JAK2^V617F/Ezh2^Δ/Δ mice. (d) GSEA plots for Stat5 up-regulated genes defined in human HSPCs comparing mouse LSKs isolated from WT, Ezh2^Δ/Δ, JAK2^V617F, and JAK2^V617F/Ezh2^Δ/Δ mice. (e) Levels of the mean fluorescence intensity (MFI) of phospho-Stat5 (p-Y694) in LSKs from WT, Ezh2^Δ/Δ, JAK2^V617F, and JAK2^V617F/Ezh2^Δ/Δ (n = 3 each) mice after serum starvation (“(−)”) and stimulation of IL-3 (“IL-3”). Bars show the mean ± SEM; three independent experiments. (f) GSEA plots for canonical PRC2 targets defined in LSK HSPCs comparing LSKs isolated from WT, Ezh2^Δ/Δ, JAK2^V617F, and JAK2^V617F/Ezh2^Δ/Δ mice. (g) GSEA for gene expression signatures of HSCs and MkPs comparing LSKs isolated from WT, Ezh2^Δ/Δ, JAK2^V617F, and JAK2^V617F/Ezh2^Δ/Δ mice (the NES, p-value, and FDR q-value [top and bottom rows, respectively] relative to WT LSKs are shown in each cell). (h) GSEA plots for the HSC signature in LSKs isolated from JAK2^V617F/Ezh2^Δ/Δ compared with JAK2^V617F mice. (a–d and f–h) Experiments used cells from two to four mice individual mice per genotype. (d and f–h) The normalized enrichment score (NES), nominal p-value, and false discovery rate (FDR) q-value are indicated.