PRC2 expression and H3K27me3 during megakaryopoiesis. (A) Gene expression of EZH1 and EZH2 during MK differentiation (n = 3). Data were compared using a t test with Mann-Whitney correction and are shown as mean ± SEM. *P < .05. (B) Protein expression of EZH1 and EZH2 at different days of MK differentiation (i). Actin was used as loading control. Quantification of EZH1 and EZH2 relative to actin using ImageJ software (ii). (C) Three different cell populations (CD41⁺CD42⁺, n = 4; CD41⁺CD42⁻, n = 5; and CD41⁻CD42⁻, n = 4) were sorted at day 9 of culture (top). Microrarrays were performed on each population. Heatmaps showing gene expression of PRC2 components in each population (n = 4) (bottom). (D) H3K27me3 mean fluorescence intensity relative to immunoglobulin G control for each MK population at day 9 of culture (n = 5) (left). Flow cytometry histograms representative of one experiment (right). Data were compared using a Student t test with Mann-Whitney correction. D, day; MFI , mean fluorescence intensity; PPIA, peptidyl-prolyl cis-trans isomerase. All data represent means ± SEM. *P < .05; **P < .005.