Effects of Ezh2 deletion on the development of MF in Jak2V617F mice are cell autonomous. (A) Experimental design for cell autonomous BMT assay. BM cells (1 × 10⁶) were harvested from control, Jak2^VF/+, and Jak2^VF/+ Ezh2^−/− mice at 12 weeks after pI-pC injection and transplanted into lethally irradiated wild-type C57BL/6 recipient mice. (B) Kaplan-Meier survival analysis of transplanted animals receiving bone marrow from control (n = 8), Jak2^VF/+ (n = 8), and Jak2^VF/+ Ezh2^−/− (n = 8) mice (**P < .005 by log-rank test). (C) Peripheral blood RBC, hematocrit (HCT), WBC, and platelet (PLT) counts were measured in recipient animals receiving control (n = 8), Jak2^VF/+ (n = 8), and Jak2^VF/+ Ezh2^−/− (n = 9) BM at 4 and 8 weeks after BMT. (D) Flow cytometric analysis of erythroid precursors using Ter119 and CD71 surface markers in the BM and spleens of recipient mice at 8 to 10 weeks after transplantation. Representative dot plots are presented (upper). Percentages of erythroid precursors (stages I-IV, from immature to mature) are shown in bar graphs (lower) as mean ± SEM (control, n = 8; Jak2^VF/+, n = 8; Jak2^VF/+ Ezh2^−/−, n = 7). (E) Representative dot plots (upper) and bar graphs (lower) showing percentages of megakaryocytic precursors (CD41⁺CD61⁺ and CD41⁺) in the BM and spleens of recipient mice. The data are presented as mean ± SEM (control, n = 8; Jak2^VF/+, n = 8; Jak2^VF/+ Ezh2^−/−, n = 7). (F) Peripheral blood smears (×1000 magnification) from the BMT control, Jak2^VF/+, and Jak2^VF/+ Ezh2^−/− mice at 8 weeks after transplantation are shown in the upper panels. Reticulin staining of representative BM sections (×500 magnification) from control, Jak2^VF/+, and Jak2^VF/+ Ezh2^−/− BM recipient mice at 8 weeks after BMT are shown in the bottom panels. One-way ANOVA was used for comparisons of all 3 groups of mice, and the Student t test was used to compare between 2 groups of mice (*P < .05; **P < .005).