Excess megakaryopoiesis in Cul5^fl/flVavCre mice. Numbers of (A) platelets (n = 21–24) and (B) megakaryocytes per field (n = 5–8) from histological sections of sternal BM from Cul5^fl/flVavCre and Cul5^fl/fl, Cul5^+/+ and Cul5^+/+VavCre control mice. Numbers of (C) MkP (Lin⁻Sca1⁻Kit⁺CD150⁺CD41⁺, n = 6-12) and (D) HSC (Lin⁻Sca1⁺Kit⁺CD150⁺CD48⁻), multipotent progenitor (MPP) cells (Lin⁻Sca1⁺Kit⁺CD150⁻CD48^lo/−), HPC1 (Lin⁻Sca1⁺Kit⁺CD150⁻CD48⁺), HPC2 (Lin⁻Sca1⁺Kit⁺CD150⁺CD48⁺), HPC1Flt3^hi and HPC1Flt3^lo cells (top panel, n = 4-17), and common myeloid progenitor (CMP) (Lin⁻Sca1⁻Kit⁺CD34⁺ FcγRII/III^lo), granulocyte-macrophage progenitor (GMP) (Lin⁻Sca1⁻Kit⁺CD34⁺ FcgRII/III⁺), megakaryocyte-erythroid progenitor (MEP) (Lin⁻Sca1⁻Kit⁺CD34⁻FcgRII/III⁻) and colony-forming erythroid (CFU-E) (Lin⁻Sca1⁻Kit⁺CD150⁻Endoglin^hiFcγRII/III^lo) (lower panel, n = 4-17) in Cul5^fl/flVavCre and Cul5^fl/fl, Cul5^+/+ and Cul5^+/+VavCre control mice. Each point is data from an individual mouse, bars represent mean ± standard deviation (SD). ∗∗P < .01, ∗∗∗∗P < .0001 for comparison of data from Cul5^fl/flVavCre mice with that of control genotypes (1-way analysis of variance [ANOVA] with Dunnett correction for multiple comparisons).