Phenotype of single-KO and DKO mice. (A) Platelet count and volume for mice of each genotype with mean ± SEM shown. Results analyzed using two-way ANOVA with Tukey’s correction. *P < .01 and **P < .001 compared with WT mice. (B) Representative peripheral blood smear for each genotype showing enlarged platelets (arrowheads) in DKO mice. May-Grünwald-Giemsa stain. (C) Mean ± SEM number of bone marrow megakaryocytes (n = 3 per genotype). Results analyzed using two-way ANOVA with Tukey’s correction. ***P < .0001 compared with WT mice. (D) Representative bone marrow sections with abnormal megakaryocytes (arrowheads arrows) in DKO mice. Hematoxylin-eosin stain. (E) Mean ± SEM for ploidy of freshly isolated megakaryocytes (n = 3 per genotype). fl, femtoliter; hpf, high-power field; MPV, mean platelet volume.