Iron deficiency anemia is accompanied by thrombocytosis in mice. (A-E) Blood cell counts were performed in females fed with an AI or ID diet for 9 weeks followed by 2 weeks of pregnancy (n = 3 for each condition). (F) Platelet (PLT) count by flow cytometry normalized to the total combined platelet and RBC count by automated cell counter in the same females fed with an AI or ID diet (n = 3/condition). (G-K) Blood cell counts were performed in 8- to 10-week-old male and female Tmprss6^−/− and WT littermate controls (n = 7/genotype). (L) Platelet count by flow cytometry normalized to the total combined platelet and RBC count in the same 8- to 10-week-old male and female Tmprss6^−/− and WT littermate controls (n = 7/genotype). (M) Flow cytometric analysis of the frequency of megakaryocytes (CD41⁺ cells) in the BM of Tmprss6^−/− and WT littermate controls (n = 3 WT, n = 6 Tmprss6^−/−). (N) Representative histograms of flow cytometric analysis of megakaryocyte ploidy in the BM of Tmprss6^−/− and WT littermate controls. (O) MFI of propidium iodide (PI) in CD41⁺ cells (n = 3 WT, n = 6 Tmprss6^−/−). Data are presented as mean + SD. *P < .05, **P < .01, ***P < .001, and ****P = .0001 calculated by 2-tailed unpaired Student t test.  Hb, hemoglobin; HCT, hematocrit; MCH, mean corpuscular hemoglobin; MCV, mean corpuscular volume.