Abi-1 deficiency results in age progressive increase in circulating granulocytes, anisopoikilocytosis, megakaryocytosis, loss of stainable iron, and fibrosis. (A) Fluorescence-activated cell sorter analysis of CD11b⁺/Gr-1⁺, B220⁺, and CD3⁺ populations in the peripheral blood of Abi-1^WT and Abi-1^KO mice, performed at 14, 35, or 56 weeks of age, 20 Abi-1^WT and 20 Abi-1^KO sex-matched mice were evaluated at each point. (B) Wright staining of representative blood smears obtained from Abi-1^KO and Abi-1^WT mice at 56 weeks of age; teardrop cells are marked with arrows. Similar results were observed in blood smears of at least 12 sex-matched Abi-1^WT or Abi-1^KO mice. Magnification ×100, bars correspond to 20 μm. Images were obtained using a Zeiss Axiophot microscope and Zeiss Pan-Apochromat 100×/1.40 oil lens. Representative (C) hematoxylin and eosin or (D) Prussian blue stains of bone marrow from femurs and spleen sections of 56-week-old Abi-1^WT or Abi-1^KO animals. Similar results were observed in at least 12 sex-matched Abi-1^WT or Abi-1^KO mice. Bars correspond to 100 μm. Images were obtained using a Zeiss Axiophot microscope with Zeiss Pan-Apochromat 20×/1.0 lens. (E) Average number of megakaryocytes per high power field (hpf) and (F) percentage of macrophages with hemosiderin in the bone marrow and spleen/red pulp evaluated in 14-, 35-, and 56-week-old Abi-1^WT or Abi-1^KO animals; 6 sex-matched animals were evaluated per age group per genotype. Representative (G) Gomori reticulin staining of the bone marrow from femurs and spleen sections of 56-week-old Abi-1^WT or Abi-1^KO animals (black stain). Similar results were obtained for at least 12 sex-matched animals per group. Bars correspond to 100 μm. Images were obtained using Zeiss Axiophot microscope with Zeiss Pan-Apochromat 20×/1.0 lens. *P < .05.