K3 is a constituent of erythrocyte junctional complexes, and its deficiency results in poikilocytosis and macrocytosis. (A) Representative images of mouse peripheral blood smears stained with Wright-Giemsa stain. Images were captured with ImageEM C9100-13 EMCCD monochrome camera using a Leica DMI6000 microscope equipped with an oil 40×/1.15 objective and LAS-X software. The images were processed with the Adobe Photoshop 7.0 software. Scale bar, 10 μm. (B) (left) Representative histograms of RBC volume and Hb concentration obtained via an automated complete blood count analysis of K3WT and K3KO/EpoR-cre peripheral blood with an Advia 120 Hematology System; right) the histograms from the left panel plotted as a RBC volume/hemoglobin concentration cytogram, normal K3WT RBCs fall into the central square. (C-F) Statistical comparison of MCV (C), MCHC (D), RDW values (E), and reticulocyte percentages (F) of K3WT and K3KO/EpoR-cre peripheral blood RBCs. ∗P < .001; K3KO∖EpoR-cre vs K3WT mice; n = 7 to 10 mice per group. (G) K3 forms complexes with proteins of erythrocyte junctional complexes. Western blot analysis of proteins coimmunoprecipitated with anti-K3 Ab from lysates of K3WT erythrocyte ghosts. MCHC, mean corpuscular hemoglobin concentration; MCV, mean corpuscular volume; RDW, RBC distribution width.