Sublytic mice develop severe anemia. (A) Morphology of RBCs from a wild-type and sublytic mouse. RBCs were examined after Wright-Giemsa staining, and photographed at a 63× magnification (oil) under light microscopy. (B) BM cells (top panels) and splenocytes (bottom panels) prepared from wild-type and sublytic mice were labeled with Ter119 and CD71 Abs and analyzed by flow cytometry. Values indicate the percentage of cells in each quadrant. (C) Reticulocytes were stained with thiazole orange and counted by flow cytometry. The percentage of reticulocytes in the blood is shown (n = 6 for both wild-type and sublytic mice). (D) Serum erythropoietin was measured by ELISA (n = 3 for both wild-type and sublytic mice). Data represent means ± SEM. (E) Whole spleens from a sublytic homozygous and a wild-type mouse at approximately 9 months of age. (F) Sections of spleens from wild-type and sublytic mice stained with H&E are shown at a 20× magnification. (G) In vivo RBC survival. RBCs were labeled with biotin in vivo by injecting mice with N-hydroxysuccinimide-biotin at 6 weeks of age. The survival of RBCs was followed by measuring the percentage of labeled erythrocytes by flow cytometry.