The reduced PIGA^- RBC survival is independent of complement. RBCs from FL mice with about 50% of PIGA^- RBCs were stained with PKH26 and injected into the tail vein of wt or complement-deficient host mice. Proportion of PKH-stained PIGA^- and PIGA⁺ RBCs was monitored by flow cytometry. (A) PIGA-RBCs after transfusion into wt recipient mice. (B) PIGA^- RBCs after transfusion into mice deficient in the complement component C5, (C) C4, (D) factor Bf, or (E) C3. The percentage of stained PIGA^- and PIGA⁺ cells was determined for each time point and normalized to 2 hours after injection time point. Data represent mean ± SD. (F) The proportion of reticulocytes (Retics) in the PIGA^- RBC population and PIGA⁺ population in FL wt mice and FL mice additionally deficient for complement component Bf, C3, C4, and C5. In all animals the proportion of reticulocytes was higher within the PIGA^- cells compared with the proportion of reticulocytes in the PIGA⁺ RBCs, indicating that in all mice PIGA^- RBCs have a shortened half-life in circulation. (G) The survival of DAF^-/- RBCs compared with simultaneously infused 100% PIGA^- RBCs showed a shorter survival of PIGA^- RBCs. (H) The survival of DAF^-/- CD59a^-/- RBCs compared with simultaneously infused 100% PIGA^- RBCs showed a shorter survival of PIGA^- RBCs. The percentage of stained PIGA^- and PIGA⁺ cells was determined for each time point and normalized to 2 hours after injection time point. Data represent mean ± SD.