Fig. 3.

Premature clearance of mitochondria and impaired CD71 shedding only in KO reticulocytes, not erythroblasts. a Reduced mitochondrial membrane potential in the bone marrow erythroblasts and peripheral reticulocytes of IEX-1 KO mice. Ter119⁺CD71⁺ cells in the bone marrow (erythroblasts, left panels) or peripheral blood (reticulocytes, right panels) were stained with MitoTracker and JC1 to detect mitochondrial content and membrane potential, respectively. The mean fluorescence intensity (MFI) of MitoTracker and JC1 (red J-aggregate) was analyzed by flow cytometry and presented as mean ± SEM. ns no significance. *P < 0.05 and ***P < 0.001 compared with WT group. b Enhanced clearance of mitochondria by autophagy in KO reticulocytes. Young reticulocytes were matured ex vivo as in Fig. 2d and analyzed by transmission electron microscopy at indicated days: intact mitochondria, blue arrows; mitochondria phagocytosed by autophagosomes, red arrows; scale bar, 1 μm. c Effects of FCCP and wortmannin on mitochondrial clearance and CD71 shedding in WT and KO reticulocytes. Ter119⁺CD71^high reticulocytes were cultured in the presence of 10 μM FCCP or 100 nM wortmannin, followed by flow cytometric analysis of mitochondria and CD71 at indicated days. Data were representative for at least 12 samples per group in all relevant panels