Inhibition of erythroid differentiation of Hri^−/− mice during iron deficiency and apoptosis of splenic Ter119⁺ erythroblasts in iron deficiency. (A) Erythroid differentiation of the spleen of Hri^+/+ and Hri^−/− adult mice maintained on a normal diet or an iron-restricted diet. (B) Benzidine-Giemsa–stained cells from sorted P3 and P4+P5 populations. Images were taken with 40× objective using Leitz microscope equipped with Pixelink digital imaging system. (C) Density plots of apoptosis of Ter119⁺ erythroblasts. Splenic Ter119⁺ erythroid cells were gated first. Apoptosis of these cells was then analyzed by their CD71 expression and AnV binding. (D) Quantitation of percentages of AnV⁺ cells in CD71⁺Ter119⁺ cells only. Data are presented as mean ± SD (n = 3 for each group of mice; **P < .01).