Adult Gata1s mice have a defect in mature erythrocytes. (A) Sulfo-NHS-biotin was injected IV on day 0, and the fraction of biotinylated RBCs was quantified serially by streptavidin labeling and flow cytometry, N = 4. (B) Mice were treated with PHZ solution by intraperitoneal injection on days 0 and 1. Serial HCT of WT and Gata1s (G1s) mice are shown at different time points after induced acute anemia. Normalized recovery was calculated through dividing the HCT mean value at each time point by the mean value at day 0 before treatment. Mean ± SD are shown, N ≥ 3, age = 2 months. ∗∗∗∗P ≤ .0001 by 2-way ANOVA. (C-G) Determination of PB parameters associated with hemolytic anemia, including G6PD activity (C), reactive oxygen species (ROS) levels (D), CD55 and CD59a expression (E), lactate dehydrogenase (LDH) activity (F), and ADA activity (G). ∗P ≤ .05, ∗∗P ≤ .01, ∗∗∗∗P ≤ .0001 by the unpaired Student t test. MFI, mean fluorescence intensity; RFU, relative fluorescence units; PBRBC, peripheral blood red blood cell.