Defect of erythropoiesis in Gata1s adult mice. (A-B) PB indices for WT, Gata1s heterozygous (Het) females, Gata1s homozygous females (F), and Gata1s hemizygous males (M) between 2 and 20 months of age. N_{WT M} ≥ 10, N_{G1s M} ≥ 10, N_{WT F} ≥ 4, N_{Het F} ≥ 7, N_{G1s F} ≥ 5. ∗∗∗P ≤ .001, ∗∗∗∗P ≤ .0001 by 2-way analysis of variance (ANOVA). (C) Erythropoietin (EPO) levels in the PB of 2-month-old animals. N_wt = 7, N_G1s = 8. ∗∗P ≤ .01 by the unpaired Student t test. (D) Representative flow cytometry plots and bar graph of mean ± standard deviation (SD for erythroid cells in the PB of Gata1s (G1s) mice as assessed by staining with antibodies against Ter119 and CD71. N_wt = 3, N_G1s = 4. (E) Photos (left) and quantitation (right) of reticulocytes in the PB of WT and Gata1s littermates (2 months old). In panel E, scale bars represent 25 μm. The graph depicts the percentage of reticulocytes in 5 fields. N = 5. ∗∗P ≤ .01 by the unpaired Student t test. n.s., not significant.