Defective erythropoiesis in Fak^−/− mice during PHZ-induced anemia. WT and Fak^−/− mice were treated with PHZ (100 mg/kg at day 0). At the indicated time points, hematocrits (A), spleen weight (B), splenic cellularity (C), photomicrographs of spleen (D), flow cytometry based analysis of the frequency (percentage) of Ter119/CD71 positive erythroblasts (R3, R4, and R5) in the spleen (E), absolute number of Ter119/CD71-positive erythroblasts in the spleen (F), absolute number of erythroid burst-forming units and erythroid colony-forming units in the spleen (G), frequency (percentage) of Ter119/CD71-positive erythroblasts (R3) in the BM (H), and percent of Ter119/CD71-positive erythroblasts in the BM were assessed (I). For each analysis, mean ± SEM are illustrated (n = 3 mice per group, 2 independent experiments were performed; *P < .05). (J) Cre-mediated deletion of Fak was detected in BM and spleen after 8 days of PHZ treatment as a 327-bp fragment. WT allele of Fak was detected as a 1.6-kb fragment. Lanes 1, 2, and 3 represent WT Fak bands after 8 days of PHZ treatment in BM and spleen, respectively. Lanes 4, 5, and 6 show Fak deletion in BM and spleen after 8 days of PHZ treatment, respectively.