Increased marrow BFU-E frequency and enhanced responsiveness to anemic challenge in HDAC5^−/− mice. (A) Colony-forming progenitor frequencies in marrows of adult WT and HDAC5^−/− (KO) mice. Data are mean ± SEM (n = 3/group). (B) Marrow cellularity in adult WT and HDAC5^−/− mice (n = 4/group). (C) RBC and Hb levels in animals before and after anemia induction. HDAC5^+/+ and HDAC5^−/− mice received PHZ on days −1 and 0. Data are mean ± SEM (n = 7/group). **P < .001. *P = .017. ##P < .0001. #P = 0.003. (D) Staining for iron deposition in HDAC5^+/+ and HDAC5^−/− spleens on day 13 after anemia induction. Shown are light microscope images (original magnification × 200) representative of findings in all animals studied (3/group). Images were acquired using an Olympus BX51 microscope equipped with an Olympus DP70 digital camera. The objective lens consisted of Uplan Fl 20×/0.75 NA. Image acquisition and processing were used: Adobe Photoshop, CS3/10.0 and CS2/9.0, respectively.