Minimal defects of hematopoiesis in Sf3b1 heterozygous mice. (A) Quantitative RT-PCR analysis of the expression of Sf3b1 in LSK cells from WT and Sf3b1^+/− mice. Gapdh was used to normalize the amount of input RNA. Data are shown as the mean ± standard deviation (SD) for triplicate analyses. (B) PB cell counts in 20- and 70-week-old WT and Sf3b1^+/− mice. White blood cell (WBC), hemoglobin (Hb), and platelet (Plt) counts are presented as mean ± SD (WT n = 4; Sf3b1^+/− n = 5). (C) The proportion of each cell lineage in PB from 70-week-old WT and Sf3b1^+/− mice shown as mean ± SD (WT n = 4; Sf3b1^+/− n = 5). (D) Absolute numbers of total MNCs, LSK cells, and myeloid progenitors in a unilateral femur and tibia from 70-week-old WT and Sf3b1^+/− mice. Data are shown as the mean ± SD (WT n = 4; Sf3b1^+/− n = 5). (E) Absolute numbers of CD71⁺Ter119⁻, CD71⁺Ter119⁺, and CD71⁻Ter119⁺ erythroblasts in a unilateral femur and tibia from WT and 70-week-old Sf3b1^+/− mice. Data are shown as the mean ± SD (WT n = 4; Sf3b1^+/− n = 5). (F) Percentage of AnnexinV⁺PI⁻ and AnnexinV⁺PI⁺ apoptotic cells in BM LSK cells from 70-week-old WT and Sf3b1^+/− mice. Data are shown as the mean ± SD (WT n = 4; Sf3b1^+/− n = 5). (G) Size of the spleen and the proportion of LSK cells in the spleen from 32-week-old WT and Sf3b1^+/− mice. Data are shown as the mean ± SD (WT n = 5; Sf3b1^+/− n = 5). (H) B-cell differentiation in the BM and proportion of B cells in the spleen from 32-week-old WT and Sf3b1^+/− mice. The proportion of Pro-B (B220⁺CD43⁺IgM⁻), Pre-B (B220⁺CD43⁻IgM⁻), and immature B (B220⁺CD43⁻IgM⁺) and mature B (B220^hiCD43⁻IgM⁺) cells in BM is shown as the mean ± SD (WT n = 5; Sf3b1^+/− n = 5). *P < .05; **P < .01. N.S., not significant.