Figure 4. Defective stem cell function in U2af1-deficient mice.

(a) Competitive reconstitution assay. BM cells (5×10⁵) from uninduced CD45.2⁺ Mx1Cre;U2af1fl/fl (U2af1 cKO) or littermate control mice were mixed with CD45.1⁺ wild type mice BM (5×10⁵) at a 1:1 ratio and transplanted into lethally irradiated CD45.1⁺ recipient mice. Four weeks after BMT, recipient mice were treated with 3 doses of pI-pC to induce U2af1 deletion after hematopoietic reconstitution. The recipient mice were analyzed at 16 weeks after pI-pC injection. (b) The percentages of donor-derived CD45.2⁺ cells, (c) percentages of CD45.2⁺ Gr-1⁺ myeloid cells (d) percentages of CD45.2⁺ B220⁺ B cells and (e) percentages of CD45.2⁺ Tcrβ⁺ T cells in the peripheral blood of recipient animals at 2 and 16 weeks after pI-pC induction are shown in bar graphs. (f) Representative contour plots of flow cytometric analysis and the percentages of donor-derived CD45.2⁺ total BM cells, (g) percentages of CD45.2⁺ Gr-1⁺ myeloid cells and (h) percentages of CD45.2⁺ LSK cells in the BM of recipient animals at 16 weeks after pI-pC induction are shown; bar graphs represent mean ± SEM. (Control, n=10; U2af1 cKO=10). Student t-test was used to compare between two groups of mice (**p<0.005, ***p<0.0005 and ****p<0.00005).