Quantitative analysis of long-term HSC defects in E47-deficient mice. (A) Long-term culture-initiating cell assay was performed with double-sorted flk2− LSKs from WT and E47 KO littermates to determine the frequency of long-term colony-forming cells. Plotted is the percentage of wells that did not give rise to colonies after a single plating (left panel) or serial replating (right panel) at the indicated input cell numbers. The frequency of long-term colony-forming cells was calculated according to Poisson statistics. (B) Limit dilution doses (0.67 × 105, 0.22 × 105, and 0.073 × 105) of CD45.2 WT and E47 KO bone marrow cells mixed with a constant number (2 × 105) of CD45.1 competitor cells were adoptively transferred into lethally irradiated CD45.1+ recipient mice. The graph depicts the percentage of CD45.1 recipient mice that had less than 1% of donor CD45.2+ Gr-1+ cells at 16 weeks after adoptive transfer of the indicated donor cell numbers. The frequency of functional HSCs was calculated using Poisson statistics. Eight recipient mice were used at each cell dose per genotype. **P < .05.
