Loss of HSC numbers in Rs1 mice. Six-week-old (6 wk) and 12-week-old (12 wk) control (Ctrl) and ColI(2.3)+/Rs1+ (Rs1) mice (n = 6-13 per group) were used for these analyses. (A) Gating strategy, (B) frequencies, and (C) total cell numbers for the indicated BM stem and multipotent progenitor cells. (D) Cell cycle analyses. Gating strategy (left) and frequencies (right) of HSCs in G0, G1, and S-G2/M phases of the cell cycle. Lethally irradiated FVB/N-CD45.2 congenic recipients (n = 4 or 5 per group) were transplanted with either (E) 1 × 106 CD45.1 BM cells or (F) 150 CD45.1 purified HSCs together with 300 000 Sca-1–depleted CD45.2 helper BM cells. Transplanted mice were bled every 4 weeks and analyzed for the percentage of donor (CD45.1+) chimerism in the peripheral blood. Data are mean ± SD. *P ≤ .05. **P ≤ .01. ***P ≤ .001.
