Figure 2.

Ablating Lrp5 and -6 compromises HSC functions. A) CFU-Spleen₁₂ assays. 1 × 10⁵ BM cells isolated from WT, Lrp5KO, -6KO, and dKO mice were injected into irradiated recipients. After 12 d, spleens from recipients were harvested and colonies were counted. B) Experimental design for competitive repopulation assay. Whole BM cells from test (CD45.2⁺) and competitor (CD45.1⁺) were mixed at a 1:1 ratio and transplanted into irradiated recipients. The contributions to PBCs were analyzed at 8 and 16 wk post-transplantation. C, D) Representative pseudocolor plots (C) and cumulative data (D) are shown (n ≥ 4). E) Experimental design for serial transplantation assay. 2 × 10⁶ BM cells from test mice (CD45.2⁺) were transplanted into irradiated primary recipients (CD45.1⁺). After 16 wk, BM cells from the primary recipients were transplanted into secondary recipients (CD45.1⁺), and this process was repeated to obtain quaternary recipients. The contributions to PBCs from original donors were determined at 16 wk after each transplantation. F, G) Representative pseudocolor plots (F) and cumulative data (G) are shown. Data are representative of at least 2 independent experiments (mean ± sd) (n ≥ 7). *P < 0.05, **P < 0.01 by Student’s t test.