Stromal cell heparan sulfate controls HSPC localization in the BM. (A) Schematic overview of the breeding strategy to facilitate prospective isolation of CD45⁻ Ter119⁻ Mx1⁺ cells. Control and mutant mice were bred into a Rosa-YFP strain. (B) BM analysis showing contribution to CD45⁻ Ter119⁻ Mx1⁺ CD105⁺ CD140⁺ Sca1⁺ stromal stem cells in control and mutant mice. (C) Schematic overview of experimental design. (D-H and Figure 2A-H) Data collected 24 weeks after pIpC induction. (D-F) BM analysis showing (D) contribution to B cells (B220), myeloid cells (Mac1 and Gr1), and T cells (CD3); (E) committed myeloid (CMP, GMP, and MEP) and common lymphoid progenitors; and (F) to LKS CD48⁻CD150⁺ HSCs. (G) Apoptosis in the BM KLS CD48⁻CD150⁺ cell population. (H) Cell cycle analysis of BM KLS CD48⁻CD150⁺ HSCs; cells in G0, G1, and S-G2-M phases of the cell cycle are shown. CMP: Lin⁻cKit⁺Sca1⁻CD34⁺CD16/32⁻; GMPs: Lin⁻cKit⁺Sca1⁻CD34⁺CD16/32⁺; MEPs: Lin⁻cKit⁺Sca1⁻CD34⁻CD16/32⁻; common lymphoid progenitors: Lin⁻cKit^lowSca1^lowCD127⁺. Data are representative of at least 3 independent experiments; n = 5 to 8 mice per genotype per experiment. Data are represented as mean ± SD. * P < .05; ** P < .01. Ctrl, control; KO, knockout.