Central CD150⁺CD48⁻LSK show significantly decreased proliferative potential. (A) Endosteal and central BM was sorted for CD150⁺CD48⁺LSK (R1) and CD150⁺CD48⁻LSK (R2). Fifty cells were cultured in each of 5 wells in serum-free medium supplemented with SCF, IL-6, IL-11, and FL for 6 days and analyzed for total cell number and expression of Sca-1, c-kit, B220, Gr-1, and Mac-1. (B) Number of progeny with Sca-1⁺c-kit⁺Lin⁻, Sca-1⁻c-kit⁻Lin⁻, B220⁺, and Gr-1/Mac-1⁺ phenotypes after 6 days. Lin⁻ is defined as Q1/Q2 (C). Bars represent average of 3 experiments. (C) Representative flow cytometric analysis of cultures. Bottom dot plots are gated for Q1 or Q2, respectively, to exclude Gr-1/Mac-1 and B220 expressing cells. (D) Representative flow cytometric analysis of CD127, CD150, and CD48 expression on endosteal and central LSK and common lymphoid progenitors (CLP). Data are mean ± SEM of 2 experiments.