Loss of PHD2 in LSK cells leads to MPP self-renewal under steady-state conditions. (A) LSK cells were isolated from WT and CD68:cre-PHD2^f/f (cKO) mice and tested for the presence of PHD1, PHD2, and PHD3 mRNA (n = 4-7). (B-C) Absolute cell number of (B) total BM and (C) LSK cells in the BM of WT and cKO littermates (n = 6). (D-E) Using 7-color flow cytometry, LSK BM can be subdivided into 5 populations based on differential expression of CD34, CD150, CD48, and CD135. The CD150⁺48⁻135⁻ subset can be divided into (1) CD34⁻ (HSC) and (2) CD34⁺ (MPP1) subsets. The CD150⁺48⁺ subset is almost exclusively (3) CD34⁺CD135⁻ (MPP2), and the CD150⁻CD48⁺ subset can be divided into (4) CD135⁻ (MPP3) and (5) CD135⁺ (MPP4) subsets. Percentages on FACS histograms are from a typical WT and cKO mouse. (F) The absolute numbers of the 5 LSK subsets (HSC/MPPs) in the BM of WT mice and their cKO littermates (n = 6). All data are mean ± SEM. *P < .05; ***P < .005. Abs. cell n°, absolute cell number.