Myeloid differentiation potential and responsiveness to the stem cell factors c-kit ligand and thrombopoietin. (A) Clonogenic (□; total cloning frequency) and high proliferative (▪; > 50% of well covered by cells) potentials of single LSKCD34⁺flt3^– and LSKCD34⁺flt3⁺ cells. Mean (SD) values from 3 experiments. (B) Myeloid potentials of single LSKCD34⁺flt3^– (▪) and LSKCD34⁺flt3⁺ (□) cells. Data show the frequencies of cells with granulocyte (G) and macrophage (Mϕ) potentials (means [SD] of 3 experiments). May-Grünwald-Giemsa–stained cultured cells derived from single LSKCD34⁺flt3^– and LSKCD34⁺flt3⁺ cells are shown in lower panels. Images were visualized under an Olympus BX51 microscope equipped with a 100×/1.30 oil objective lens, an Olympus DP70 digital camera, and DP controller 1.1.1.65 software (Olympus, Tokyo, Japan). (C) Frequencies of single LSKCD34⁺flt3^– (▪) and LSKCD34⁺flt3⁺ (▪) cells surviving in response to the stem cell factors KL, TPO, and FL. Mean values (SD) from 3 experiments.