Fucosylation-dependent binding of Notch ligands to FX^−/− mice myeloid progenitors. Flow cytometric analysis of binding of recombinant Notch ligands Dll1 (1.3 μg/mL), Dll4 (0.5 μg/mL), Dll3 (0.3 μg/mL), and control (human IgG1 Fc, 1 μg/mL) to CMP cells isolated from WT mice, from FX^−/− mice reared in the presence of fucose, or from FX^−/− mice reared in the absence of fucose. Chelation of Ca²⁺ with ethylenediaminetetraacetic acid abolished binding (data not shown). Data are the flow cytometric histogram of experiment 1 (top panel) and mean fluorescence intensity (MFI) of the binding of CMPs with control and Notch ligands in 3 independent experiments (bottom panel).