Fig. 3.
Flow cytometry results showing the stages of erythroid precursor maturation at which apoptosis occurred in a control subject at Stanford University and 2 patients (A and B) with β0-thal/HbE.
Forward scatter (ForSc), an index of cell size, is shown on the ordinate, whereas the number of dead and apoptotic erythroid precursors, as determined by annexin V reactivity (AnV-FITC), is plotted on the abscissa (vertical line). The horizontal lines indicate the sites of the stages of erythroid maturation. Proerythroblasts and basophilic erythroblasts (Pro-Baso) are the largest, polychromatophilic erythroblasts (Poly) are somewhat smaller, and orthochromic erythroblasts (Ortho) are the smallest. The shaded area indicates the major apoptotic erythroblast population in each subject.