Homogeneous mast cell phenotype of populations generated from single BCR-ABL–transduced +/+ and IL-3^−/− cells.

(A) FACS profiles from a representative clonal population of expanded BCR-ABL–transduced +/+ cells are shown. All cells express Ly 5.2, GFP, Sca-1, and c-kit, and bind IgE, but do not express Gr-1, Mac-1, B220, CD4, CD8, or the antigen recognized by Ter119. Similarly derived expanded clones of BCR-ABL–transduced IL-3^−/− cells showed an indistinguishable phenotype. (B) Wright-Giemsa–stained cytospin preparations from representative clones of BCR-ABL–transduced +/+ cells (left panel), BCR-ABL–transduced IL-3^−/− cells (middle panel), and BCR-ABL– and IL-3–cotransduced IL-3^−/− cells. All of the cells in all cultures examined exhibited this typical mature mast cell morphology.