Histologic and phenotypic analysis of leukemic mice. (A) H&E-stained histologic sections of liver and spleens infiltrated by leukemic cells in diseased mice. Lower power magnifications, 40×. Higher power magnifications, ×100. Uninfected age-matched TG mouse tissues on the left, and TG MOL4070LTR infected mouse tissues on the right. (B) Immunophenotypic characterization of leukemias in MOL4070LTR-infected WT and TG mouse bone marrow by flow cytometry using the Gr-1 and Mac-1 myeloid markers, CD19 and B220 B-lymphocyte markers, CD90 and CD3 T-lymphocyte markers, Ter119 erythroid marker, and Sca1 and CD117 immature cell markers. (Top) Bone marrow from an uninfected TG mouse. Subsequent panels represent myeloid, lymphoid, and biphenotypic mouse leukemia cases. (C) Immunophenotypic percentages of leukemia/lymphoma in mice infected with the MOL4070LTR retrovirus as determined by flow cytometry. Graphs show percentage of leukemia type as a result of retroviral insertional mutagenesis (for WT n = 21, for TG n = 34). Biphenotypic denotes positive for both myeloid and lymphoid cell markers; and Other, denotesleukemia of immature cell type (only 1 of 21 cases).