Analysis of engraftment of HW80 hosts from experiments 2 and 3 receiving tertiary transplants of wild-type, STAT5ab^-/-, or c-Mpl^-/- BM cells. BM cells harvested from 2 wild-type C57BL/6 (Hb_s) and 2 STAT5ab^-/- (Hb_s) mice were serially transplanted into lethally irradiated HW80 recipients (Hb_d) for both experiment 2 (A) and experiment 3 (B). Twelve weeks following tertiary transplantation, mice were bled, and the red blood cells were analyzed by hemoglobin electrophoresis for the relative contribution of Hb_s and Hb_d to the peripheral blood engraftment. In addition to the STAT5ab^-/- and wild-type BM grafts, experiment 3 also included mice receiving c-Mpl^-/- BM cells collected from 2 donor mice. Shown on the right of all sets of gels are positive controls for the Hb_s and Hb_d bands. The %Hb_s for each individual mouse is shown below each lane.