Expression profile of Vav1-driven Cre-mediated recombination. Flow cytometric analysis of recombination status of RosaGFP locus in CD41⁺ definitive hematopoietic progenitors from E9.5 yolk sac (right column) and CD45⁺ adult peripheral blood leukocytes (left column). As a negative control, a Vav1Cre nontransgenic (NTG) ROSA heterozygous mouse is presented in the top row. The mean fluorescence intensity (MFI) of the GFP channel is depicted in each panel. Data are representative of 3 independent specimens analyzed for each genotype (N = 3).