Loss of HSCs has little effect during the normal lifespan of mice. (A) Experimental design of Moz deletion in situ. (B) Quantification of Moz^fl alleles in nucleated cells of the peripheral blood by qPCR from 100 to 558 days after poly(I:C) treatment of Moz^fl/fl;Mx1-cre (n = 5) and Moz^fl/fl (n = 6) control mice. No significant change in the level of Moz-deleted alleles was seen over this period (P = .9775). (C) Peripheral blood analysis of mice 18 months after poly(I:C) treatment of (n = 9) Moz^fl/fl;Mx1-cre and (n = 9) Moz^fl/fl control mice (complete analysis; supplemental Figure 4). The erythrocyte (RBC) and neutrophil counts were normal. Note the reduction in leukocytes (white blood cells [WBCs]), due to a reduction in lymphocytes (predominantly B cells; supplemental Figure 6). (D) Experimental design of chimeric transplantation first and then Moz deletion 90 days later. The bone marrow from each donor Moz^fl/fl;Mx1-cre (n = 3) and control Moz^fl/fl (n = 3) mouse was transplanted into 3 recipients together with wild-type CD45.1 bone marrow, as indicated. (E) Percentage of CD45.2-positive Moz^fl/fl;Mx1-cre, and Moz^fl/fl control cells in peripheral blood changes over time in the presence of wild-type competitors. Data are presented as the mean ± SEM.