Expression of myelo-E lineage programs and Notch-target genes in Rbpj-deficient E and Mk progenitors. (A-D) E and Mk progenitor subsets were purified from individual 10- to 12-week-old Rbpj^fl/flMx1^Cre/+ (N = 6) and age-matched Rbpj^fl/flMx1^+/+ (N = 2) and Rbpj^fl/+Mx1^Cre/+ (N = 2) poly(I:C)-treated control mice and subjected to quantitative gene expression analysis for (A,C) erythroid and (B-C) megakaryocytic-related genes and (D) Notch1 and Notch2 receptors. Mean (SEM) values normalized to Hprt. No differences between Rbpj^fl/flMx1^Cre/+ and control mice reached statistical significance. (E) BM HSCs, Mk, and E progenitor cells (100 cells per replicate) were purified from individual 8-week-old RbpJ^fl/flVav^Cre/+ (N = 5) and age-matched RbpJ^fl/flVav^+/+ or RbpJ^fl/+Vav^Cre/+ controls (N = 1 and 2, respectively) and analyzed for expression of the Notch target genes Hes1, Hes5, Nrarp, and Gata3. Mean (SEM) values. Samples in which the mean value of replicates was ≤0.001 (relative to Hprt expression) were considered below cutoff value (#). For all data sets (A-E), statistical significance was investigated between Rbpj-deleted and control mice. *P < .05; **P < .01. See also supplemental Figure 1H.