C/EBPα binds the promoter or transcriptional start site of many genes needed for transition from MPP to CDP. (A) Array data from C/EBPα^−/− MPPs were compared with that of CDPs, whereas differences between normal MPPs and CDPs were subtracted from this analysis, uncovering genes that are located in the shaded section of the Venn diagram. The most differentially up- and downregulated genes while transitioning to CDP are presented in the right two panels. (B) Expression of C/EBPα, C/EBPβ, PU.1, IRF4, IRF8, Klf4, Id2, and RelB by relative quantitative RT-PCR of RNA from sorted CMPs (cKit^Hi, Sca1⁺, Lin^– CD34⁺ FcγRII/III^lo/–); white bars represent controls and black bars represent floxed progenitors. Values normalized to the control, nonexcised flox CMPs, except with RelB where samples were normalized against the floxed deleted sample. Data are averages of 3 independent experiments (error bars represent SEM). (C) Lin^– cKit⁺ progenitors were sorted from the bone marrow of control or C/EBPα floxed mice. Cells were double-sorted from each group and used for Western blot analysis to determine transcription factor expression compared with HSP-90 (bottom panel). (D) C/EBPα ChIP-seq of CMPs was analyzed for specific genes important during DC differentiation. Plots show ChIP-fragment density at each position in the regions of the genes PU.1, Relb, Gfi1, Klf4, C/EBPβ, Irf8, and Irf4. ChIP-seq profiles are given for genes that were considered altered from (B) and (C). (E) Relative quantitative RT-PCR of transcripts, isolated from EML-ER and EML-C/EBPα-ER, were measured from cell lines cultured for 24 hours with 4-HT to assess expression of PU.1, RelB, Gfi1, Klf4, Irf8, and Irf4. The y-axis indicates the relative expression of the transcription factor relative to that of control treated EML. Data are averages of 2 independent experiments (error bars represent SD).