C/EBPα-ER favors monocytic morphologic development. (A) Diagram of C/EBPα-ER and 3 mutant variants. TAD indicates transactivation domain; BR, basic region; LZ, leucine zipper; GZ, GCN4 leucine zipper; ER, estradiol receptor ligand-binding domain. (B) Western analysis of each variant 2 days after culture of lineage-depleted, transduced marrow cells with or without E₂, detected with ER antiserum (top). Western blot of C/EBPα-ER and endogenous C/EBPα, without E₂ on D0 and D2, detected with C/EBPα antiserum (bottom left). Detection of C/EBPα-ER in low versus high GFP cells after transduction with MIGR1-C/EBPαER, using ER antiserum (bottom right). (C) Marrow cells transduced with pBabePuro-C/EBPαER (αER) pBabePuro-C/EBPαBR3 (BR3), lineage-depleted and then cultured with or without E₂ for 2 days were visualized by Wright-Giemsa staining. The differentials obtained from counting 100 cells per culture are shown below the micrographs. %Gran includes granulocytes, bands, metamyelocytes, myelocytes, and promyelocytes. %Mono represents the number of monocytes.