Redundant roles of Zfp148 and Zfp281 in primary murine fetal liver erythroid cells. (A) Western blot showing knockdown of murine Zfp281 protein levels in MEL cells transduced with lentiviral shRNA constructs shZfp281c#3, zhZfp281c#4, and shLuc. (B) Schematic diagram showing an experimental timeline of ex vivo culture, lentiviral transduction, and puromycin selection of fetal liver cells. (C) Representative benzidine stains with May-Grünwald counterstain of cytospun cells from murine e12.5-e13.5 d.p.c. Zfp148^−/− or WT (littermates) fetal liver cells transduced with the indicated shRNA lentiviruses, selected with puromycin, and ex vivo differentiated into erythroid cells (8 days in expansion medium followed by 48 hours in differentiation medium; see “Methods”). Magnification ×600. (D) Bar graph shows blinded benzidine counts from 5 biologic replicates of cultures in panel C. (E-F) Representative CD71/Ter119 flow cytometric plots and quantitation of the cultures in panel C. Each plot shows the percentage of R1 to R5 populations in 5 biological replicates. *P < .05; **P < .01.