Xpo7 knockdown inhibits enucleation but does not affect important aspects of erythroid differentiation such as hemoglobin accumulation or the erythroid expression program. (A) (Left) qPCR showing specific knockdown of Xpo7 transcript and (right) western blot showing a decrease in Xpo7 protein for 2 different shRNA constructs. (B) Cell counts counted at 24-hour intervals during in vitro culture of shRNA-infected erythroblasts. (C) Enucleation (left) measured by FACS of cultured erythroblasts using DAPI and TER119 staining (as in Ji et al²¹ ) and (right) quantified for 5 independent experiments. (D) Hemoglobin quantification per cell by spectrometry using Drabkin’s reagent (as in Dessypris¹ ). (E) Transcript levels of erythroid-specific genes as measured by qPCR. Genes chosen are required for (left) hemoglobin production or (right) the process of enucleation. *P < .01 only for mitoferrin-1 (Slc25a37). Complete dataset has been uploaded to the GEO database under accession no. GSE54457; significantly changed transcripts (greater than twofold increase or decrease) are shown in supplemental Table 2.