Ectopic expression of NFI-A blocks granulocytic (G) differentiation of HPCs. (Ai) Growth curve of unilineage G cultures transduced with vector or NFI-A lentivirus (mean ± SEM values of 3 independent experiments). (ii) The histogram shows the percentage of viable (or 7-amino-actinomycin D-negative) cells detected by flow cytometry (representative of 3). (iii) Wright-Giemsa staining of infected cells, showing the percentage of cells at various stages of differentiation. A representative experiment of 3 is shown. (Bi) Real-time PCR analysis of G-CSFR mRNA and (ii) flow cytometry analysis of total G-CSFR protein expression in vector and NFI-A cells at day 8. (C) Flow cytometry analysis of (i) CD11b and (ii) CD14/CD15 myeloid markers at day 10. (D) (Left) number of CFU-G colonies generated by transduced HPCs (mean ± SEM values; n = 3). (Right) Representative microphotographs of G colony or cluster in vector or NFI-A culture, respectively, at day 14. Original magnification ×100. See “Morphologic analysis” for more image information.