C/EBP induces terminal differentiation of 32D cl3 myeloblasts in IL-3. (A) Total cellular protein extracts derived from a 32D cl3 subclone transduced with a control retrovirus (32D-Puro) and from two 32D cl3 subclones transduced with a retrovirus expressing C/EBPWT-ER (32D-WT-ER-1 and 32D-WT-ER-2) were subjected to Western blotting using an antisera specific for C/EBP. The location of C/EBPWT-ER is indicated. (B) 32D-WT-ER-1 cells in IL-3 were exposed to 1 μmol/L estradiol. Cytospins were prepared before estradiol addition (E0) and 1, 2, and 3 days later (E1, E2, and E3) and were subjected to Wright’s-Giemsa staining. (C) 32D-Puro and 32D-WT-ER-1 cells in IL-3 were exposed to estradiol. For each culture, total cellular RNA was prepared after 0, 1, 2, 3, or 4 days in estradiol. These RNAs were then subjected to Northern blotting for MPO, G-CSF receptor (GCSFR), and 18S RNAs. (D) 32D-WT-ER-2 cells in IL-3 were exposed to estradiol, and total cellular RNA was prepared after 0 hours, 4 hours, 8 hours, 1 day, 2 days, 3 days, or 4 days in estradiol. These RNAs were then subjected to Northern blotting for MPO, lactoferrin (LF), or 18S RNAs.