Summary of the β-Globin mRNA Content, the Epo-Dependent Cell Growth, and the Epo Binding Capacity of G418rClones of Ba/F3 Cells Transfected With an EpoR Expression Plasmid
| Clone . | β-Globin mRNA . | Epo-Dependent Growth . | ||||
|---|---|---|---|---|---|---|
| . | −Epo . | +Epo . | Cells/mL ×10−5 . | Fold Increase . | 125I-Epo Binding . | |
| . | . | . | d 0 . | d 2 . | . | (cpm/3 × 106 cells) . |
| G-1 | ++ | ++ | 1.2 | 6.83 | 5.7 | 2,740 |
| G-2 | + | + | 1.2 | 8.66 | 7.2 | 7,250 |
| G-3 | − | − | 1.2 | 11.6 | 9.7 | 5,740 |
| G-4 | +++ | +++ | 1.2 | 14.3 | 11.9 | 5,380 |
| E-1 | − | ± | 0.44 | 5.23 | 11.9 | 6,540 |
| E-2 | − | − | 0.41 | 9.88 | 23.9 | 8,540 |
| E-3 | ++ | +++ | 0.35 | 8.63 | 24.3 | 6,920 |
| E-4 | − | − | 0.46 | 9.55 | 21.0 | 15,600 |
| E-5 | − | NM | 0.44 | 0.50 | 1.1 | 830 |
| E-6 | − | − | 0.48 | 1.70 | 3.5 | 2,160 |
| E-7 | ± | +++ | 0.46 | 5.63 | 12.2 | 5,930 |
| E-8 | − | NM | 0.47 | 0.38 | 0.8 | 770 |
| E-9 | − | NM | 0.34 | 0.52 | 1.5 | 1,600 |
| E-10 | ++ | +++ | 0.31 | 6.55 | 21.2 | 5,610 |
| E-m | − | ± | 0.52 | 6.86 | 13.1 | 6,670 |
| Clone . | β-Globin mRNA . | Epo-Dependent Growth . | ||||
|---|---|---|---|---|---|---|
| . | −Epo . | +Epo . | Cells/mL ×10−5 . | Fold Increase . | 125I-Epo Binding . | |
| . | . | . | d 0 . | d 2 . | . | (cpm/3 × 106 cells) . |
| G-1 | ++ | ++ | 1.2 | 6.83 | 5.7 | 2,740 |
| G-2 | + | + | 1.2 | 8.66 | 7.2 | 7,250 |
| G-3 | − | − | 1.2 | 11.6 | 9.7 | 5,740 |
| G-4 | +++ | +++ | 1.2 | 14.3 | 11.9 | 5,380 |
| E-1 | − | ± | 0.44 | 5.23 | 11.9 | 6,540 |
| E-2 | − | − | 0.41 | 9.88 | 23.9 | 8,540 |
| E-3 | ++ | +++ | 0.35 | 8.63 | 24.3 | 6,920 |
| E-4 | − | − | 0.46 | 9.55 | 21.0 | 15,600 |
| E-5 | − | NM | 0.44 | 0.50 | 1.1 | 830 |
| E-6 | − | − | 0.48 | 1.70 | 3.5 | 2,160 |
| E-7 | ± | +++ | 0.46 | 5.63 | 12.2 | 5,930 |
| E-8 | − | NM | 0.47 | 0.38 | 0.8 | 770 |
| E-9 | − | NM | 0.34 | 0.52 | 1.5 | 1,600 |
| E-10 | ++ | +++ | 0.31 | 6.55 | 21.2 | 5,610 |
| E-m | − | ± | 0.52 | 6.86 | 13.1 | 6,670 |
Relative levels of β-globin mRNA (−, ±, +, ++, and +++) in clones before and after exposure to Epo were determined by the intensity of the Northern blots shown in Figs 1 and 3. The β-globin mRNA content in clones E-5, E-8, and E-9 after Epo exposure was not measurable due to the absence of cell growth. Epo-induced cell growth was expressed as the fold increase in the cell density from day 0 (d 0) to day 2 (d 2) in the presence of Epo. Epo binding was measured as described in the Materials and Methods. The values for Friend erythroleukemia and Ba/F3 cells were 7,660 and 440 cpm/3 × 106 cells, respectively.
Abbreviation: NM, not measurable.