RT-PCR analysis in mGATA-1–infected MGS cells. Changes in the expression of erythroid and megakaryocytic genes in MGS cells under forced expression of GATA-1. MGS cells were infected with MSCV–mGATA-1 retrovirus containing full-length mGATA-1 or MSCV vector alone. The cells were then cultured either in the presence of Epo (+EPO, 2 units/mL) or without the cytokine (–EPO). The expression levels of mouse GATA-1 (mGATA-1), human GATA-2 (hGATA-2), EpoR, α-globin, γ-globin, ALAS-E, PF4, and c-mpl were analyzed by RT-PCR. The G3PDH expression level was measured exploiting the National Institutes of Health (NIH) image software (Rockville, MD) and the RT-PCR condition was standardized with the data. In each case, the numeric value without (w/o) infection and without (w/o) EPO was set as 1. The number of PCR cycles is shown in the right side of each panel.