Accumulation of alpha- and beta-globin messenger RNAs in mouse erythroleukemia cells.

The accumulation of alpha- and beta-globin mRNA sequences in murine erythroleukemia cells (MELC) treated with various inducers has been studied using specific alpha- and beta-globin complementary DNAs (cDNAs). In cells cultured with dimethylsulfoxide (Me2SO), hexamethylene bisacetamide (HMBA) or butyric acid, accumulation of alpha-globin mRNA is detectable after 16, 12 and 8 hr of culture, respectively. An increase in beta-globin mRNA sequences is not detected until 20-24 hr after culture. In cells exposed to hemin, both alpha- and beta-globin mRNAs are detectable by 6 hr of culture, and a constant ratio of alpha/beta-mRNA is maintained during induction. In maximally induced cells, the alpha/beta-globin mRNA ratios are approximately 1 in cells induced by Me2SO and HMBA, and 0.66 and 0.3-0.50 in cells induced by butyric acid and hemin, respectively. Thus different inducers of erythroid differentiation in MELC lead to different times of onset of the expression of alpha- and beta-like genes. In addition, the relative accumulation of alpha- and beta-globulin mRNAs in induced cells differs with various types of inducers.