Accumulation of α- and β-globin messenger RNAs in mouse erythroleukemia cells

The accumulation of α- and β-globin mRNA sequences in murine erythroleukemia cells (MELC) treated with various inducers has been studied using specific α- and β-globin complementary DNAs (cDNAs). In cells cultured with dimethylsulfoxide (Me₂SO), hexamethylene bisacetamide (HMBA) or butyric acid, accumulation of α-globin mRNA is detectable after 16, 12 and 8 hr of culture, respectively. An increase in β-globin mRNA sequences is not detected until 20–24 hr after culture. In cells exposed to hemin, both α- and β-globin mRNAs are detectable by 6 hr of culture, and a constant ratio of $\text{α}\text{β}\text{-}\text{mRNA}$ is maintained during induction. In maximally induced cells, the $\text{α}\text{β}\text{-}\text{globin}$ 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 α- and β-like genes. In addition, the relative accumulation of α- and β-globin mRNAs in induced cells differs with various types of inducers.