IN SITU LOCALIZATION OF GLOBIN MESSENGER RNA FORMATION : II. After Treatment of Friend Virus-Transformed Mouse Cells with Dimethyl Sulfoxide

Globin messenger RNA (mRNA) levels in Friend virus-transformed mouse cells have been estimated by in situ hybridization of DNA copy (cDNA) to fixed preparations of cells and by hybridization of cDNA to extracted cytoplasmic RNA in true solution. The results obtained by both methods agree in showing that a low level of globin mRNA can be detected in untreated Friend cells. The levels of hemoglobin and globin mRNA have also been correlated after treatment of Friend cells with dimethyl sulfoxide (DMSO). The results obtained by both experimental approaches show that there is a minimum period of treatment with DMSO required in order that Friend cells may become hemoglobinized, and that this period coincides with the time when globin mRNA accumulates. Moreover, bromodeoxyuridine prevents both hemoglobin and globin mRNA accumulation.