Quantitation of globin mRNA in individual human erythroblasts by in situ hybridization.

In situ hybridization of globin mRNA was performed in four human bone marrows using a 3H-cDNA derived from rat globin messenger. Erythroblasts were classified according to nuclear area as well as to morphological appearance after Giemsa staining. Grains over individual erythroblasts and reticulocytes were counted by incident light microphotometry. Reticulocytes from phenyl hydrazine-treated rats served as internal standards in order to allow a comparison of different experiments. The preliminary results from one normal bone marrow, one of stress erythropoiesis and two of aplastic anemia revealed the major content of globin mRNA in the states of basophilic erythroblasts or proerythroblasts. In all cases there was a tendency of decreasing globin mRNA content towards orthochromatic erythroblasts, and even more so, towards reticulocytes. The results show some differences between normal and diseased erythropoiesis which are under study on a larger scale now in order to ascertain their significance.