Hemoglobin synthesis in somatic cell hybrids: globin gene expression in hybrids between mouse erythroleukemia and...

Somatic cell hybrids were generated by fusion of mouse erythroleukemia cells either to mouse L cells (B82), human fibroblasts (W1-18 VA2), or human marrow fractions enriched in erythroblasts. The hybrid cells were examined for globin gene expression by benzidine staining to detect cytoplasmic hemoglobin, and by molecular hybridization of cellular RNA to globin complementary DNA (cDNA) to detect globin messenger RNA (MRNA). The fibroblast (human or mouse) times erythroleukemia cell hybrids grown in monolayer retained most of the chromosomes of each parent. Neither cytoplasmic hemoglobin nor globin mRNA was detected in dimethylsulfoxide-treated fibroblast times erythroleukemia hybrid cells, indicating extinction of hemoglobin synthesis prior to the formation of cytoplasmic mRNA. The human marrow times mouse erythroleukemia hybrid cells grown in suspension culture contained only a few human chromosomes and exhibited low levels of hemoglobin synthesis which were amplified by 2% dimethylsulfoxide. Mouse (but not human) globin mRNA was demonstrated in these hybrid cells. The results suggest that somatic cell hybrids may be useful in searching for genetic factors which regulate activity of the globin genes.