Selective activation of human β - but not γ-globin gene in human fibroblast × mouse erythroleukaemia cell hybrids

Abstract
The human .alpha.- and .beta.-globin genes were activated in MEL [mouse erythroleukemia] .times. human fibroblast cell hybrids. Even though the human .gamma.- and .beta.-globin genes are closely linked and were present in approximately equal numbers, no human .gamma.-globin mRNA was produced. The human .beta.- and .gamma.-globin genes in these cells apparently are differentially regulated by a positive regulatory factor(s) specific for individual globin genes.