Differential expression of human globin genes introduced in K562 cells

We have constructed a series of hybrid globin genes between the 5' half of the human epsilon-, gamma- and beta-globin genes, and the 3' half of the rabbit beta-globin gene. These hybrid genes were introduced into the cell line K562. Analysis of the hybrid mRNA populations show that only the hybrid epsilon- and gamma-globin genes are expressed in these cells in concordance with the endogenous K562 globin gene expression. It is therefore likely that these cells contain transcriptional factors which allow the specific expression of introduced epsilon- and gamma-, but not beta-globin genes, irrespective of their chromosomal localization.