An erythroid-specific, developmental-stage-independent enhancer far upstream of the human 'β-like globin' genes

We have identified an erythroid-specific enhancer element far upstream of the human 'β-like globin' genes, at 10.2-11.0 kilobases 5' of the embryonic ε-globin gene, and thus at 53-54 kilobases 5' of the adult β-globin gene. It is capable of enhancing the expression of a cis-linked test gene by up to 300-fold. This enhancer element is apparently developmental-stage-independent, as it is functional at the embryonic and the adult developmental stages in erythroid cells that are expressing the respective β-like globin genes. The enhancer and globin promoter sequences work in synergy and are capable of conferring on a cis-linked gene the high transcriptional efficiency (enhancer function), erythroid specificity (enhancer and promoter functions), and developmental-stage specificity (promoter function) that are characteristic of the in vivo transcription of the β-like globin genes in erythroid cells.