INTERGENIC TRANSCRIPTION AND TRANSINDUCTION OF THE HUMAN BETA-GLOBIN LOCUS

We have identified novel nuclear transcripts in the human beta-globin locus using nuclear run-on analysis in erythroid cell lines and in sit u hybridization analysis of erythroid tissue. These transcripts extend across the LCR and intergenic regions but are undetectable in noneryt hroid cells. Surprisingly, transient transfection of a beta-globin gen e (epsilon, gamma, or beta) induces transcription of the LCR and inter genic regions from the chromosomal beta-globin locus in nonerythroid c ell lines. The beta-globin genes themselves, however, remain transcrip tionally silent. Induction is dependent on transcription of the globin gene in the transfected plasmid but does not require protein expressi on. Using in situ hybridization analysis, we show that the plasmid col ocalizes with the endogenous beta-globin locus providing insight into the mechanism of transinduction.