Coactivation of human alpha1- and alpha2-globin genes in single induced MEL cells containing one human alpha-globin...

We developed a reverse-transcription polymerase chain reaction assay, performed on single isolated cells, to demonstrate the coexpression of human alpha1- and alpha2-globin mRNA in induced mouse erythroleukemic cells containing a single human alpha-globin locus. These results indicate that both alpha1 and alpha2 genes are activated from the same alpha-globin gene locus implying that HS-40-dependent transcriptional activation is mediated, either by a simultaneous interaction of HS-40 with both a alpha1 and alpha2-globin gene promoters, or by a dynamic process characterized by alternative, but short-lived, interactions with each alpha-globin gene promoter.