Definition of the ovalbumin gene promoter by transfer of an ovalglobin fusion gene into cultured cells.

In order to study the initiation of transcription from the ovalbumin gene promoter, we constructed a hybrid gene (ovalglobin) in which 753 bps of ovalbumin gene 5'-flanking sequence were joined to the chicken adult beta-globin gene. When transfected into HeLa S3 cells, ovalglobin gene transcription initiated at the ovalbumin gene cap site, as measured by S1 nuclease and primer extension analysis. Deletion of 5'-flanking sequences to position -95 had little effect on transcription; deletion to -77 reduced transcription to about 20% of the wild type level and deletion to -48 reduced the level to about 2%. A deletion to -24, removing the sequence TATATAT, abolished transcription entirely. Hormonal regulation of the ovalglobin gene was observed when primary oviduct cells were used as recipients for DNA transfection. Under these conditions, addition of progesterone increased the level of ovalglobin transcripts to more than 10 times the uninduced level.