Modulation of transcriptional activity of the chicken ovalbumin gene promoter in primary cultures of chicken oviduct cells: effects of putative regulatory elements in the 5'-flanking region.

With primary cultures of chicken oviduct cells, we tested functional roles in the ovalbumin gene transcription of NF-1 like factor binding element, half estrogen-response-element direct repeat, and chicken ovalbumin upstream promoter residing in the 5'-flanking region of the chicken ovalbumin gene. The three putative regulatory elements were fused upstream to the chloramphencol acetyltransferase reporter gene driven by the chicken ovalbumin gene promoters, and transient gene expression was measured in primary cultured oviduct cells. The results indicated that neither the NF1 binding element nor the ovalbumin upstream promoter showed any enhancer-like activity. In addition, although the half estrogen response element direct repeat enhanced transcriptional activity of the ovalbumin gene promoter, it completely deprived the ovalbumin promoter of estrogen dependency. We concluded, therefore, that the biological significance of these three putative regulatory elements in the homologous chicken oviduct cell system might be different from those previously reported in heterologous systems.