Trans-acting factors that interact with the proximal promoter sequences of ovalbumin gene are tissue-specific and age-related.

Aging or deterioration of functions of various organs occurs after adulthood due to alterations in the expression of genes that maintain adulthood functions. Molecular changes that occur in regulation of genes in higher organisms after adulthood can be understood by using genes whose timing and rate of expression run parallel with specific functions during the life span. One such function is egg formation in birds which is dependent on the expression of egg protein genes, ovalbumin, lysozyme, vitellogenin, etc. Trans-acting factors are known to play a pivotal role in the regulation of transcription of genes. We show here a decrease in the level/binding of nuclear trans-acting factors with specific cis-acting elements of the promoter of the ovalbumin gene of oviduct of old Japanese quail. This parallels the decrease in the expression of the ovalbumin gene in the oviduct after adulthood. These factors are tissue-specific and bind in a cooperative and sequential manner to the ovalbumin gene promoter.