Cloning and Comparison of Prolactin Promoter in Galliformes

Abstract

To investigate the mechanism regulating transcription of the prolactin (PRL) gene in avian species, the PRL promoter region in Ceylon junglefowl, Japanese quail, ring-necked pheasant, turkey, Indian peafowl and helmeted guineafowl were cloned and sequenced. In each species, approximately 4,800-5,900bp were sequenced. The PRL promoters of 7 galliformes including red junglefowl were found to have, on average, 91.2% sequence identity over the entire region and 97% sequence identity was observed in the proximal promoter (from the initiation codon (+55) to -130). Moreover, average of sequence identities was 91.6% among 11 avian species (7 galliformes, duck, Java sparrow, budgerigar and ostrich). In the PRL proximal promoter, putative Pit-1 binding site and vasoactive intestinal peptide response element were conserved among avian species. These results suggest that that the mechanisms involved in gene expression of PRL may be conserved in Galliformes.