Genomic characterization of the sheep vasopressin V1a receptor gene and promoter, with assignment to bands q23-24 of sheep chromosome 3 and cattle chromosome 5

Arginine vasopressin interacts with the vasopressin type 1a receptor (V1aR) to initiate physiological effects such as vasoconstriction of blood vessel s and glycogenolysis, AVP is also involved in central nervous effects such as body homeostasis and blood pressure control. The complete genomic organi zation of the sheep V1aR gene has been determined, including the presence o f one major and two minor transcriptional start sites at -321, -206 and -91 bp respectively, relative to the ATC codon. Another more distal minor trans criptional start site was also localized between nucleotides -997 and -892 relative to the ATG codon. One intron exists in the sheep V1aR gene and pot ential cis- and trans- acting sites were identified in the sheep V1aR promo ter. The promoter was also compared to the rat V1aR promoter. The sheep V1a R promoter displays features typical of housekeeping genes, although tissue -specific expression does not support this. V1aR mRNA is absent in the adul t sheep liver but not the kidney. One copy of the V1aR gene exists in the s heep genome, which was localized to chromosome 3q23-24, and to the homoeolo gous position, 5q23-24 in cattle. (C) 1999 Elsevier Science B.V. All rights reserved.