Structure of mouse vasopressin and oxytocin genes.
Mouse vasopressin (VP) and oxytocin (OT) genes were isolated from a genomic library and the nucleotide sequences of the two genes were determined. The two genes have similar three exon structures and a high similarity in the part of exon 1 encoding vasopressin or oxytocin nonapeptide and in exon 2 encoding the central core of neurophysin. They are linked together in a tail to tail orientation separated by a short 3.5 kb intergenic sequence and are transcribed from opposite strands. Both genes have a single transcription initiation site downstream from a TATA-like sequence and a single polyadenylated transcript of about 760 bp for the vasopressin mRNA and about 700 bp for the oxytocin mRNA.