Structure of the bovine endothelin-B receptor gene and its tissue-specific expression revealed by northern analysis

We have isolated and characterized the gene encoding the bovine endothelin (ET) receptor ETB with seven putative membrane-spanning domains. The gene exists as a single copy of the bovine genome and extends over 36 kilobases. The coding region is divided into seven exons separated by six introns; the first exon encodes the first and second transmembrane domains and each of the following transmembrane domains is encoded by a separate exon. The 5' region of the transcript was examined by the ribonuclease protection analysis; multiple start sites were deduced with no apparent "TATA" box in the expected upstream region. Northern blot analysis demonstrated a widespread but tissue-specific distribution of the ETB receptor in bovine tissues.