title: Three neuropeptide Y receptor genes in the spiny dogfish, Squalus acanthias, support en bloc duplications in early vertebrate evolution.
abstract: It has been debated whether the increase in gene number during early vertebrate evolution was due to multiple independent gene duplications or synchronous duplications of many genes. We describe here the cloning of three neuropeptide Y (NPY) receptor genes belonging to the Y1 subfamily in the spiny dogfish, Squalus acanthias, a cartilaginous fish. The three genes are orthologs of the mammalian subtypes Y1, Y4, and Y6, which are located in paralogous gene regions on different chromosomes in mammals. Thus, these genes arose by duplications of a chromosome region before the radiation of gnathostomes (jawed vertebrates). Estimates of duplication times from linearized trees together with evidence from other gene families supports two rounds of chromosome duplications or tetraploidizations early in vertebrate evolution. The anatomical distribution of mRNA was determined by reverse-transcriptase PCR and was found to differ from mammals, suggesting differential functional diversification of the new gene copies during the radiation of the vertebrate classes.
authors.affiliation: Department of Neuroscience, Unit of Pharmacology, Evolutionary Biology Center, Uppsala University, Uppsala, Sweden.
authors.forename: Erik
authors.initials: E
authors.lastname: Salaneck
authors.forename: David H
authors.initials: DH
authors.lastname: Ardell
authors.forename: Earl T
authors.initials: ET
authors.lastname: Larson
authors.forename: Dan
authors.initials: D
authors.lastname: Larhammar
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D004284:Dogfish / Q000145:classification / Q000235:genetics*; D019143:Evolution, Molecular; D005260:Female; D020440:Gene Duplication; D016013:Likelihood Functions; D008969:Molecular Sequence Data; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D017476:Receptors, Neuropeptide Y / Q000737:chemistry / Q000145:classification / Q000235:genetics*; D016415:Sequence Alignment
chemical_list: D017476:Receptors, Neuropeptide Y; C097212:neuropeptide Y-Y1 receptor