title: Cloning, molecular characterization, and distribution of a gene homologous to delta opioid receptor from zebrafish (Danio rerio).
abstract: A full-length cDNA, ZFOR1, has been isolated from the teleost zebrafish (Danio rerio) using a probe from rat mu opioid receptor. ZFOR1 encodes a 373 amino acid protein with seven potential transmembrane domains that shows a high degree of homology to mammalian delta opioid receptor. We have also isolated a genomic clone which contains two exons of ZFOR1, homologous to exons 2 and 3 in mouse and human delta opioid receptor. Expression of ZFOR1 appears to be restricted to nervous tissue as assessed by Northern blot. In situ hybridization in zebrafish brain with specific probes revealed several discrete areas of ZFOR1 expression; higher levels are detected in dorsal telencephalic areas, the periventricular layer of the optic tectum, and the granular layer of the cerebellum. This is the first molecular evidence of the presence of the delta opioid receptor in a non-mammalian species and suggests that it has been highly conserved throughout vertebrate evolution.
authors.affiliation: Department of Biochemistry and Molecular Biology, Faculty of Medicine, University of Salamanca, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Barrallo
authors.forename: R
authors.initials: R
authors.lastname: González-Sarmiento
authors.forename: A
authors.initials: A
authors.lastname: Porteros
authors.forename: M
authors.initials: M
authors.lastname: García-Isidoro
authors.forename: R E
authors.initials: RE
authors.lastname: Rodríguez
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000378:metabolism; D003001:Cloning, Molecular; D017124:Conserved Sequence / Q000235:genetics; D019143:Evolution, Molecular; D005091:Exons / Q000235:genetics; D017403:In Situ Hybridization; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000032:analysis; D017465:Receptors, Opioid, delta / Q000737:chemistry*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid; D015027:Zebrafish
chemical_list: D012333:RNA, Messenger; D017465:Receptors, Opioid, delta