title: The rod and green cone opsins of two avian species, the budgerigar, Melopsittacus undulatus, and the mallard duck, Anas platyrhynchus.
abstract: The genes for the rod and rod-like green cone opsins in two avian species, the budgerigar, Melopsittacus undulatus, and the mallard duck, Anas platyrhynchus, are identified on the basis of amino acid identity with the equivalent chicken sequences and their placement into a single phylogenetic clade with the rod and rod-like green cone opsin genes from other vertebrate species. Since the two bird species studied are taxonomically quite distinct, this would indicate that this rod-like green cone opsin gene, although absent in mammals, is common in the Aves. The two avian pigments differ consistently at site 122, consistent with the reported role of this site in determining the rate of metarhodopsin II formation and decay in rod and cone pigments. Candidate sites are identified to compensate for the known spectral effects of substitution at this site.
authors.affiliation: Department of Molecular Genetics, Institute of Ophthalmology, University College London, UK.
authors.forename: L A
authors.initials: LA
authors.lastname: Heath
authors.forename: S E
authors.initials: SE
authors.lastname: Wilkie
authors.forename: J K
authors.initials: JK
authors.lastname: Bowmaker
authors.forename: D M
authors.initials: DM
authors.lastname: Hunt
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D018076:DNA, Complementary; D004372:Ducks / Q000235:genetics*; D006801:Humans; D015591:Microspectrophotometry / Q000379:methods; D008969:Molecular Sequence Data; D010311:Parrots / Q000235:genetics*; D017949:Retinal Cone Photoreceptor Cells / Q000737:chemistry*; D017948:Retinal Rod Photoreceptor Cells / Q000737:chemistry*; D017299:Rod Opsins / Q000235:genetics*; D017386:Sequence Homology, Amino Acid
chemical_list: D018076:DNA, Complementary; D017299:Rod Opsins; C095854:middle-wavelength opsin