title: Distribution of rod- and cone-specific phosducins in retinas of non-mammalian vertebrates.
abstract: In mammalian retinas, it has been believed that just one kind of phosducin (PD) commonly exists in both rods and cones. However, we have previously reported that there are rod- and cone-specific PDs (OlPD-R and OlPD-C) in medaka (Oryzias latipes) retina [FEBS Lett., 502, 117-121, 2001]. To clarify the distribution and evolution of these photoreceptor type-specific PDs, we investigated PDs of another teleost and a reptile. Immunohistochemical and Western blot analyses using anti-medaka PD antisera demonstrated that two kinds of PDs are expressed in zebrafish (Danio rerio) photoreceptor cells. Our study is suggestive that teleosts generally possess rod- and cone-specific PDs. We isolated a cDNA encoding putative PD (PmlPD) of a diurnal gecko (Phelsuma madagascariensis longinsulae). Because diurnal gecko possesses a pure-cone retina, it was expected that PmlPD would be expressed in cones. Molecular phylogenetic analysis demonstrated that PmlPD was more closely related to mammalian PDs than teleost cone-specific PDs, suggesting that the rod- and cone-specific subtype of teleost PDs have arisen after the teleost-tetrapod divergence.
authors.affiliation: Department of Earth and Space Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Osamu
authors.initials: O
authors.lastname: Hisatomi
authors.forename: Shintaro
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Fumio
authors.initials: F
authors.lastname: Tokunaga
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D019143:Evolution, Molecular; D005136:Eye Proteins / Q000032:analysis* / Q000235:genetics; D005399:Fishes; D020555:GTP-Binding Protein Regulators; D007150:Immunohistochemistry; D008969:Molecular Sequence Data; D009928:Organ Specificity; D010750:Phosphoproteins / Q000032:analysis* / Q000235:genetics; D010802:Phylogeny; D017949:Retinal Cone Photoreceptor Cells / Q000737:chemistry*; D017948:Retinal Rod Photoreceptor Cells / Q000737:chemistry*; D016415:Sequence Alignment; D029961:Zebrafish Proteins / Q000032:analysis*
chemical_list: D005136:Eye Proteins; D020555:GTP-Binding Protein Regulators; D010750:Phosphoproteins; D029961:Zebrafish Proteins; C065631:phosducin