title: A visual pigment expressed in both rod and cone photoreceptors.
abstract: Rods and cones contain closely related but distinct G protein-coupled receptors, opsins, which have diverged to meet the differing requirements of night and day vision. Here, we provide evidence for an exception to that rule. Results from immunohistochemistry, spectrophotometry, and single-cell RT-PCR demonstrate that, in the tiger salamander, the green rods and blue-sensitive cones contain the same opsin. In contrast, the two cells express distinct G protein transducin alpha subunits: rod alpha transducin in green rods and cone alpha transducin in blue-sensitive cones. The different transducins do not appear to markedly affect photon sensitivity or response kinetics in the green rod and blue-sensitive cone. This suggests that neither the cell topology or the transducin is sufficient to differentiate the rod and the cone response.
authors.affiliation: Department of Ophthalmology, Medical University of South Carolina, Charleston, SC 29425, USA. majx@musc.edu
authors.forename: J
authors.initials: J
authors.lastname: Ma
authors.forename: S
authors.initials: S
authors.lastname: Znoiko
authors.forename: K L
authors.initials: KL
authors.lastname: Othersen
authors.forename: J C
authors.initials: JC
authors.lastname: Ryan
authors.forename: J
authors.initials: J
authors.lastname: Das
authors.forename: T
authors.initials: T
authors.lastname: Isayama
authors.forename: M
authors.initials: M
authors.lastname: Kono
authors.forename: D D
authors.initials: DD
authors.lastname: Oprian
authors.forename: D W
authors.initials: DW
authors.lastname: Corson
authors.forename: M C
authors.initials: MC
authors.lastname: Cornwall
authors.forename: D A
authors.initials: DA
authors.lastname: Cameron
authors.forename: F I
authors.initials: FI
authors.lastname: Harosi
authors.forename: C L
authors.initials: CL
authors.lastname: Makino
authors.forename: R K
authors.initials: RK
authors.lastname: Crouch
mesh_terms: D000557:Ambystoma; D000818:Animals; D017949:Retinal Cone Photoreceptor Cells / Q000378:metabolism*; D012168:Retinal Pigments / Q000096:biosynthesis*; D017948:Retinal Rod Photoreceptor Cells / Q000378:metabolism*; D015293:Transducin / Q000096:biosynthesis
chemical_list: D012168:Retinal Pigments; D015293:Transducin