title: Functionally rodless mice: transgenic models for the investigation of cone function in retinal disease and therapy.
abstract: Two genetically engineered strains of mice were used to characterize murine cone function electroretinographically, without interference of rod-driven responses: (1) mice with a deletion of the gene for the rod transducin alpha-subunit (transducin alpha-/-), and (2) mice with rod arrestin deleted (arrestin -/-). In the first three months of age, both strains have a normal complement of rods and normal rod structure, but transducin alpha-/- mice have no rod-driven responses to light, while rod-driven activity of arrestin -/- mice can be suppressed by a single intense flash for hours. In response to intense flashes the electroretinograms of these strains of mice showed a readily identifiable, pure-cone a-wave of approximately 10 microV saturating amplitude. A 530 nm background that saturates rod responses of wild type mice was found to desensitize the b-wave responses of mice of both transgenic lines, whether the b-waves were driven by photons captured by M- or UV-cone pigments. The desensitizing effect of the 530 nm background on UV-pigment driven responses provides new evidence in support of the hypothesis of functional co-expression of the M-pigment in cones expressing primarily the UV-pigment.
authors.affiliation: Department of Ophthalmology, F.M. Kirby Center for Molecular Ophthalmology, Stellar-Chance Building, Room 309B, School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6069, USA.
authors.forename: A L
authors.initials: AL
authors.lastname: Lyubarsky
authors.forename: J
authors.initials: J
authors.lastname: Lem
authors.forename: J
authors.initials: J
authors.lastname: Chen
authors.forename: B
authors.initials: B
authors.lastname: Falsini
authors.forename: A
authors.initials: A
authors.lastname: Iannaccone
authors.forename: E N
authors.initials: EN
authors.lastname: Pugh
mesh_terms: D000818:Animals; D019393:Arrestin / Q000235:genetics*; D004596:Electroretinography; D051379:Mice; D008822:Mice, Transgenic; D023421:Models, Animal; D010775:Photic Stimulation; D017949:Retinal Cone Photoreceptor Cells / Q000503:physiopathology*; D012164:Retinal Diseases / Q000503:physiopathology* / Q000628:therapy; D017948:Retinal Rod Photoreceptor Cells; D015293:Transducin / Q000235:genetics*
chemical_list: D019393:Arrestin; D015293:Transducin