title: Interphotoreceptor matrix in the human retina: cone-like domains surround a small population of rod photoreceptors.
abstract: The interphotoreceptor matrix (IPM) in mammalian retinas is subdivided into rod and cone specific compartments: peanut agglutinin (PNA) binding glycoconjugates are associated with cones, whereas wheat germ agglutinin (WGA) binding glycoconjugates are associated with rods. To establish the identity of a photoreceptor cell type in the human retina with rod dimensions but with a matrix domain which stains with PNA, double label studies, using PNA-ferritin to decorate the extracellular domains and immunocytochemical techniques using a rod specific anti-opsin antibody were conducted. The PNA-binding domains were observed in the cone-associated IPM as well as in the IPM surrounding a small population of rod-shaped photoreceptors. The outer segments of these rod-shaped photoreceptors showed intense labeling with a rod specific anti-opsin antibody as did all other rods which were free of PNA-labeling. A quantitative analysis of all retinal quadrants indicates that this novel rod represents approximately 0.3% of the total rod population in the human retina.
authors.affiliation: Cullen Eye Institute, Baylor College of Medicine, Houston, Texas 77030.
authors.forename: M
authors.initials: M
authors.lastname: Iwasaki
authors.forename: K M
authors.initials: KM
authors.lastname: Myers
authors.forename: M E
authors.initials: ME
authors.lastname: Rayborn
authors.forename: J G
authors.initials: JG
authors.lastname: Hollyfield
mesh_terms: D010367:Arachis; D005136:Eye Proteins / Q000032:analysis; D006001:Glycoconjugates / Q000032:analysis; D006801:Humans; D007150:Immunohistochemistry; D037102:Lectins; D008856:Microscopy, Fluorescence; D016253:Microscopy, Immunoelectron; D008875:Middle Aged; D019887:Peanut Agglutinin; D010786:Photoreceptor Cells / Q000648:ultrastructure*; D037121:Plant Lectins; D012160:Retina / Q000166:cytology* / Q000648:ultrastructure; D017299:Rod Opsins; D014909:Wheat Germ Agglutinins
chemical_list: D005136:Eye Proteins; D006001:Glycoconjugates; D037102:Lectins; D019887:Peanut Agglutinin; D037121:Plant Lectins; D017299:Rod Opsins; D014909:Wheat Germ Agglutinins