title: Two ribeye genes in teleosts: the role of Ribeye in ribbon formation and bipolar cell development.
abstract: Ribeye is the only known protein specific to synaptic ribbon, but its function is unclear. We show that the teleost fish, Fugu and zebrafish, have two ribeye genes, ribeye a and ribeye b. Whole-mount in situ hybridization revealed that ribeye a is expressed in tissues containing synaptic ribbons, including the pineal gland, inner ear, and retina. Ribeye b is absent in the pineal gland. In the retina, ribeye a is expressed in both photoreceptors and bipolar cells, whereas ribeye b is detected only in photoreceptors. To study the function of Ribeye a in retina, we depleted it by morpholino antisense oligos. Fish deficient in Ribeye a lack an optokinetic response and have shorter synaptic ribbons in photoreceptors and fewer synaptic ribbons in bipolar cells. Their bipolar cells still target Syntaxin-3 proteins to the inner plexiform layer and have abundant vsx1 mRNA. However, they lack large synaptic terminals and show increased apoptosis. Rod bipolar cells are fewer in number and/or deficient in PKCalpha. Recovery of Ribeye a levels rescues the optokinetic response, increases the number of PKCalpha-positive bipolar cells, and stops apoptosis. We conclude that Ribeye a is important for late steps in bipolar cell development.
authors.affiliation: Vollum Institute, Oregon Health and Science University, Portland, Oregon 97239, USA.
authors.forename: Lei
authors.initials: L
authors.lastname: Wan
authors.forename: Wolfhard
authors.initials: W
authors.lastname: Almers
authors.forename: Wenbiao
authors.initials: W
authors.lastname: Chen
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology; D005136:Eye Proteins / Q000235:genetics / Q000502:physiology*; D018507:Gene Expression Regulation, Developmental; D007395:Interneurons / Q000502:physiology; D007814:Larva / Q000254:growth & development; D020319:Oligodeoxyribonucleotides, Antisense; D010775:Photic Stimulation; D017729:Presynaptic Terminals / Q000648:ultrastructure; D012160:Retina / Q000033:anatomy & histology* / Q000254:growth & development / Q000502:physiology; D023741:Takifugu / Q000033:anatomy & histology* / Q000196:embryology / Q000235:genetics / Q000254:growth & development; D015027:Zebrafish / Q000033:anatomy & histology* / Q000196:embryology / Q000235:genetics / Q000254:growth & development
chemical_list: D005136:Eye Proteins; D020319:Oligodeoxyribonucleotides, Antisense