title: The intraflagellar transport protein ift80 is essential for photoreceptor survival in a zebrafish model of jeune asphyxiating thoracic dystrophy.
abstract: PURPOSE. Jeune's asphyxiating thoracic dystrophy (JATD) is an autosomal recessive disorder with symptoms of retinal degeneration, kidney cysts, and chondrodysplasia and results from mutations in the ift80 gene. This study was conducted to characterize zebrafish lacking ift80 function for photoreceptor degeneration and defects in ciliogenesis to establish zebrafish as a vertebrate model for visual dysfunction in JATD and to determine whether ift80 interacts genetically with Bardet-Biedl syndrome (BBS) genes. METHODS. Zebrafish were injected with morpholinos (MOs) targeted to the ift80 gene. Retinas were analyzed by histology, transmission electron microscopy, and immunohistochemistry. Ear and kidney cilia were analyzed by whole-mount immunostaining. Intraflagellar transport (IFT) particle composition was subjected to Western blot analysis. Genetic interactions were tested by coinjection of MOs against ift80 and bbs4 or bbs8 followed by in situ hybridization. RESULTS. Zebrafish lacking ift80 function exhibited defects in photoreceptor outer segment formation and photoreceptor death. Staining with opsin antibodies revealed opsin mislocalization in both rods and cones. Ultrastructural analysis showed abnormal disc stacking and shortened photoreceptor outer segments. The kinocilia of the ear and motile cilia in the kidney were shorter and reduced in number. Western blot analysis revealed a slight increase in the stability of other IFT proteins. Coinjection of MOs against ift80 and BBS genes led to convergent-extension defects. CONCLUSIONS. Zebrafish lacking ift80 exhibited defects characteristic of JATD. Because the developing outer segments degenerated, Ift80 could possibly act as a maintenance factor for the IFT particle.
authors.affiliation: Department of Biology, Texas A&M University, College Station, Texas, USA.
authors.forename: Leah M
authors.initials: LM
authors.lastname: Hudak
authors.forename: Shannon
authors.initials: S
authors.lastname: Lunt
authors.forename: Chi-Hsuan
authors.initials: CH
authors.lastname: Chang
authors.forename: Ethan
authors.initials: E
authors.lastname: Winkler
authors.forename: Halley
authors.initials: H
authors.lastname: Flammer
authors.forename: Michael
authors.initials: M
authors.lastname: Lindsey
authors.forename: Brian D
authors.initials: BD
authors.lastname: Perkins
mesh_terms: D000818:Animals; D001237:Asphyxia / Q000235:genetics / Q000473:pathology*; D015153:Blotting, Western; D002352:Carrier Proteins / Q000502:physiology*; D002470:Cell Survival / Q000502:physiology; D004195:Disease Models, Animal; D004591:Electrophoresis, Polyacrylamide Gel; D005097:Exostoses, Multiple Hereditary / Q000235:genetics / Q000473:pathology*; D019084:Fluorescent Antibody Technique, Indirect; D020868:Gene Silencing / Q000187:drug effects; D017403:In Situ Hybridization; D020287:In Situ Nick-End Labeling; D052177:Kidney Diseases, Cystic / Q000235:genetics / Q000473:pathology; D020419:Photoreceptor Cells, Vertebrate / Q000473:pathology*; D012162:Retinal Degeneration / Q000235:genetics / Q000473:pathology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013896:Thoracic Diseases / Q000235:genetics / Q000473:pathology*; D015027:Zebrafish; D029961:Zebrafish Proteins / Q000502:physiology*
chemical_list: D002352:Carrier Proteins; C551175:IFT80 protein, zebrafish; D029961:Zebrafish Proteins