PUBLICATION
Retrograde Intraflagellar Transport by Cytoplasmic Dynein-2 is Required for Outer Segment Extension in Vertebrate Photoreceptors but not Arrestin Translocation
- Authors
- Krock, B.L., Mills-Henry, I., and Perkins, B.
- ID
- ZDB-PUB-090601-13
- Date
- 2009
- Source
- Investigative ophthalmology & visual science 50(11): 5463-5471 (Journal)
- Registered Authors
- Perkins, Brian
- Keywords
- photoreceptor renewal, retinal development, outer segments, dark adaptation
- MeSH Terms
-
- Animals
- Arrestin/metabolism*
- Blotting, Western
- Brain/embryology
- Cytoplasmic Dyneins/physiology*
- Electrophoresis, Polyacrylamide Gel
- Electroretinography
- Embryo, Nonmammalian/metabolism
- Fluorescent Antibody Technique, Indirect
- In Situ Hybridization
- Kidney/embryology
- Photoreceptor Cells, Vertebrate
- Protein Transport
- Retinal Photoreceptor Cell Outer Segment
- Reverse Transcriptase Polymerase Chain Reaction
- Zebrafish
- Zebrafish Proteins/physiology*
- PubMed
- 19474410 Full text @ Invest. Ophthalmol. Vis. Sci.
Citation
Krock, B.L., Mills-Henry, I., and Perkins, B. (2009) Retrograde Intraflagellar Transport by Cytoplasmic Dynein-2 is Required for Outer Segment Extension in Vertebrate Photoreceptors but not Arrestin Translocation. Investigative ophthalmology & visual science. 50(11):5463-5471.
Abstract
PURPOSE. Anterograde Intraflagellar Transport (IFT) is essential for photoreceptor outer segment formation and maintenance, as well as for opsin trafficking. However, the role of retrograde IFT in vertebrate photoreceptors remains unclear. The purpose of this study was to evaluate zebrafish photoreceptors lacking the retrograde IFT motor, cytoplasmic dynein-2. METHODS. Morpholino oligonucleotides against the heavy chain (dync2-h1), light intermediate chain (dync2-li1) and intermediate chain (dync2-i1) subunits of cytoplasmic dynein-2 were injected into zebrafish embryos. Retinas and ciliated cells of these zebrafish 'morphants' were analyzed by immunohistochemistry and transmission electron microscopy. Whole field electroretinograms (ERGs) were performed on dynein morphants at 5-6 days post fertilization (dpf). RESULTS. Zebrafish lacking cytoplasmic dynein-2 function exhibited small eyes, kidney cysts, and short photoreceptor outer segments, some of which were disorganized and accumulated vesicles. Morphant photoreceptor connecting cilia were swollen, but neither opsin nor arrestin was mislocalized, while IFT88 accumulated in the distal region of the connecting cilium. Nasal cilia were shortened and displayed cytoplasmic swelling along the axoneme. Loss of cytoplasmic dynein-2 function resulted in a significant reduction in the amplitude of ERG a-, b-, and d-waves but no change in threshold response. CONCLUSIONS. Our study shows that retrograde IFT is essential for outer segment extension and IFT protein recycling in vertebrate photoreceptors. We show for the first time that the dync2-i1 subunit of cytoplasmic dynein-2 is necessary for retrograde IFT. Additionally, arrestin translocation does not require retrograde IFT. Finally, our ERG results indicate that loss of cytoplasmic dynein-2 reduces the photoreceptor light response.
Genes / Markers
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Orthology
Engineered Foreign Genes
Mapping