Movement of retinal along cone and rod photoreceptors

1994 ◽  
Vol 11 (2) ◽  
pp. 389-399 ◽  
Author(s):  
Jing Jin ◽  
Gregor J. Jones ◽  
M. Carter Cornwall
Keyword(s):  
Cell Body ◽  
Dark Adaptation ◽  
Visual Pigment ◽  
Outer Segment ◽  
Light Adaptation ◽  
Rod Photoreceptors ◽  
Rod Outer Segment ◽  
Rods And Cones ◽  
Outer Segments ◽  
Rod Cell

AbstractSingle isolated photoreceptors can be taken through a visual cycle of light adaptation by bleaching visual pigment, followed by dark adaptation when supplied with 11–cis retinal. Light adaptation after bleaching is manifested by faster response kinetics and a permanent reduction in sensitivity to light flashes, presumed to be due to the presence of bleached visual pigment. The recovery of flash sensitivity during dark adaptation is assumed to be due to regeneration of visual pigment to pre-bleach levels. In previous work, the outer segments of bleached, light-adapted cells were exposed to 11–cis retinal. In the present work, the cell bodies of bleached photoreceptors were exposed. We report a marked difference between rods and cones. Bleached cones recover sensitivity when their cell bodies are exposed to 11–cis retinal. Bleached rods do not. These results imply that retinal can move freely along the cone photoreceptor, but retinal either is not taken up by the rod cell body or retinal cannot move from the rod cell body to the rod outer segment. The free transfer of retinal along cone but not along rod photoreceptors could explain why, during dark adaptation in the retina, cones have access to a store of 11–cis retinal which is not available to rods. Additional experiments investigated the movement of retinal along bleached rod outer segments. The results indicate that retinal can move along the rod outer segment, but that this movement is slow, occurring at about the same rate as the regeneration of visual pigment.

scholarly journals Correlation of rhodopsin biogenesis with ultrastructural morphogenesis in the chick retina.

1975 ◽  
Vol 64 (1) ◽  
pp. 235-241 ◽  
Author(s):  
W T Mason ◽  
K J Bighouse
Keyword(s):  
Outer Segment ◽  
Receptor Cell ◽  
Rod Outer Segments ◽  
Membrane Biogenesis ◽  
Rod Outer Segment ◽  
Rods And Cones ◽  
Outer Segments ◽  
Chick Retina ◽  
Disk Membrane ◽  
Detergent Extraction

The developing chick retina from stages 39-45 has been examined by biochemical and electron microscope techniques. The levels of rhodopsin contained in the maturing chick retina were evaluated by detergent extraction and correlated with rod outer segment formation. It was found that the appearance of rhodopsin in significant levels preceded outer segment formation by at least 2 days, thus implying that rhodopsin is synthesized in the receptor cell inner segment and translocated to the outer limb when disk membrane biogenesis occurs. The level of rhodopsin continues to rise as the rod outer segment develops. Development of both rods and cones originates and proceeds most rapidly in the fundus or central region and proceeds toward the periphery. In general, rod outer segments were noted to develop far more rapidly than cone outer segments.

scholarly journals Rhodopsin in the rod outer segment plasma membrane.

1976 ◽  
Vol 69 (1) ◽  
pp. 29-42 ◽  
Author(s):  
S Basinger ◽  
D Bok ◽  
M Hall
Keyword(s):  
Plasma Membrane ◽  
Gel Electrophoresis ◽  
Visual Pigment ◽  
Outer Segment ◽  
Gel Filtration ◽  
Acid Mixture ◽  
Rod Outer Segments ◽  
Gel Filtration Chromatography ◽  
Rod Outer Segment ◽  
Outer Segments

Isolated frog retinas were incubated in vitro with a 4-h pulse of [3H]leucine, then chased for 32 h with a nonradioactive amino acid mixture. At the end of the incubation, light and electron microscope autoradiograms were prepared from some of the retinas. The autoradiograms revealed: (a) intense radioactivity in the basal disks of the rod outer segments, (b) diffuse label evenly distributed throughout the rod outer segments, and (c) a high concentration of label in the entire rod outer segment plasma membrane. Incubation under identical conditions, but with puromycin added, significantly inhibited the labeling of all of these components. To identify the labeled proteins, purified outer segments from the remaining retinas were analyzed biochemically by SDS disc gel electrophoresis and gel filtration chromatography. SDS gel electrophoresis showed that about 90% of the total rod outer segment radioactivity chromatographed coincident with visual pigment, suggesting that the radiolabeled protein in the plasma membrane is visual pigment. Gel filtration chromatography demonstrated that the radiolabeled protein co-chromatographed with rhodopsin rather than opsin, and that the newly synthesized visual pigment is both the basal disks and the plasma membrane is present in the native configuration.

Localization of kinesin superfamily proteins to the connecting cilium of fish photoreceptors

1996 ◽  
Vol 109 (4) ◽  
pp. 889-897 ◽  
Author(s):  
P.L. Beech ◽  
K. Pagh-Roehl ◽  
Y. Noda ◽  
N. Hirokawa ◽  
B. Burnside ◽  
...  
Keyword(s):  
Heavy Chain ◽  
Basal Body ◽  
Outer Segment ◽  
Rod Photoreceptors ◽  
Outer Segments ◽  
Immunological Tests ◽  
Peptide Antibody ◽  
N Terminus ◽  
Kinesin Superfamily ◽  
Rod Cell

Kinesin superfamily proteins (KIFs) are probable motors in vesicular and non-vesicular transport along microtubular tracks. Since a variety of KIFs have been recently identified in the motile flagella of Chlamydomonas, we sought to ascertain whether KIFs are also associated with the connecting cilia of vertebrate rod photoreceptors. As the only structural link between the rod inner segment and the photosensitive rod outer segment, the connecting cilium is thought to be the channel through which all material passes into and out of the outer segment from the rod cell body. We have performed immunological tests on isolated sunfish rod inner-outer segments (RIS-ROS) using two antibodies that recognize the conserved motor domain of numerous KIFs (anti-LAGSE, a peptide antibody, and anti-Klp1 head, generated against the N terminus of Chlamydomonas Klp1) as well as an antibody specific to a neuronal KIF, KIF3A. On immunoblots of RIS-ROS, LAGSE antibody detected a prominent band at approximately 117 kDa, which is likely to be kinesin heavy chain, and Klp1 head antibody detected a single band at approximately 170 kDa; KIF3A antibody detected a polypeptide at approximately 85 kDa which co-migrated with mammalian KIF3A and displayed ATP-dependent release from rod cytoskeletons. Immunofluorescence localizations with anti-LAGSE and anti-Klp1 head antibodies detected epitopes in the axoneme and ellipsoid, and immunoelectron microscopy with the LAGSE antibody showed that the connecting cilium region was particularly antigenic. Immunofluorescence with anti-KIF3A showed prominent labelling of the connecting cilium and the area surrounding its basal body; the outer segment axoneme and parts of the inner segment coincident with microtubules were also labelled. We propose that these putative kinesin superfamily proteins may be involved in the translocation of material between the rod inner and outer segments.

The photoreceptors and visual pigments in the retina of a boid snake, the ball python (Python regius)

1999 ◽  
Vol 202 (14) ◽  
pp. 1931-1938 ◽  
Author(s):  
A.J. Sillman ◽  
J.K. Carver ◽  
E.R. Loew
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Visual Pigment ◽  
Outer Segment ◽  
Visual Pigments ◽  
Single Type ◽  
Python Regius ◽  
Rods And Cones ◽  
Outer Segments ◽  
Scanning Electron

The photoreceptors and visual pigments of Python regius were studied using microspectrophotometry and scanning electron microscopy. The retina contains rods and cones, with rods constituting at least 90 % of the photoreceptor population. The rods are of a single type with long, narrow outer segments and are tightly packed. The wavelength of maximum absorbance (λ max) of the visual pigment in the rods is in the region of 494 nm. Two distinct types of cone are present. The most common cone, with a stout but stubby outer segment, contains a visual pigment with λ max at approximately 551 nm. A relatively rare cone, with a long, slender outer segment, contains an ultraviolet-sensitive visual pigment with λ max at approximately 360 nm. All the visual pigments have chromophores based on vitamin A1. The results are discussed in relation to the behavior of P. regius.

scholarly journals Rhodopsin Gene Expression Determines Rod Outer Segment Size and Rod Cell Resistance to a Dominant-Negative Neurodegeneration Mutant

PLoS ONE ◽  
2012 ◽  
Vol 7 (11) ◽  
pp. e49889 ◽  
Author(s):  
Brandee A. Price ◽  
Ivette M. Sandoval ◽  
Fung Chan ◽  
Ralph Nichols ◽  
Ramon Roman-Sanchez ◽  
...  
Keyword(s):  
Gene Expression ◽  
Outer Segment ◽  
Dominant Negative ◽  
Cell Resistance ◽  
Rhodopsin Gene ◽  
Rod Outer Segment ◽  
Segment Size ◽  
Rod Cell

scholarly journals THE RENEWAL OF ROD AND CONE OUTER SEGMENTS IN THE RHESUS MONKEY

1971 ◽  
Vol 49 (2) ◽  
pp. 303-318 ◽  
Author(s):  
Richard W. Young
Keyword(s):  
Rhesus Monkey ◽  
Rhesus Monkeys ◽  
Outer Segment ◽  
Pigment Epithelium ◽  
Renewal Processes ◽  
Visual Cells ◽  
Rods And Cones ◽  
Outer Segments ◽  
Retinal Rod ◽  
Assembly Site

The renewal of retinal rod and cone outer segments has been studied by radioautography in rhesus monkeys examined 2 and 4 days after injection of leucine-3H. The cell outer segment consists of a stack of photosensitive, membranous discs. In both rods and cones some of the newly formed (radioactive) protein became distributed throughout the outer segment. Furthermore, in rods (but not in cones), there was a transverse band of concentrated radioactive protein slightly above the outer segment base 2 days after injection. This was due to the formation of new discs, into which labeled protein had been incorporated. At 4 days, these radioactive discs were located farther from the outer segment base. Repeated assembly of new discs had displaced them away from the basal assembly site and along the outer segment. Measurements of the displacement rate indicated that each retinal rod produces 80–90 discs per day, and that the entire complement of outer segment discs is replaced every 9–13 days. To compensate for the continual formation of new discs, groups of old discs are intermittently shed from the apical end of the cell and phagocytized by the pigment epithelium. Each pigment epithelial cell engulfs and destroys about 2000–4000 rod outer segment discs daily. The similarity between visual cells in the rhesus monkey and those in man suggests that the same renewal processes occur in the human retina.

Subcellular localization of phosducin in rod photoreceptors

2005 ◽  
Vol 22 (1) ◽  
pp. 19-25 ◽  
Author(s):  
JING CHEN ◽  
TATSURO YOSHIDA ◽  
KOICHI NAKANO ◽  
MARK W. BITENSKY
Keyword(s):  
Subcellular Localization ◽  
Dark Adaptation ◽  
Outer Segment ◽  
Photoreceptor Cells ◽  
Immunogold Labeling ◽  
Synaptic Function ◽  
Immunogold Electron Microscopy ◽  
Rod Photoreceptors ◽  
Relative Paucity

Phosducin (Pd) is a 28-kD phosphoprotein whose expression in retina appears limited to photoreceptor cells. Pd binds to the β,γ subunits of transducin (Gt). Their binding affinity is markedly diminished by Pd phosphorylation. While Pd has long been regarded as a candidate for the regulation of Gt, the molecular details of Pd function remain unclear. This gap in understanding is due in part to a lack of precise information concerning the total amount and subcellular localization of rod Pd. While earlier studies suggested that Pd was a rod outer segment (ROS) protein, recent findings have demonstrated that Pd is distributed throughout the rod. In this report, the subcellular distribution and amounts of rat Pd are quantified with immunogold electron microscopy. After light or dark adaptation, retinal tissues were fixedin situand prepared for ultrathin sectioning and immunogold labeling. Pd concentrations were analyzed over the entire length of the rod. The highest Pd labeling densities were found in the rod synapse. Less intense Pd staining was observed in the ellipsoid and myoid regions, while minimal labeling densities were found in the ROS and the rod nucleus. In contrast with rod Gt, no evidence was found for light-dependent movement of Pd between inner and outer segments. There is a relative paucity of Pd in the ROS as compared with the large amounts of Gtfound there. This does not support the earlier idea that Pd could modulate Gtactivity by controlling its concentration. On the other hand, the presence of Pd in the nucleus is consistent with its possible role as a regulator of transcription. The functions of Pd in the ellipsoid and myoid regions remain unclear. The highest concentration of Pd was found at the rod synapse, consistent with a suggested role for Pd in the regulation of synaptic function.

scholarly journals Genetic rescue models refute nonautonomous rod cell death in retinitis pigmentosa

2017 ◽  
Vol 114 (20) ◽  
pp. 5259-5264 ◽  
Author(s):  
Susanne F. Koch ◽  
Jimmy K. Duong ◽  
Chun-Wei Hsu ◽  
Yi-Ting Tsai ◽  
Chyuan-Sheng Lin ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Retinitis Pigmentosa ◽  
High Efficiency ◽  
Genetic Rescue ◽  
Rod Photoreceptors ◽  
Rods And Cones ◽  
Promising Treatment ◽  
Low Efficiency ◽  
Rod Cell

Retinitis pigmentosa (RP) is an inherited neurodegenerative disease, in which the death of mutant rod photoreceptors leads secondarily to the non-cell autonomous death of cone photoreceptors. Gene therapy is a promising treatment strategy. Unfortunately, current methods of gene delivery treat only a fraction of diseased cells, yielding retinas that are a mosaic of treated and untreated rods, as well as cones. In this study, we created two RP mouse models to test whether dying, untreated rods negatively impact treated, rescued rods. In one model, treated and untreated rods were segregated. In the second model, treated and untreated rods were diffusely intermixed, and their ratio was controlled to achieve low-, medium-, or high-efficiency rescue. Analysis of these mosaic retinas demonstrated that rescued rods (and cones) survive, even when they are greatly outnumbered by dying photoreceptors. On the other hand, the rescued photoreceptors did exhibit long-term defects in their outer segments (OSs), which were less severe when more photoreceptors were treated. In summary, our study suggests that even low-efficiency gene therapy may achieve stable survival of rescued photoreceptors in RP patients, albeit with OS dysgenesis.

scholarly journals Control of the cyclic GMP phosphodiesterase of frog photoreceptor membranes.

1980 ◽  
Vol 76 (5) ◽  
pp. 631-645 ◽  
Author(s):  
P R Robinson ◽  
S Kawamura ◽  
B Abramson ◽  
M D Bownds
Keyword(s):  
Light Intensity ◽  
Cyclic Gmp ◽  
Outer Segment ◽  
Calcium Concentration ◽  
Light Adaptation ◽  
Light Sensitivity ◽  
Change Mechanism ◽  
Outer Segments ◽  
Labile Component ◽  
Photoreceptor Membranes

The light-activated cyclic GMP phosphodiesterase (PDE) of frog photoreceptor membranes has been assayed in isolated outer segments suspended in a low-calcium Ringer's solution. Activation occurs over a range of light intensity that also causes a decrease in the permeability, cyclic GMP levels, and GTP levels of isolated outer segments. At intermediate intensities, PDE activity assumes constant intermediate values determined by the rate of rhodopsin bleaching. Washing causes an increase in maximal enzyme activity. Increasing light intensity from darkness to a level bleaching 5 x 10(3) rhodopsin molecules per outer segment per second shifts the apparent Michaelis constant (Km) from 100 to 900 microM. Maximum enzyme velocity increases at least 10-fold. The component that normally regulates this light-induced increase in the Km of PDE is removed by the customary sucrose flotation procedures. The presence of 10(-3) M Ca++ increases the light sensitivity of PDE, and maximal activation is caused by illumination bleaching only 5 x 10(2) rhodopsin molecules per outer segment per second. Calcium acts by increasing enzyme velocity while having little influence on Km. The effect of calcium appears to require a labile component, sensitive to aging of the outer segment preparation. The decrease in the light sensitivity of PDE that can be observed upon lowering the calcium concentration may be related to the desensitization of the permeability change mechanism that occurs during light adaptation of rod photoreceptors.

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