scholarly journals In search of the visual pigment template

2000 ◽  
Vol 17 (4) ◽  
pp. 509-528 ◽  
Author(s):  
VICTOR I. GOVARDOVSKII ◽  
NANNA FYHRQUIST ◽  
TOM REUTER ◽  
DMITRY G. KUZMIN ◽  
KRISTIAN DONNER
Keyword(s):  
Visual Pigment ◽  
Good Description ◽  
Visual Pigments ◽  
Rod Outer Segments ◽  
Absorbance Spectrum ◽  
Outer Segments ◽  
Bovine Rhodopsin ◽  
Α Band ◽  
Absorbance Spectra

Absorbance spectra were recorded by microspectrophotometry from 39 different rod and cone types representing amphibians, reptiles, and fishes, with A1- or A2-based visual pigments and λmax ranging from 357 to 620 nm. The purpose was to investigate accuracy limits of putative universal templates for visual pigment absorbance spectra, and if possible to amend the templates to overcome the limitations. It was found that (1) the absorbance spectrum of frog rhodopsin extract very precisely parallels that of rod outer segments from the same individual, with only a slight hypsochromic shift in λmax, hence templates based on extracts are valid for absorbance in situ; (2) a template based on the bovine rhodopsin extract data of Partridge and De Grip (1991) describes the absorbance of amphibian rod outer segments excellently, contrary to recent electrophysiological results; (3) the λmax/λ invariance of spectral shape fails for A1 pigments with small λmax and for A2 pigments with large λmax, but the deviations are systematic and can be readily incorporated into, for example, the Lamb (1995) template. We thus propose modified templates for the main “α-band” of A1 and A2 pigments and show that these describe both absorbance and spectral sensitivities of photoreceptors over the whole range of λmax. Subtraction of the α-band from the full absorbance spectrum leaves a “β-band” described by a λmax-dependent Gaussian. We conclude that the idea of universal templates (one for A1- and one for A2-based visual pigments) remains valid and useful at the present level of accuracy of data on photoreceptor absorbance and sensitivity. The sum of our expressions for the α- and β-band gives a good description for visual pigment spectra with λmax > 350 nm.

The photoreceptors and visual pigments in the retina of the white sturgeon, Acipenser transmontanus

1990 ◽  
Vol 68 (7) ◽  
pp. 1544-1551 ◽  
Author(s):  
A. J. Sillman ◽  
M. D. Spanfelner ◽  
E. R. Loew
Keyword(s):  
Vitamin A ◽  
Visual Pigment ◽  
Visual Pigments ◽  
Spectrophotometric Analysis ◽  
White Sturgeon ◽  
Acipenser Transmontanus ◽  
Light Regimen ◽  
Cone Pigment ◽  
Spectral Absorbance

The photoreceptors in the retina of the white sturgeon, Acipenser transmontanus (Chondrostei), were studied by means of scanning electron microscopy, in situ microspectrophotometry, and spectrophotometric analysis of visual pigment extracts. The white sturgeon retina is simple in that it contains only two morphologically distinct photoreceptors. The retina is dominated by rods with large outer segments, but there is a substantial population (40%) of single cones. Evidence was found for only one rod visual pigment and one cone visual pigment. Peak spectral absorbance (λmax) of the rod pigment is near 539 nm, whereas λmax of the cone pigment is near 605 nm. Both visual pigments are porphyropsin types with chromophores based on vitamin A2. No detectable rhodopsin based on vitamin A1 is ever present, regardless of season or light regimen. The results are discussed in terms of the sturgeon's behavior, as well as the implications for the evolution of color vision.

Single and multiple visual pigments in deep-sea fishes

1992 ◽  
Vol 72 (1) ◽  
pp. 113-130 ◽  
Author(s):  
J. C. Partridge ◽  
S. N. Archer ◽  
J. Vanoostrum
Keyword(s):  
Deep Sea ◽  
Visual Pigment ◽  
Short Wave ◽  
Visual Pigments ◽  
Outer Segments ◽  
Long Wave ◽  
Retinal Rods ◽  
Pigment Extract ◽  
Sea Fish

The visual pigments in the retinal rods of 17 species of deep-sea fish were examined by microspectrophotometry or visual pigment extract spectrophotometry. In 15 species single visual pigments were found with peak sensitivities between 470 and 490 nm, typical of deep-sea fishes. However, in one species, Stylephorons cordatus, two visual pigments were found with λ values at 470 and 481 nm. In another species, Scopelarchus analis, three visual pigments were found with mean λ values of 444, 479 and 505 nm. The short-wave pigment of this species was found both in main and accessory retinae. It was present both in single rods and in outer segments which had the most long-wave sensitive pigment in their distal parts. It is argued that these two-pigment rods are in the process of changing their visual pigment from a ‘juvenile’ VP505 pigment to an ‘adult’ VP444 pigment. The VP479 was found only as a single pigment in rods in the accessory retina.

Microspectrophotometric and immunocytochemical identification of ultraviolet photoreceptors in geckos

1996 ◽  
Vol 13 (2) ◽  
pp. 247-256 ◽  
Author(s):  
E. R. Loew ◽  
V. I. Govardovskii ◽  
P. Röhlich ◽  
Á. Szél
Keyword(s):  
Monoclonal Antibody ◽  
Visual Pigment ◽  
Photoreceptor Cell ◽  
Cell Types ◽  
Visual Pigments ◽  
Specific Monoclonal Antibody ◽  
Hemidactylus Turcicus ◽  
Bovine Rhodopsin ◽  
Type C ◽  
Polyclonal Serum

AbstractRetinas of the nocturnal geckos, Hemidactylus turcicus, Hemidactylus garnotii, and Teratoscincus scincus, were studied with microspectrophotometry and immunocytochemistry against various visual pigment epitopes to reveal UV-sensitive photoreceptors. From 6–20% of the thinner members of type C double photoreceptors, earlier believed to be blue-sensitive, were found to contain a UV-absorbing visual pigment with λmax at 363–366 nm. The pigment had bleaching and dichroic properties typical of other photoreceptor cell types of the retina. Presumptive UV-sensitive cells in retinal sections were “negatively” labeled as they did not react with either the cone-specific monoclonal antibody COS-1 or with the anti-rhodopsin polyclonal serum AO, which together labeled all of the remaining photoreceptor types (green-sensitive A singles, B doubles, and thicker members of C doubles, as well as the blue-sensitive majority of thinner members of C doubles). UV cells were moderately stained with the mAb K42–41 produced against the 5–6 loop of bovine rhodopsin, which also moderately labeled blue-sensitive cells. mAb OS-2 strongly stained all outer segments, including the UV-sensitive ones. Similarities between gecko UV visual pigments, and UV visual pigments of other vertebrates, as well as possible functional significance of these cells are discussed.

Visual pigment loss after light-induced shedding of rod outer segments

1976 ◽  
Vol 23 (6) ◽  
pp. 637-641 ◽  
Author(s):  
C.D.B. Bridges ◽  
Joe G. Hollyfield ◽  
Joseph C. Besharse ◽  
Mary E. Rayborn
Keyword(s):  
Visual Pigment ◽  
Rod Outer Segments ◽  
Outer Segments

scholarly journals Visual Pigments of Goldfish Cones

1974 ◽  
Vol 63 (3) ◽  
pp. 279-304 ◽  
Author(s):  
Ferenc I. Hárosi ◽  
Edward F. MacNichol
Keyword(s):  
Absorption Band ◽  
Oscillator Strength ◽  
Optical Density ◽  
Visual Pigment ◽  
Visual Pigments ◽  
Main Absorption Band ◽  
Dichroic Ratio ◽  
Outer Segments ◽  
Retinal Photoreceptors ◽  
Cone Pigments

Freshly isolated retinal photoreceptors of goldfish were studied microspectrophotometrically. Absolute absorptance spectra obtained from dark-adapted cone outer segments reaffirm the existence of three spectrally distinct cone types with absorption maxima at 455 ± 3,530 ± 3, and 625 ± 5 nm. These types were found often recognizable by gross cellular morphology. Side-illuminated cone outer segments were dichroic. The measured dichroic ratio for the main absorption band of each type was 2–3:1. Rapidly bleached cells revealed spectral and dichroic transitions in regions near 400–410, 435–455, and 350–360 nm. These photoproducts decay about fivefold as fast as the intermediates in frog rods. The spectral maxima of photoproducts, combined with other evidence, indicate that retinene2 is the chromophore of all three cone pigments. The average specific optical density for goldfish cone outer segments was found to be 0.0124 ± 0.0015/µm. The spectra of the blue-, and green-absorbing cones appeared to match porphyropsin standards with half-band width Δν = 4,832 ± 100 cm–1. The red-absorbing spectrum was found narrower, having Δν = 3,625 ± 100 cm–1. The results are consistent with the notion that visual pigment concentration within the outer segments is about the same for frog rods and goldfish cones, but that the blue-, and green-absorbing pigments possess molar extinctions of 30,000 liter/mol cm. The red-absorbing pigment was found to have extinction of 40,000 liter/mol cm, assuming invariance of oscillator strength among the three cone spectra.

The visual pigments of wild white sturgeon (Acipenser transmontanus)

1995 ◽  
Vol 73 (4) ◽  
pp. 805-809 ◽  
Author(s):  
A. J. Sillman ◽  
M. E. Sorsky ◽  
E. R. Loew
Keyword(s):  
Vitamin A ◽  
Fresh Water ◽  
Visual Pigment ◽  
Visual Pigments ◽  
White Sturgeon ◽  
Acipenser Transmontanus ◽  
Estuarine Water ◽  
Cone Pigments ◽  
Partial Bleaching

The visual pigments of the anadromous white sturgeon (Acipenser transmontanus) taken from relatively saline estuarine water were characterized by means of in situ microspectrophotometry and partial bleaching analysis of a digitonin extract. The three cone pigments (λmax = 605, 539, and ca. 460 nm) and one rod pigment (λmax = 541 nm) of the wild sturgeon are the same as those of cultured sturgeon that spend their entire lives in fresh water. All the visual pigments incorporate a chromophore based on vitamin A2. Unlike other anadromous fishes during the "saline phase," the white sturgeon shows no evidence of the presence of any vitamin A1 based visual pigment in the retina.

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.

scholarly journals Orientation of Intermediates in the Bleaching of Shear-Oriented Rhodopsin

1973 ◽  
Vol 62 (5) ◽  
pp. 509-522 ◽  
Author(s):  
Woodring E. Wright ◽  
Paul K. Brown ◽  
George Wald
Keyword(s):  
Visual Pigment ◽  
Room Temperature ◽  
Polarized Light ◽  
Rod Outer Segments ◽  
Outer Segments ◽  
The Asymmetry

Cattle rhodopsin can be highly oriented by shearing a wet paste of digitonin micelles of this visual pigment between two quartz slides. This orients the rhodopsin micelles so that their chromophores lie mainly parallel to the direction of shear. In such preparations the orientation of rhodopsin and intermediates of its bleaching by light have been measured with plane-polarized light from -195°C to room temperature. The chromophore maintains essentially the same orientation as in rhodopsin in all the intermediates of bleaching: bathorhodopsin (prelumirhodopsin), lumirhodopsin, and metarhodopsins I and II. When, however, the retinaldehyde chromophore is hydrolyzed from opsin in the presence of hydroxylamine, the retinaldehyde oxime that results rotates so as to lie mainly across the direction of shear. That is, the retinal oxime, though free, orients itself upon the oriented matrix of the opsin-digitonin micelles. These experiments show the rhodopsin-digitonin micelle to be markedly asymmetric, with the chromophore lying parallel to its long axis. The asymmetry could originate in the formation of the micelle, in rhodopsin itself, or by its linear polymerization under the conditions of the experiment. If rhodopsin itself is markedly asymmetric, for which there is some evidence, then, since in the rod outer segments its chromophores lie parallel to the disk membranes, the molecules themselves must lie with their long axes parallel to the membranes.

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