scholarly journals Two visual pigments in a single photoreceptor cell: identification and histological localization of three mRNAs encoding visual pigment opsins in the retina of the butterfly Papilio xuthus.

1998 ◽  
Vol 201 (9) ◽  
pp. 1255-1261 ◽  
Author(s):  
J Kitamoto ◽  
K Sakamoto ◽  
K Ozaki ◽  
Y Mishina ◽  
K Arikawa
Keyword(s):  
In Situ Hybridization ◽  
Visual Pigment ◽  
Photoreceptor Cell ◽  
Wavelength Region ◽  
Photoreceptor Cells ◽  
Visual Pigments ◽  
Cell Identification ◽  
Papilio Xuthus

This paper describes the localization of newly identified visual pigment opsins in the tiered retina of the Japanese yellow swallowtail Papilio xuthus. We first cloned three cDNAs encoding visual pigment opsins, PxRh1, PxRh2 and PxRh3, and then carried out histological in situ hybridization to localize their mRNAs in the retina. By combining the present data with our previous electrophysiological results, we concluded that both PxRh1 and PxRh2 correspond to visual pigments expressed in photoreceptor cells sensitive in the green wavelength region (green receptors), whereas PxRh3 corresponds to a pigment in red receptors. The in situ hybridization studies showed that some photoreceptor cells express two opsin mRNAs. In the ventral half of the eye, all green receptors in the distal tier were labelled by both PxRh1 and PxRh2 probes. The labelling by the PxRh2 and PxRh3 probes was detected throughout the eye in the proximal tier; in 18 % of ommatidia, the probes labelled the same photoreceptor cell. These results suggest that the possible co-localization of two different visual pigments will broaden the sensitivity spectrum of the photoreceptor cells.

scholarly journals Ultraviolet and violet receptors express identical mRNA encoding an ultraviolet-absorbing opsin: identification and histological localization of two mRNAs encoding short-wavelength-absorbing opsins in the retina of the butterfly Papilio xuthus

2000 ◽  
Vol 203 (19) ◽  
pp. 2887-2894 ◽  
Author(s):  
J. Kitamoto ◽  
K. Ozaki ◽  
K. Arikawa
Keyword(s):  
Amino Acid ◽  
Visual Pigment ◽  
Short Wavelength ◽  
Photoreceptor Cells ◽  
Visual Pigments ◽  
Amino Acid Sequences ◽  
Papilio Xuthus ◽  
Different Types ◽  
Identical Amino Acid Sequence

This paper describes the primary structures of two opsins of short-wavelength-absorbing visual pigments deduced from the mRNA sequences in the retina of the Japanese yellow swallowtail butterfly Papilio xuthus. A phylogenetic analysis of the amino acid sequences indicates that one of these visual pigments is of the ultraviolet-absorbing type and that the other is of the blue-absorbing type. We identified the photoreceptor cells that express these mRNAs by histological in situ hybridization. The mRNA of the ultraviolet type is expressed in two distinct photoreceptor types previously identified as ultraviolet and violet receptors, providing the first molecular biological evidence that different types of spectral receptor probably express a visual pigment with an identical amino acid sequence. The mRNA of the blue type is expressed exclusively in cells classified as blue receptors.

scholarly journals The rhodopsin-retinochrome system for retinal re-isomerization predates the origin of cephalopod eyes

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Oliver Vöcking ◽  
Lucas Leclère ◽  
Harald Hausen
Keyword(s):  
In Situ Hybridization ◽  
Photoreceptor Cells ◽  
Visual Cycle ◽  
Phylogenetic Distribution ◽  
Enzymatic Process ◽  
Antibody Staining ◽  
The Individual ◽  
Functional Components ◽  
Visual Rhodopsin

Abstract Background The process of photoreception in most animals depends on the light induced isomerization of the chromophore retinal, bound to rhodopsin. To re-use retinal, the all-trans-retinal form needs to be re-isomerized to 11-cis-retinal, which can be achieved in different ways. In vertebrates, this mostly includes a stepwise enzymatic process called the visual cycle. The best studied re-isomerization system in protostomes is the rhodopsin-retinochrome system of cephalopods, which consists of rhodopsin, the photoisomerase retinochrome and the protein RALBP functioning as shuttle for retinal. In this study we investigate the expression of the rhodopsin-retinochrome system and functional components of the vertebrate visual cycle in a polyplacophoran mollusk, Leptochiton asellus, and examine the phylogenetic distribution of the individual components in other protostome animals. Results Tree-based orthology assignments revealed that orthologs of the cephalopod retinochrome and RALBP are present in mollusks outside of cephalopods. By mining our dataset for vertebrate visual cycle components, we also found orthologs of the retinoid binding protein RLBP1, in polyplacophoran mollusks, cephalopods and a phoronid. In situ hybridization and antibody staining revealed that L. asellus retinochrome is co-expressed in the larval chiton photoreceptor cells (PRCs) with the visual rhodopsin, RALBP and RLBP1. In addition, multiple retinal dehydrogenases are expressed in the PRCs, which might also contribute to the rhodopsin-retinochrome system. Conclusions We conclude that the rhodopsin-retinochrome system is a common feature of mollusk PRCs and predates the origin of cephalopod eyes. Our results show that this system has to be extended by adding further components, which surprisingly, are shared with vertebrates.

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.

scholarly journals Multiple visual pigments in a photoreceptor of the salamander retina.

1996 ◽  
Vol 108 (1) ◽  
pp. 27-34 ◽  
Author(s):  
C L Makino ◽  
R L Dodd
Keyword(s):  
Absorption Spectra ◽  
Visual Pigment ◽  
Photoreceptor Cells ◽  
Visual Pigments ◽  
Wavelength Band ◽  
Absorption Bands ◽  
Maximal Sensitivity ◽  
Retinal Chromophore ◽  
Wavelength Discrimination ◽  
Pigment Absorption

Although a given retina typically contains several visual pigments, each formed from a retinal chromophore bound to a specific opsin protein, single photoreceptor cells have been thought to express only one type of opsin. This design maximizes a cell's sensitivity to a particular wavelength band and facilitates wavelength discrimination in retinas that process color. We report electrophysiological evidence that the ultraviolet-sensitive cone of salamander violates this rule. This cell contains three different functional opsins. The three opsins could combine with the two different chromophores present in salamander retina to form six visual pigments. Whereas rods and other cones of salamander use both chromophores, they appear to express only one type of opsin per cell. In visual pigment absorption spectra, the bandwidth at half-maximal sensitivity increases as the pigment's wavelength maximum decreases. However, the bandwidth of the UV-absorbing pigment deviates from this trend; it is narrow like that of a red-absorbing pigment. In addition, the UV-absorbing pigment has a high apparent photosensitivity when compared with that of red- and blue-absorbing pigments and rhodopsin. These properties suggest that the mechanisms responsible for spectrally tuning visual pigments separate two absorption bands as the wavelength of maximal sensitivity shifts from UV to long wavelengths.

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.

Two opsins from the compound eye of the crab Hemigrapsus sanguineus

1996 ◽  
Vol 199 (2) ◽  
pp. 441-450 ◽  
Author(s):  
K Sakamoto ◽  
O Hisatomi ◽  
F Tokunaga ◽  
E Eguchi
Keyword(s):  
Photoreceptor Cell ◽  
Compound Eye ◽  
Visual Pigments ◽  
Amino Acid Residues ◽  
Hemigrapsus Sanguineus ◽  
Brachyuran Crab ◽  
Maximal Absorption ◽  
Retinular Cells ◽  
Cdna Nucleotide

The primary structures of two opsins from the brachyuran crab Hemigrapsus sanguineus were deduced from the cDNA nucleotide sequences. Both deduced proteins were composed of 377 amino acid residues and included residues highly conserved in visual pigments of other species, and the proteins were 75 % identical to each other. The distribution of opsin transcripts in the compound eye, determined by in situ hybridization, suggested that the mRNAs of the two opsins were expressed simultaneously in all of the seven retinular cells (R1-R7) forming the main rhabdom in each ommatidium. Two different visual pigments may be present in one photoreceptor cell in this brachyuran crab. The spectral sensitivity of the compound eye was also determined by recording the electroretinogram. The compound eye was maximally sensitive at about 480 nm. These and previous findings suggest that both opsins of this brachyuran crab produce visual pigments with maximal absorption in the blue-green region of the spectrum. Evidence is presented that crustaceans possess multiple pigment systems for vision.

scholarly journals Automated cone photoreceptor cell identification in confocal adaptive optics scanning laser ophthalmoscope images based on object detection

2021 ◽  
pp. 2250001
Author(s):  
Yiwei Chen ◽  
Yi He ◽  
Jing Wang ◽  
Wanyue Li ◽  
Lina Xing ◽  
...  
Keyword(s):  
Object Detection ◽  
Adaptive Optics ◽  
Photoreceptor Cell ◽  
Ground Truth ◽  
Photoreceptor Cells ◽  
Detection Algorithm ◽  
Scanning Laser Ophthalmoscope ◽  
Scanning Laser ◽  
Cone Photoreceptor ◽  
Cell Identification

Cone photoreceptor cell identification is important for the early diagnosis of retinopathy. In this study, an object detection algorithm is used for cone cell identification in confocal adaptive optics scanning laser ophthalmoscope (AOSLO) images. An effectiveness evaluation of identification using the proposed method reveals precision, recall, and [Formula: see text]-score of 95.8%, 96.5%, and 96.1%, respectively, considering manual identification as the ground truth. Various object detection and identification results from images with different cone photoreceptor cell distributions further demonstrate the performance of the proposed method. Overall, the proposed method can accurately identify cone photoreceptor cells on confocal adaptive optics scanning laser ophthalmoscope images, being comparable to manual identification.

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.

scholarly journals Co-expression of xenopsin and rhabdomeric opsin in photoreceptors bearing microvilli and cilia

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Oliver Vöcking ◽  
Ioannis Kourtesis ◽  
Sharat Chandra Tumu ◽  
Harald Hausen
Keyword(s):  
Visual Pigment ◽  
Photoreceptor Cell ◽  
Gene Loss ◽  
Photoreceptor Cells ◽  
Common Origin ◽  
Opsin Gene ◽  
Cell Type ◽  
Rods And Cones ◽  
Gene Structures ◽  
And Function

Ciliary and rhabdomeric opsins are employed by different kinds of photoreceptor cells, such as ciliary vertebrate rods and cones or protostome microvillar eye photoreceptors, that have specialized structures and molecular physiologies. We report unprecedented cellular co-expression of rhabdomeric opsin and a visual pigment of the recently described xenopsins in larval eyes of a mollusk. The photoreceptors bear both microvilli and cilia and express proteins that are orthologous to transporters in microvillar and ciliary opsin trafficking. Highly conserved but distinct gene structures suggest that xenopsins and ciliary opsins are of independent origin, irrespective of their mutually exclusive distribution in animals. Furthermore, we propose that frequent opsin gene loss had a large influence on the evolution, organization and function of brain and eye photoreceptor cells in bilaterian animals. The presence of xenopsin in eyes of even different design might be due to a common origin and initial employment of this protein in a highly plastic photoreceptor cell type of mixed microvillar/ciliary organization.

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