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 determinations of rod visual pigments in some adult and larval Australian amphibians

1992 ◽  
Vol 9 (2) ◽  
pp. 137-142 ◽  
Author(s):  
J. C. Partridge ◽  
P. Speare ◽  
J. Shand ◽  
W. R. A. Muntz ◽  
D. McB. Williams
Keyword(s):  
Absorption Spectra ◽  
Visual Pigment ◽  
Visual Pigments ◽  
Anuran Amphibians

AbstractVisual pigments from the red rods of adults of eight species of Australian anuran amphibians, from a variety of habitats, were analyzed by microspectrophotometry. The λmax in all cases fell between 502 nm and 506 nm, and the absorption spectra were well fitted by an A1-based visual pigment template curve. Red rod pigments were also analyzed for a number of tadpoles. In some cases the data were best fitted with an A1based visual pigment template, in other cases with an A2-based template, and finally some tadpoles appeared to have mixtures of the two pigments.

scholarly journals Adaptation of a deep-sea cephalopod to the photic environment. Evidence for three visual pigments.

1988 ◽  
Vol 92 (1) ◽  
pp. 55-66 ◽  
Author(s):  
S Matsui ◽  
M Seidou ◽  
S Horiuchi ◽  
I Uchiyama ◽  
Y Kito
Keyword(s):  
Deep Sea ◽  
Visual Pigment ◽  
Small Area ◽  
High Performance ◽  
Outer Segment ◽  
High Sensitivity ◽  
Photoreceptor Cells ◽  
High Performance Liquid Chromatographic ◽  
Visual Pigments ◽  
Environmental Light

Watasenia scintillans, a bioluminescent deep-sea squid, has a specially developed eye with a large open pupil and three visual pigments. Photoreceptor cells (outer segment: 476 micron; inner segment: 99 micron) were long in the small area of the ventral retina receiving downwelling light, whereas they were short (outer segment: 207 micron; inner segment: 44 micron) in the other regions of the retina. The short photoreceptor cells contained the visual pigment with retinal (lambda max approximately 484 nm), probably for the purpose of adapting to their environmental light. The outer segment of the long photoreceptor cells consisted of two strata, a pinkish proximal area and a yellow distal area. The visual pigment with 3-dehydroretinal (lambda max approximately 500 nm) was located in the pinkish proximal area, giving high sensitivity at longer wavelengths. A newly found pigment (lambda max approximately 471 nm) was in the yellow distal area. The small area of the ventral retina containing two visual pigments is thought to have a high and broad spectral sensitivity, which is useful for distinguishing the bioluminescence of squids of the same species in their environmental downwelling light. These findings were obtained by partial bleaching of the extracted pigment from various areas of the retina and by high-performance liquid chromatographic analysis of the chromophore, complemented by microscopic observations.

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 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.

Mechanism of anionic coordination dimerization of isoprene

1981 ◽  
Vol 46 (7) ◽  
pp. 1600-1606 ◽  
Author(s):  
Jan Bartoň ◽  
Karel Volka ◽  
Miroslav Kašpar ◽  
Vlastimil Růžička
Keyword(s):  
Gas Chromatography ◽  
Alkali Metal ◽  
Absorption Spectra ◽  
Visible Radiation ◽  
Absorption Bands ◽  
Absorption Spectrophotometry ◽  
Spectrophotometric Data ◽  
Oligomeric Forms

The mechanism of controlled anionic coordination dimerization of isoprene (i.e. 2-methyl-1,3-butadiene) in the system tetrahydrofuran-isoprene-alkali metal-dialkylamine was investigated by using absorption spectrophotometry in the range of visible radiation and gas chromatography. The effect of the alkali metal (Li, Na, K) and dialkylamine (dicyclohexylamine, N-isopropylcyclohexylamine, N-methylisopropylamine) on the absorption spectra was tested. By comparing chromatographic and spectrophotometric data, the absorption bands in the range of visible radiation were identified with the existence of π-complexes between oligomeric forms of isoprene and alkali metal dialkylamide.

scholarly journals Unraveling the electrochemical and spectroscopic properties of neutral and negatively charged perylene tetraethylesters

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Christian Wiebeler ◽  
Joachim Vollbrecht ◽  
Adam Neuba ◽  
Heinz-Siegfried Kitzerow ◽  
Stefan Schumacher
Keyword(s):  
Absorption Spectra ◽  
Density Functional ◽  
Energy Levels ◽  
Spectroscopic Properties ◽  
Absorption Bands ◽  
Functional Theory ◽  
Vertical Excitation ◽  
Hartree Fock ◽  
Tauc Plot ◽  
Electrochemical Approach

AbstractA detailed investigation of the energy levels of perylene-3,4,9,10-tetracarboxylic tetraethylester as a representative compound for the whole family of perylene esters was performed. It was revealed via electrochemical measurements that one oxidation and two reductions take place. The bandgaps determined via the electrochemical approach are in good agreement with the optical bandgap obtained from the absorption spectra via a Tauc plot. In addition, absorption spectra in dependence of the electrochemical potential were the basis for extensive quantum-chemical calculations of the neutral, monoanionic, and dianionic molecules. For this purpose, calculations based on density functional theory were compared with post-Hartree–Fock methods and the CAM-B3LYP functional proved to be the most reliable choice for the calculation of absorption spectra. Furthermore, spectral features found experimentally could be reproduced with vibronic calculations and allowed to understand their origins. In particular, the two lowest energy absorption bands of the anion are not caused by absorption of two distinct electronic states, which might have been expected from vertical excitation calculations, but both states exhibit a strong vibronic progression resulting in contributions to both bands.

What Makes Red Visual Pigments Red? A Resonance Raman Microprobe Study of Retinal Chromophore Structure in Iodopsin

Biochemistry ◽  
1994 ◽  
Vol 33 (8) ◽  
pp. 2151-2160 ◽  
Author(s):  
Steven W. Lin ◽  
Yasushi Imamoto ◽  
Yoshitaka Fukada ◽  
Yoshinori Shichida ◽  
Toru Yoshizawa ◽  
...  
Keyword(s):  
Resonance Raman ◽  
Visual Pigments ◽  
Raman Microprobe ◽  
Retinal Chromophore

Excitonic Bands in the Optical Absorption Spectra of A3MX6 and A3M2X9 (A = MeNH3, Me2NH2, Me3NH, Me4N; M = Bi, Sb; X = Cl, Br, I)

1994 ◽  
Vol 49 (6) ◽  
pp. 849-851 ◽  
Author(s):  
G. C. Papavassiliou ◽  
I. B. Koutselas
Keyword(s):  
Optical Absorption ◽  
Absorption Spectra ◽  
Spectral Region ◽  
Visible Spectral Region ◽  
Optical Absorption Spectra ◽  
Absorption Bands ◽  
Uv Visible ◽  
Low Dimensional

The title compounds (natural low-dimensional semiconductors) show strong excitonic optical absorption bands in the UV-visible spectral region, because of the dielectric confinement of excitons. as in the cases of other similar systems based on PbX2-4, SnX2-4. PtI - X - PtIV-X , Cdx,Sy-clusters etc

The effect of extrinsic factors on two distinctive rhodopsin–porphyropsin systems

1977 ◽  
Vol 55 (6) ◽  
pp. 1000-1009 ◽  
Author(s):  
William N. McFarland ◽  
Donald M. Allen
Keyword(s):  
Visual Pigment ◽  
Brook Trout ◽  
Pigment Epithelium ◽  
Cold Treatment ◽  
Continuous Light ◽  
Photoreceptor Cells ◽  
Pigment Composition ◽  
Extrinsic Factors ◽  
Treatment Groups ◽  
Species Groups

The effects of light, temperature, and thyroxine on the proportions of two visual pigments (rhodopsin and porphyropsin) are compared for three species of fishes in which the pigment proportions change oppositely in response to light (rainbow and brook trout vs. common shiners). In rainbow trout and common shiners higher temperatures reduced the proportions of porphyropsin in the retina, independent of photic conditions. The greatest differences between the warm and cold treatment groups, however, were obtained with a photoperiod as contrasted with continuous light or darkness. Capping of one eye in brook trout reduced porphyropsin independently of the uncapped eye. Thyroxine, which favors porphyropsin in both species groups, acted effectively only in the presence of light. It is suggested that a photoperiod, which produces both bleaching and photomechanical movements within the retina, enhances the exchange of vitamin A1 and A2 aldehydes between the photoreceptor cells and the pigment epithelium. Apparently light influences these processes oppositely in the different groups of fishes. A model to explain how photic conditions affect visual pigment composition in tadpoles (Bridges 1975) is extended to account for the opposite responses to light and darkness observed in different fishes.

Spectral absorbance, structure, and population density of photoreceptors in the retina of the lake sturgeon (Acipenser fulvescens)

2007 ◽  
Vol 85 (4) ◽  
pp. 584-587 ◽  
Author(s):  
A.J. Sillman ◽  
E.K. Ong ◽  
E.R. Loew
Keyword(s):  
Visual Pigment ◽  
Visual Pigments ◽  
Lake Sturgeon ◽  
Acipenser Fulvescens ◽  
Long Wavelength ◽  
Rods And Cones ◽  
The North ◽  
Spectral Absorbance ◽  
Dim Light ◽  
Scanning Electron

Lake sturgeon ( Acipenser fulvescens Rafinesque, 1817) photoreceptors were studied with scanning electron microscopy and microspectrophotometry. The retina contains both rods and cones, with cones estimated composing about 30% of the photoreceptor population. Only large single cones were identified and they are similar to those found in other species of the order Acipenseriformes. The rods are large, with long, broad outer segments, and are similar to the dominant rod found in other sturgeons and the North American paddlefish ( Polyodon spathula (Walbaum, 1792)). Mean (SD) rod packing density at 22 624 ± 3 509 rods/mm2 is low compared with those of other animals that function primarily in dim light. The visual pigment of the rods has a mean (SD) peak absorbance (λmax) at 541 ± 2 nm. Three different cone populations were identified: a long wavelength sensitive cone containing a visual pigment with λmax at 619 ± 3 nm; middle wavelength sensitive cone with λmax at 538 ± 1 nm; and short wavelength sensitive cone with λmax at 448 ± 1 nm. All the visual pigments are based on the vitamin A2 chromophore.

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