Visual pigments and spectral sensitivity of the diurnal gecko Gonatodes albogularis

1995 ◽  
Vol 177 (5) ◽  
Author(s):  
J.M. Ellingson ◽  
L.J. Fleishman ◽  
E.R. Loew
Keyword(s):  
Spectral Sensitivity ◽  
Visual Pigments

scholarly journals Single and Multiple Visual Systems in Arthropods

1968 ◽  
Vol 51 (2) ◽  
pp. 125-156 ◽  
Author(s):  
George Wald
Keyword(s):  
Spectral Sensitivity ◽  
Visual Pigment ◽  
Light Adaptation ◽  
Procambarus Clarkii ◽  
Color Discrimination ◽  
Visual Pigments ◽  
Green Crab ◽  
Spider Crab ◽  
Color Adaptation ◽  
Visual Systems

Extraction of two visual pigments from crayfish eyes prompted an electrophysiological examination of the role of visual pigments in the compound eyes of six arthropods. The intact animals were used; in crayfishes isolated eyestalks also. Thresholds were measured in terms of the absolute or relative numbers of photons per flash at various wavelengths needed to evoke a constant amplitude of electroretinogram, usually 50 µv. Two species of crayfish, as well as the green crab, possess blue- and red-sensitive receptors apparently arranged for color discrimination. In the northern crayfish, Orconectes virilis, the spectral sensitivity of the dark-adapted eye is maximal at about 550 mµ, and on adaptation to bright red or blue lights breaks into two functions with λmax respectively at about 435 and 565 mµ, apparently emanating from different receptors. The swamp crayfish, Procambarus clarkii, displays a maximum sensitivity when dark-adapted at about 570 mµ, that breaks on color adaptation into blue- and red-sensitive functions with λmax about 450 and 575 mµ, again involving different receptors. Similarly the green crab, Carcinides maenas, presents a dark-adapted sensitivity maximal at about 510 mµ that divides on color adaptation into sensitivity curves maximal near 425 and 565 mµ. Each of these organisms thus possesses an apparatus adequate for at least two-color vision, resembling that of human green-blinds (deuteranopes). The visual pigments of the red-sensitive systems have been extracted from the crayfish eyes. The horse-shoe crab, Limulus, and the lobster each possesses a single visual system, with λmax respectively at 520 and 525 mµ. Each of these is invariant with color adaptation. In each case the visual pigment had already been identified in extracts. The spider crab, Libinia emarginata, presents another variation. It possesses two visual systems apparently differentiated, not for color discrimination but for use in dim and bright light, like vertebrate rods and cones. The spectral sensitivity of the dark-adapted eye is maximal at about 490 mµ and on light adaptation, whether to blue, red, or white light, is displaced toward shorter wavelengths in what is essentially a reverse Purkinje shift. In all these animals dark adaptation appears to involve two phases: a rapid, hyperbolic fall of log threshold associated probably with visual pigment regeneration, followed by a slow, almost linear fall of log threshold that may be associated with pigment migration.

scholarly journals Coexpression of Two Visual Pigments in a Photoreceptor Causes an Abnormally Broad Spectral Sensitivity in the Eye of the ButterflyPapilio xuthus

2003 ◽  
Vol 23 (11) ◽  
pp. 4527-4532 ◽  
Author(s):  
Kentaro Arikawa ◽  
Shin Mizuno ◽  
Michiyo Kinoshita ◽  
Doekele G. Stavenga
Keyword(s):  
Spectral Sensitivity ◽  
Visual Pigments

scholarly journals Thermal and Spectral Sensitivities of Discrete Slow Potentials in Limulus Eye

1968 ◽  
Vol 52 (4) ◽  
pp. 584-599 ◽  
Author(s):  
Alan R. Adolph
Keyword(s):  
Spectral Sensitivity ◽  
Visual Pigments ◽  
Light Wavelength ◽  
Slow Potential ◽  
Potential Fluctuations ◽  
Near Ultraviolet ◽  
Irreversible Reduction ◽  
Increasing Temperature ◽  
Ultraviolet Energy ◽  
Time Decrease

The discrete, subthreshold, slow potential fluctuations (SPF's) which can be recorded intracellularly in Limulus ommatidia are sensitive to temperature and light wavelength. SPF frequency increases with increasing temperature (Q10 about 3.5) and light intensity. The effects are additive. SPF rise and decay time decrease with increasing temperature (Q10 between 2 and 3). There is a peak, near 520 nm, in the spectral sensitivity of SPF frequency. This peak may correspond to the wavelength of maximum absorption by rhodopsin in the ommatidia. Hydroxylamine produces a rapid, irreversible reduction of SPF frequency and amplitude perhaps owing to its action on the photopigment. The cornea and crystalline cones fluoresce (peak about 445 nm) when excited by near-ultraviolet energy (380 nm peak) and this fluorescence may influence SPF spectral sensitivity measurements. These findings suggest that the SPF's are the results of photolytic and thermolytic reactions occurring in the ommatidial visual pigments and that they have a role in the mechanisms which transduce light to electrical activity in the visual receptors.

scholarly journals Visual pigments in a palaeognath bird, the emu Dromaius novaehollandiae : implications for spectral sensitivity and the origin of ultraviolet vision

2016 ◽  
Vol 283 (1834) ◽  
pp. 20161063 ◽  
Author(s):  
Nathan S. Hart ◽  
Jessica K. Mountford ◽  
Wayne I. L. Davies ◽  
Shaun P. Collin ◽  
David M. Hunt
Keyword(s):  
Spectral Sensitivity ◽  
Visual Pigment ◽  
Spectral Characteristics ◽  
Bird Species ◽  
Visual Pigments ◽  
Ancestral State ◽  
Avian Evolution ◽  
Retinal Photoreceptors ◽  
Cone Type ◽  
Dromaius Novaehollandiae

A comprehensive description of the spectral characteristics of retinal photoreceptors in palaeognaths is lacking. Moreover, controversy exists with respect to the spectral sensitivity of the short-wavelength-sensitive-1 (SWS1) opsin-based visual pigment expressed in one type of single cone: previous microspectrophotometric (MSP) measurements in the ostrich ( Struthio camelus ) suggested a violet-sensitive (VS) SWS1 pigment, but all palaeognath SWS1 opsin sequences obtained to date (including the ostrich) imply that the visual pigment is ultraviolet-sensitive (UVS). In this study, MSP was used to measure the spectral properties of visual pigments and oil droplets in the retinal photoreceptors of the emu ( Dromaius novaehollandiae ). Results show that the emu resembles most other bird species in possessing four spectrally distinct single cones, as well as double cones and rods. Four cone and a single rod opsin are expressed, each an orthologue of a previously identified pigment. The SWS1 pigment is clearly UVS (wavelength of maximum absorbance [ λ max ] = 376 nm), with key tuning sites (Phe86 and Cys90) consistent with other vertebrate UVS SWS1 pigments. Palaeognaths would appear, therefore, to have UVS SWS1 pigments. As they are considered to be basal in avian evolution, this suggests that UVS is the most likely ancestral state for birds. The functional significance of a dedicated UVS cone type in the emu is discussed.

scholarly journals Thermal and Spectral Sensitivities of Discrete Slow Potentials in Limulus Eye

1968 ◽  
Vol 52 (3) ◽  
pp. 584-599 ◽  
Author(s):  
Alan R. Adolph
Keyword(s):  
Spectral Sensitivity ◽  
Visual Pigments ◽  
Light Wavelength ◽  
Slow Potential ◽  
Potential Fluctuations ◽  
Near Ultraviolet ◽  
Irreversible Reduction ◽  
Increasing Temperature ◽  
Ultraviolet Energy ◽  
Time Decrease

The discrete, subthreshold, slow potential fluctuations (SPF's) which can be recorded intracellularly in Limulus ommatidia are sensitive to temperature and light wavelength. SPF frequency increases with increasing temperature (Q10 about 3.5) and light intensity. The effects are additive. SPF rise and decay time decrease with increasing temperature (Q10 between 2 and 3). There is a peak, near 520 nm, in the spectral sensitivity of SPF frequency. This peak may correspond to the wavelength of maximum absorption by rhodopsin in the ommatidia. Hydroxylamine produces a rapid, irreversible reduction of SPF frequency and amplitude perhaps owing to its action on the photopigment. The cornea and crystalline cones fluoresce (peak about 445 nm) when excited by near-ultraviolet energy (380 nm peak) and this fluorescence may influence SPF spectral sensitivity measurements. These findings suggest that the SPF's are the results of photolytic and thermolytic reactions occurring in the ommatidial visual pigments and that they have a role in the mechanisms which transduce light to electrical activity in the visual receptors.

Fly photoreceptors I. Physical separation of two visual pigments in Calliphora retinula cells 1-6

1975 ◽  
Vol 190 (1099) ◽  
pp. 211-224 ◽  
Keyword(s):  
Spectral Sensitivity ◽  
Polarized Light ◽  
Visual Pigments ◽  
Polarization Sensitivity ◽  
Physical Separation ◽  
Adaptation Mechanisms ◽  
Sensitivity Curves ◽  
Peak Sensitivity ◽  
Two Peaks ◽  
Different Parts

The two peaks of the spectral sensitivity curves of Calliphora correspond to two visual pigments. The peak sensitivity to polarized light for the u. v. sensitive pigment is at an angle to that for the green-sensitive pigment. The change in angle of the maximum polarization sensitivity as a function of wavelength occurs near 400 nm; in this transition the curves do not follow a cos 2 function. The angle between the two maxima is different for each retinula cell. The only explanation of this phenomenon is that there are two visual pigments in different parts of the receptor, and one part is twisted relative to the other. There are therefore two metarhodopsins and the adaptation mechanisms are partially separate for the two peaks of the spectral sensitivity. The inference of two separated pigments modifies the interpretation of much previous work on fly photoreceptors.

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