S cones: Evolution, retinal distribution, development, and spectral sensitivity

2013 ◽  
Vol 31 (2) ◽  
pp. 115-138 ◽  
Author(s):  
DAVID M. HUNT ◽  
LEO PEICHL
Keyword(s):  
Spectral Sensitivity ◽  
Spectral Characteristics ◽  
Primary Role ◽  
Long Wavelength ◽  
Representative Species ◽  
Cone Pathway ◽  
Cone Development ◽  
High Acuity ◽  
Retinal Distribution

AbstractS cones expressing the short wavelength-sensitive type 1 (SWS1) class of visual pigment generally form only a minority type of cone photoreceptor within the vertebrate duplex retina. Hence, their primary role is in color vision, not in high acuity vision. In mammals, S cones may be present as a constant fraction of the cones across the retina, may be restricted to certain regions of the retina or may form a gradient across the retina, and in some species, there is coexpression of SWS1 and the long wavelength-sensitive (LWS) class of pigment in many cones. During retinal development, SWS1 opsin expression generally precedes that of LWS opsin, and evidence from genetic studies indicates that the S cone pathway may be the default pathway for cone development. With the notable exception of the cartilaginous fishes, where S cones appear to be absent, they are present in representative species from all other vertebrate classes. S cone loss is not, however, uncommon; they are absent from most aquatic mammals and from some but not all nocturnal terrestrial species. The peak spectral sensitivity of S cones depends on the spectral characteristics of the pigment present. Evidence from the study of agnathans and teleost fishes indicates that the ancestral vertebrate SWS1 pigment was ultraviolet (UV) sensitive with a peak around 360 nm, but this has shifted into the violet region of the spectrum (>380 nm) on many separate occasions during vertebrate evolution. In all cases, the shift was generated by just one or a few replacements in tuning-relevant residues. Only in the avian lineage has tuning moved in the opposite direction, with the reinvention of UV-sensitive pigments.

scholarly journals Inhibition of p53 Transactivation Function by the Human T-Cell Lymphotropic Virus Type 1 Tax Protein

1998 ◽  
Vol 72 (2) ◽  
pp. 1165-1170 ◽  
Author(s):  
Cynthia A. Pise-Masison ◽  
Kyeong-Sook Choi ◽  
Michael Radonovich ◽  
Jürgen Dittmer ◽  
Seong-Jin Kim ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Lines ◽  
Virus Type ◽  
Primary Role ◽  
Wild Type ◽  
Transformed Cell ◽  
Human T Cell ◽  
Wild Type P53 ◽  
Transformed Cell Lines

ABSTRACT Human T-cell lymphotropic virus type 1 (HTLV-1) is the etiologic agent for adult T-cell leukemia. HTLV-1 transforms lymphocytes, and there is increasing evidence that the virus-encoded protein, Tax, plays a primary role in viral transformation. We have shown that wild-type p53 in HTLV-1-transformed cells is stabilized. This study was initiated to directly analyze whether the p53 in HTLV-1-transformed cell lines was transcriptionally active and to identify the viral gene product responsible for stabilization and inactivation. Transfection experiments using a p53-responsive reporter plasmid and γ-irradiation studies demonstrate that the wild-type p53 in HTLV-1-transformed cell lines is not fully active. Further, we demonstrate that the HTLV-1-transforming protein, Tax, stabilizes and inactivates p53 function. Cotransfection of Tax with p53 results in a greater than 10-fold reduction in p53 transcription activity. Using Gal4-p53 fusion proteins, we demonstrate that Tax inhibition of p53 transactivation function is independent of sequence-specific DNA binding. Moreover, Tax inhibits p53 function by interfering with the activity of the N-terminal activation domain (amino acids 1 to 52). We conclude that Tax is involved in the inactivation of p53 function and stabilization of p53 in HTLV-1-infected cells. The functional interference of p53 function by Tax may be important for transformation and leukemogenesis.

An anomaly in the response of the eye to light of short wavelengths

1977 ◽  
Vol 278 (960) ◽  
pp. 207-240 ◽  
Keyword(s):  
Field Experiment ◽  
Spectral Sensitivity ◽  
Large Range ◽  
Fusion Frequency ◽  
Long Wavelength ◽  
Human Eye ◽  
Vision Experiment ◽  
Wavelength Light

Adaptation of the human eye to long-wavelength light leaves it insensitive to short-wavelengths: a blue flash that is visible in the presence of a yellow adapting field may remain invisible for several seconds after the field has been turned off (see experiment 1 and Appendix). This ‘transient tritanopia’ occurs for a large range of adapting intensities, but is abolished if the adapting field is very bright (experiment 2). The loss of sensitivity is primarily confined to the blue-sensitive cone mechanism (experiments 2 a , 3 and 4 ; and Appendix) and can be produced by small attenuations of the adapting field (experiment 5). It occurs in both foveal and parafoveal vision (experiment 6) but is absent when adapting and test stimuli are presented to opposite eyes (experiment 7). It was found in a protanope (experiment 9 a ) and, in a modified form, in a deuteranope (experiment 9 b ). No differences in sensitivity were found for blue flashes presented in the light and dark phases of a field flickering at a rate above the fusion frequency (Appendix). The sensitivity of the blue-sensitive mechanism of the eye appears to be controlled not only by quanta absorbed by the blue receptors but also by a mechanism with a different spectral sensitivity

Molecular Evidence of Long Wavelength Spectral Sensitivity in the Reverse Sexually Dichromatic Convict Cichlid (Amatitlania nigrofasciata)

Copeia ◽  
2015 ◽  
Vol 103 (3) ◽  
pp. 546-551 ◽  
Author(s):  
Kaitlin J. Fisher ◽  
Danielle L. Recupero ◽  
Aaron W. Schrey ◽  
Matthew J. Draud
Keyword(s):  
Spectral Sensitivity ◽  
Molecular Evidence ◽  
Convict Cichlid ◽  
Long Wavelength ◽  
Amatitlania Nigrofasciata

Spectral sensitivity of the feedback signal from horizontal cells to cones in goldfish retina

1998 ◽  
Vol 15 (5) ◽  
pp. 799-808 ◽  
Author(s):  
D.A. KRAAIJ ◽  
M. KAMERMANS ◽  
H. SPEKREIJSE
Keyword(s):  
Spectral Sensitivity ◽  
Horizontal Cell ◽  
Horizontal Cells ◽  
Feedback Signal ◽  
Cell Systems ◽  
Long Wavelength ◽  
Cell Recording ◽  
Cone System ◽  
Goldfish Retina ◽  
Uv Range

The spectral sensitivity of cones in isolated goldfish retina was determined with whole-cell recording techniques. Three spectral classes of cones were found with maximal sensitivities around 620 nm, 540 nm, and 460 nm. UV-cones were not found because our stimulator did not allow effective stimulation in the UV range. The spectral sensitivity of the cones closely matched the cone photopigment absorption spectra at the long wavelength side of the spectrum, but deviated significantly at shorter wavelengths. Surround stimulation induced an inward current in cones due to feedback from horizontal cells. The spectral sensitivity of this feedback signal was determined in all three cone classes and found to be broader than the spectral sensitivity of the cones recorded from, and to be spectrally nonopponent. These data are consistent with a connectivity scheme between cones and horizontal cells in which the three horizontal cell systems feed back to all cone systems and in which all horizontal cell systems receive input from more than one cone system.

APB differentially affects the cone contributions to the zebrafish ERG

2002 ◽  
Vol 19 (4) ◽  
pp. 521-529 ◽  
Author(s):  
SHANNON SASZIK ◽  
AMBER ALEXANDER ◽  
TIMOTHY LAWRENCE ◽  
JOSEPH BILOTTA
Keyword(s):  
Glutamate Receptors ◽  
Spectral Sensitivity ◽  
Visual Processing ◽  
Short Wavelength ◽  
Wavelength Region ◽  
Wave Component ◽  
Adult Zebrafish ◽  
Short Wavelength Region ◽  
Long Wavelength ◽  
Sensitivity Functions

APB (DL-2-amino-4-phosphonobutyric acid) has been found to affect the retinal processing of many vertebrate species as evidenced by the suppression of the b-wave component of the electroretinogram (ERG). The present study examined the effects of APB on the cone contributions to the ERG response of adult zebrafish (Danio rerio). ERG responses were obtained from light-adapted adult zebrafish following intravitreal injection of either saline alone or saline with various concentrations of APB ranging from 10 μm to 500 μM. Visual stimuli were 200-ms flashes of various wavelengths and irradiances. Spectral sensitivity functions were calculated from the irradiance versus response amplitude functions of the a-, b-, and d-wave components of the ERG response. Saline had no effects on the ERG response. However, APB had differential effects on the sensitivity of the b- and d-wave components. The effects of APB on the b-wave component were most apparent in the ultraviolet and short-wavelength portions (320–440 nm) of the spectral sensitivity function, although the b-wave was not completely eliminated at these wavelengths. APB-treated subjects were found to possess the same cone mechanisms (L-M and M-S) in the middle- and long-wavelength areas of the spectrum as saline injected subjects, although absolute sensitivity was lower for the APB-injected subjects. Spectral sensitivity based on the d-wave response was affected by APB but only in the short-wavelength region. All results appear to be independent of the APB dose. These results support the notion that glutamate receptors play a specific role in zebrafish visual processing. In addition, the effects of APB support recent anatomical evidence that the zebrafish retina may possess different types of glutamate receptors.

scholarly journals Intermixing the OPN1LW and OPN1MW Genes Disrupts the Exonic Splicing Code Causing an Array of Vision Disorders

2021 ◽  
Author(s):  
Maureen Neitz ◽  
Jay Neitz
Keyword(s):  
Feedback Mechanism ◽  
Human Retina ◽  
Vision Disorders ◽  
Low Light ◽  
Long Wavelength ◽  
Rods And Cones ◽  
Light Levels ◽  
Refractive Development ◽  
High Acuity ◽  
Splicing Defects

The first step in seeing is light absorption by photopigment molecules expressed in the photore-ceptors of the retina. There are two types of photoreceptors in the human retina that are respon-sible for image formation, rods and cones. Except at very low light levels when rods are active, all vision is based on cones. Cones mediate high acuity vision and color vision. Furthermore, they are critically important in the visual feedback mechanism that regulates refractive development of the eye during childhood. The human retina contains a mosaic of three cone types, short-wavelength (S), long-wavelength (L) and middle-wavelength (M); however, the vast major-ity (~94%) are L and M cones. The OPN1LW and OPN1MW genes, located on the X-chromosome at Xq28, encode the protein component of the light-sensitive photopigments. Here we review mechanism by which splicing defects in these genes cause vision disorders.

scholarly journals The Spectral Sensitivity of Crayfish and Lobster Vision

1961 ◽  
Vol 44 (6) ◽  
pp. 1089-1102 ◽  
Author(s):  
Donald Kennedy ◽  
Merle S. Bruno
Keyword(s):  
Fresh Water ◽  
Spectral Sensitivity ◽  
Light Adaptation ◽  
Compound Eye ◽  
Monochromatic Light ◽  
Sensitivity Function ◽  
Visual Sensitivity ◽  
Long Wavelength ◽  
Cone Pigments ◽  
Sensitivity Data

(1) The spectral sensitivity function for the compound eye of the crayfish has been determined by recording the retinal action potentials elicited by monochromatic stimuli. Its peak lies at approximately 570 mµ. (2) Similar measurements made on lobster eyes yield functions with maxima in the region of 520 to 525 mµ, which agree well with the absorption spectrum of lobster rhodopsin if minor allowances are made for distortion by known screening pigments. (3) The crayfish sensitivity function, since it is unaffected by selective monochromatic light adaptation, must be determined by a single photosensitive pigment. The absorption maximum of this pigment may be inferred with reasonable accuracy from the sensitivity data. (4) The visual pigment of the crayfish thus has its maximum absorption displaced by 50 to 60 mµ towards the red end of the spectrum from that of the lobster and other marine crustacea. This shift parallels that found in both rod and cone pigments between fresh water and marine vertebrates. In the crayfish, however, an altered protein is responsible for the shift and not a new carotenoid chromophore as in the vertebrates. (5) The existence of this situation in a new group of animals (with photoreceptors which have been evolved independently from those of vertebrates) strengthens the view that there may be strong selection for long wavelength visual sensitivity in fresh water.

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