scholarly journals True UV color vision in a butterfly with two UV opsins

2020 ◽  
Author(s):  
Susan D. Finkbeiner ◽  
Adriana D. Briscoe
Keyword(s):  
Color Vision ◽  
Color Discrimination ◽  
List Type ◽  
Opsin Genes ◽  
Multiple Wavelengths ◽  
Yellow Corolla ◽  
Behavioral Evidence ◽  
Blue Range ◽  
Pollen Flowers ◽  
Wing Coloration

ABSTRACTTrue color vision in animals is achieved when wavelength discrimination occurs based on chromatic content of the stimuli, regardless of intensity. In order to successfully discriminate between multiple wavelengths, animals must use at least two photoreceptor types with different spectral sensitivity peaks.Heliconius butterflies have duplicate UV opsin genes, which encode two kinds of photoreceptors with peak sensitivities in the ultraviolet and violet, respectively. In H. erato, the ultraviolet photoreceptor is only expressed in females.Evidence from intracellular recordings suggests female H. erato may be able to discriminate between UV wavelengths, however, this has yet to be tested experimentally.Using an arena with a controlled light setting, we tested the ability of H. erato, and two species lacking the violet receptor, H. melpomene and outgroup Eueides isabella, to discriminate between two ultraviolet wavelengths, 380 and 390 nm, as well as two blue wavelengths, 400 and 436 nm, after being trained to associate each stimulus with a food reward. Wavelength stimuli were presented in varying intensities to rule out brightness as a cue.We found that H. erato females were the only butterflies capable of color vision in the UV range; the other butterflies had an intensity-dependent preference for UV stimuli. Across species, both sexes showed color vision in the blue-range.Models of H. erato color vision suggest that females have an advantage over males in discriminating the inner UV-yellow corolla of Psiguria pollen flowers from the surrounding outer orange petals, while previous models (McCulloch et al. 2017) suggested that H. erato males have an advantage over females in discriminating Heliconius 3-hyroxykynurenine (3-OHK) yellow wing coloration from non-3-OHK yellow wing coloration found in mimics.These results provide some of the first behavioral evidence for UV color discrimination in Heliconius females in the context of foraging, lending support to the hypothesis (Briscoe et al. 2010) that the duplicated UV opsin genes function together in UV color vision. Taken together, the sexually dimorphic visual system of H. erato appears to have been shaped by both sexual selection and sex-specific natural selection.

True UV color vision in a female butterfly with two UV opsins

2021 ◽  
Vol 224 (18) ◽  
Author(s):  
Susan D. Finkbeiner ◽  
Adriana D. Briscoe
Keyword(s):  
Color Vision ◽  
Color Discrimination ◽  
Sexually Dimorphic ◽  
Heliconius Melpomene ◽  
Opsin Genes ◽  
Behavioral Evidence ◽  
Blue Range ◽  
True Color ◽  
Wing Coloration ◽  
Uv Range

ABSTRACT In true color vision, animals discriminate between light wavelengths, regardless of intensity, using at least two photoreceptors with different spectral sensitivity peaks. Heliconius butterflies have duplicate UV opsin genes, which encode ultraviolet and violet photoreceptors, respectively. In Heliconius erato, only females express the ultraviolet photoreceptor, suggesting females (but not males) can discriminate between UV wavelengths. We tested the ability of H. erato, and two species lacking the violet receptor, Heliconius melpomene and Eueides isabella, to discriminate between 380 and 390 nm, and between 400 and 436 nm, after being trained to associate each stimulus with a sugar reward. We found that only H. erato females have color vision in the UV range. Across species, both sexes show color vision in the blue range. Models of H. erato color vision suggest that females have an advantage over males in discriminating the inner UV-yellow corollas of Psiguria flowers from their outer orange petals. Moreover, previous models ( McCulloch et al., 2017) suggested that H. erato males have an advantage over females in discriminating Heliconius 3-hydroxykynurenine (3-OHK) yellow wing coloration from non-3-OHK yellow wing coloration found in other heliconiines. These results provide some of the first behavioral evidence for female H. erato UV color discrimination in the context of foraging, lending support to the hypothesis ( Briscoe et al., 2010) that the duplicated UV opsin genes function together in UV color vision. Taken together, the sexually dimorphic visual system of H. erato appears to have been shaped by both sexual selection and sex-specific natural selection.

Bipolar cell pathways for color vision in non-primate dichromats

2010 ◽  
Vol 28 (1) ◽  
pp. 51-60 ◽  
Author(s):  
CHRISTIAN PULLER ◽  
SILKE HAVERKAMP
Keyword(s):  
Color Vision ◽  
Bipolar Cell ◽  
Ganglion Cells ◽  
Color Discrimination ◽  
Model Systems ◽  
Retinal Ganglion ◽  
Retinal Pathways ◽  
Retinal Information Processing ◽  
Cone Opsins ◽  
Retinal Information

AbstractColor vision in mammals is based on the expression of at least two cone opsins that are sensitive to different wavelengths of light. Furthermore, retinal pathways conveying color-opponent signals are required for color discrimination. Most of the primates are trichromats, and “color-coded channels” of their retinas are unveiled to a large extent. In contrast, knowledge of cone-selective pathways in nonprimate dichromats is only slowly emerging, although retinas of dichromats like mice or rats are extensively studied as model systems for retinal information processing. Here, we review recent progress of research on color-coded pathways in nonprimate dichromats to identify differences or similarities between di- and trichromatic mammals. In addition, we applied immunohistochemical methods and confocal microscopy to retinas of different species and present data on their neuronal properties, which are expected to contribute to color vision. Basic neuronal features such as the “blue cone bipolar cell” exist in every species investigated so far. Moreover, there is increasing evidence for chromatic OFF channels in dichromats and retinal ganglion cells that relay color-opponent signals to the brain. In conclusion, di- and trichromats share similar retinal pathways for color transmission and processing.

BEHAVIORAL EVIDENCE FOR COLOR DISCRIMINATION IN CAT

1964 ◽  
Vol 27 (3) ◽  
pp. 323-333 ◽  
Author(s):  
Nancy K. Mello ◽  
Neil J. Peterson
Keyword(s):  
Color Discrimination ◽  
Behavioral Evidence

scholarly journals Sex-related differences in chromatic sensitivity

2008 ◽  
Vol 25 (3) ◽  
pp. 433-440 ◽  
Author(s):  
M. RODRÍGUEZ-CARMONA ◽  
L.T. SHARPE ◽  
J.A. HARLOW ◽  
J.L. BARBUR
Keyword(s):  
Color Vision ◽  
Color Space ◽  
Color Discrimination ◽  
Luminance Contrast ◽  
Choice Procedure ◽  
Significant Difference ◽  
Forced Choice Procedure ◽  
The Subject ◽  
Chromatic Sensitivity ◽  
Female Carriers

Generally women are believed to be more discriminating than men in the use of color names and this is often taken to imply superior color vision. However, if both X-chromosome linked color deficient males (∼8%) and females (<1%) as well as heterozygote female carriers (∼15%) are excluded from comparisons, then differences between men and women in red-green (RG) color discrimination have been reported as not being significant (e.g., Pickford, 1944; Hood et al., 2006). We re-examined this question by assessing the performance of 150 males and 150 females on the color assessment and diagnosis (CAD) test (Rodriguez-Carmona et al., 2005). This is a sensitive test that yields small color detection thresholds. The test employs direction-specific, moving, chromatic stimuli embedded in a background of random, dynamic, luminance contrast noise. A four-alternative, forced-choice procedure is employed to measure the subject's thresholds for detection of color signals in 16 directions in color space, while ensuring that the subject cannot make use of any residual luminance contrast signals. In addition, we measured the Rayleigh anomaloscope matches in a subgroup of 111 males and 114 females. All the age-matched males (30.8 ± 9.7) and females (26.7 ± 8.8) had normal color vision as diagnosed by a battery of conventional color vision tests. Females with known color deficient relatives were excluded from the study. Comparisons between the male and female groups revealed no significant differences in anomaloscope midpoints (p = 0.709), but a significant difference in matching ranges (p = 0.040); females on average tended to have a larger mean range (4.11) than males (3.75). Females also had significantly higher CAD thresholds than males along the RG (p = 0.0004), but not along the yellow-blue (YB) discrimination axis. The differences between males and females in RG discrimination may be related to the heterozygosity in X-linked cone photo pigment expression common among females.

scholarly journals Multidimensional scaling of D15 caps: Color-vision defects among tobacco smokers?

2004 ◽  
Vol 21 (3) ◽  
pp. 445-448 ◽  
Author(s):  
DAVID BIMLER ◽  
JOHN KIRKLAND
Keyword(s):  
Optic Nerve ◽  
Multidimensional Scaling ◽  
Color Vision ◽  
Color Space ◽  
Color Discrimination ◽  
Toxic Exposure ◽  
Panel Test ◽  
Individual Variations ◽  
Color Vision Defects ◽  
Vision Defects

Tobacco smoke contains a range of toxins including carbon monoxide and cyanide. With specialized cells and high metabolic demands, the optic nerve and retina are vulnerable to toxic exposure. We examined the possible effects of smoking on color vision: specifically, whether smokers perceive a different pattern of suprathreshold color dissimilarities from nonsmokers. It is already known that smokers differ in threshold color discrimination, with elevated scores on the Roth 28-Hue Desaturated panel test. Groups of smokers and nonsmokers, matched for sex and age, followed a triadic procedure to compare dissimilarities among 32 pigmented stimuli (the caps of the saturated and desaturated versions of the D15 panel test). Multidimensional scaling was applied to quantify individual variations in the salience of the axes of color space. Despite the briefness, simplicity, and “low-tech” nature of the procedure, subtle but statistically significant differences did emerge: on average the smoking group were significantly less sensitive to red–green differences. This is consistent with some form of injury to the optic nerve.

scholarly journals Comparison of color discrimination in chronic heavy smokers and healthy subjects

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 85 ◽  
Author(s):  
Thiago Monteiro de Paiva Fernandes ◽  
Natanael Antonio dos Santos
Keyword(s):  
Color Vision ◽  
Cigarette Smoke ◽  
Color Discrimination ◽  
Toxic Chemicals ◽  
Heavy Smoking ◽  
Gender And Education ◽  
Age Range ◽  
Fundoscopic Examination ◽  
Choice Method ◽  
Heavy Smokers

Background: Cigarette smoke is probably the most significant source of exposure to toxic chemicals for humans, involving health-damaging components, such as nicotine, hydrogen cyanide and formaldehyde. The aim of the present study was to assess the influence of chronic heavy smoking on color discrimination (CD). Methods: All subjects were free of any neuropsychiatric disorder, identifiable ocular disease and had normal acuity. No abnormalities were detected in the fundoscopic examination and in the optical coherence tomography exam. We assessed color vision for healthy heavy smokers (n = 15; age range, 20-45 years), deprived smokers (n = 15, age range 20-45 years) and healthy non-smokers (n = 15; age range, 20-45 years), using the psychophysical forced-choice method. All groups were matched for gender and education level. In this paradigm, the volunteers had to choose the pseudoisochromatic stimulus containing a test frequency at four directions (e.g., up, down, right and left) in the subtest of Cambridge Colour Test (CCT): Trivector. Results: Performance on CCT differed between groups, and the observed pattern was that smokers had lower discrimination compared to non-smokers. In addition, deprived smokers presented lower discrimination to smokers and non-smokers. Contrary to expectation, the largest differences were observed for medium and long wavelengths. Conclusions: These results suggests that cigarette smoke and chronic exposure to nicotine, or withdrawal from nicotine, affects CD. This highlights the importance of understanding the diffuse effects of nicotine either attentional bias on color vision.

scholarly journals Comparison of color discrimination in chronic heavy smokers and healthy subjects

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 85 ◽  
Author(s):  
Thiago Monteiro de Paiva Fernandes ◽  
Natalia Leandro Almeida ◽  
Natanael Antonio dos Santos
Keyword(s):  
Color Vision ◽  
Cigarette Smoke ◽  
Color Discrimination ◽  
Toxic Chemicals ◽  
Heavy Smoking ◽  
Gender And Education ◽  
Age Range ◽  
Fundoscopic Examination ◽  
Choice Method ◽  
Heavy Smokers

Background: Cigarette smoke is probably the most significant source of exposure to toxic chemicals for humans, involving health-damaging components, such as nicotine, hydrogen cyanide and formaldehyde. The aim of the present study was to assess the influence of chronic heavy smoking on color discrimination (CD). Methods: All subjects were free of any neuropsychiatric disorder, identifiable ocular disease and had normal acuity. No abnormalities were detected in the fundoscopic examination and in the optical coherence tomography exam. We assessed color vision for healthy heavy smokers (n = 15; age range, 20-45 years), deprived smokers (n = 15, age range 20-45 years) and healthy non-smokers (n = 15; age range, 20-45 years), using the psychophysical forced-choice method. All groups were matched for gender and education level. In this paradigm, the volunteers had to choose the pseudoisochromatic stimulus containing a test frequency at four directions (e.g., up, down, right and left) in the subtest of Cambridge Colour Test (CCT): Trivector. Results: Performance on CCT differed between groups, and the observed pattern was that smokers had lower discrimination compared to non-smokers. In addition, deprived smokers presented lower discrimination to smokers and non-smokers. Contrary to expectation, the largest differences were observed for medium and long wavelengths. Conclusions: These results suggests that cigarette smoke and chronic exposure to nicotine, or withdrawal from nicotine, affects CD. This highlights the importance of understanding the diffuse effects of nicotine either attentional bias on color vision.

Influences on Observers Color Discrimination with Normal Color Vision

2016 ◽  
Vol 36 (9) ◽  
pp. 0933001
Author(s):  
黄敏 Huang Min ◽  
史春洁 Shi Chunjie ◽  
李泽阳 Li Zeyang ◽  
刘浩学 Liu Haoxue
Keyword(s):  
Color Vision ◽  
Color Discrimination ◽  
Normal Color Vision

Color vision is strongly associated with retinal thinning in multiple sclerosis

2012 ◽  
Vol 18 (7) ◽  
pp. 991-999 ◽  
Author(s):  
Pablo Villoslada ◽  
Ami Cuneo ◽  
Jeffrey Gelfand ◽  
Stephen L Hauser ◽  
Ari Green
Keyword(s):  
Multiple Sclerosis ◽  
Visual Acuity ◽  
Color Vision ◽  
Color Discrimination ◽  
Visual Pathway ◽  
Visual Disability ◽  
Fiber Layer ◽  
Cross Sectional ◽  
Low Contrast ◽  
Sd Oct

Objectives: Multiple Sclerosis (MS) frequently causes injury to the anterior visual pathway (AVP), impairing quality of life due to visual dysfunction. Development of biomarkers in MS is a high priority and both low-contrast visual acuity (LCVA) and time-domain optical coherence tomography (TD-OCT) have been proposed as candidates for this purpose. We sought to assess whether psychophysical assessments of color vision are similarly correlated with structural measures of AVP injury, and therefore augment measures of visual disability in MS. Methods: We studied the association between high-contrast visual acuity (HCVA), LCVA, color vision (Hardy–Rand–Rittler plates (HRR) and Lanthony D15 tests) and OCT, using both high-resolution spectral-domain OCT (SD-OCT; Spectralis, Heidelberg Engineering, Germany) and TD-OCT (Stratus, Carl Zeiss, US) in a cohort of 213 MS patients (52 with previous optic neuritis) and 47 matched controls in a cross-sectional study. Results: We found that MS patients have impairments in HCVA and LCVA ( p < 0.001) but that they suffer from even more profound abnormalities in color discrimination ( p < 0.0001). We found strong correlation between color vision and SD-OCT measures of retinal nerve fiber layer (RNFL) thickness (average RNFL, r = 0.594, p < 0.001) and papillomacular bundle thickness ( r = −0.565, p < 0.001). The correlation between OCT scores and functional visual impairments of all types was much stronger for SD-OCT than for TD-OCT. Conclusion: Our results indicate that color vision is highly correlated with these OCT scores when compared with traditional measures of visual acuity. Also we found that SD-OCT is superior to TD-OCT for detecting anterior visual pathway damage in MS. This makes both color-visual measures and SD-OCT strong candidate biomarkers of disease progression.

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