The visual pigments and oil droplets of the chicken retina

Bowmaker, James K.; Knowles, Aubrey

doi:10.1016/0042-6989(77)90117-1

Cited by 182 publications

(103 citation statements)

References 15 publications

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“…These spectra are similar to those obtained for the chicken by Bowmaker and Knowles (Bowmaker and Knowles, 1977) and Bowmaker et al (Bowmaker et al, 1997), although there are distinct differences in the absorption spectra of specific droplet types depending on retinal location and light-treatment group. These differences are also evident in Fig.·3, in which mean oil droplet cut-off wavelength (l cut ) is plotted against weeks of treatment for both bright-light and dim-light groups.…”

Section: Microspectrophotometrysupporting

confidence: 73%

“…Cone outer segment absorptance was modelled using the rhodopsin (vitamin A 1 -based) visual pigment templates of Govardovskii et al (Govardovskii et al, 2000), a specific (decadic) absorbance of 0.014·mm -1 (Bowmaker and Knowles, 1977) and a cone outer segment length of 16·mm (Morris and Shorey, 1967). Microspectrophotometrically measured oil droplet absorptance spectra recorded from the last chicken sampled (after 29·weeks of light treatment, i.e.…”

Section: Modelling the Spectral Sensitivity Of Cone Outer Segmentsmentioning

confidence: 99%

“…For example, in the case of avian MWS and LWS single cones, calculations show that absorption of short wavelengths by the Y-and R-type oil droplets will shift the wavelength of peak sensitivity of the cones approximately 40·nm towards longer wavelengths (540·nm and 605·nm, respectively) and reduce the sensitivity of the outer segment by 50% or more (Bowmaker and Knowles, 1977;Hart and Vorobyev, 2005). For all cone types, the absorption of short wavelengths by the pigmented oil droplets narrows the spectral sensitivity function of the photoreceptor and reduces the overlap between adjacent spectral classes, potentially improving the discrimination of broadband (i.e.…”

Section: Introductionmentioning

confidence: 99%

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Cone photoreceptor oil droplet pigmentation is affected by ambient light intensity

Hart

Lisney

Collin

2006

Journal of Experimental Biology

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SUMMARY The cone photoreceptors of many vertebrates contain spherical organelles called oil droplets. In birds, turtles, lizards and some lungfish the oil droplets are heavily pigmented and function to filter the spectrum of light incident upon the visual pigment within the outer segment. Pigmented oil droplets are beneficial for colour discrimination in bright light, but at lower light levels the reduction in sensitivity caused by the pigmentation increasingly outweighs the benefits generated by spectral tuning. Consequently, it is expected that species with pigmented oil droplets should modulate the density of pigment in response to ambient light intensity and thereby regulate the amount of light transmitted to the outer segment. In this study, microspectrophotometry was used to measure the absorption spectra of cone oil droplets in chickens (Gallus gallus domesticus) reared under bright (unfiltered) or dim (filtered) sunlight. Oil droplet pigmentation was found to be dependent on the intensity of the ambient light and the duration of exposure to the different lighting treatments. In adult chickens reared in bright light, the oil droplets of all cone types (except the violet-sensitive single cones, whose oil droplet is always non-pigmented) were more densely pigmented than those in chickens reared in dim light. Calculations show that the reduced levels of oil droplet pigmentation in chickens reared in dim light would increase the sensitivity and spectral bandwidth of the outer segment significantly. The density of pigmentation in the oil droplets presumably represents a trade-off between the need for good colour discrimination and absolute sensitivity. This might also explain why nocturnal animals, or those that underwent a nocturnal phase during their evolution, have evolved oil droplets with low pigment densities or no pigmentation or have lost their oil droplets altogether.

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Section: Microspectrophotometrysupporting

confidence: 73%

Section: Modelling the Spectral Sensitivity Of Cone Outer Segmentsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Cone photoreceptor oil droplet pigmentation is affected by ambient light intensity

Hart

Lisney

Collin

2006

Journal of Experimental Biology

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“…The A1 pigment with a chicken RH2 opsin has a l max of 508 nm (Okano et al, 1992). Having a green oil-droplet, however, the chicken cone with the RH2 pigments actually has a l max of 533 nm (Bowmaker and Knowles, 1977).…”

Section: Red-green Color Visionmentioning

confidence: 99%

Molecular evolution of color vision in vertebrates

Yokoyama

2002

Gene

261

231

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Visual systems of vertebrates exhibit a striking level of diversity, reflecting their adaptive responses to various color environments. The photosensitive molecules, visual pigments, can be synthesized in vitro and their absorption spectra can be determined. Comparing the amino acid sequences and absorption spectra of various visual pigments, we can identify amino acid changes that have modified the absorption spectra of visual pigments. These hypotheses can then be tested using the in vitro assay. This approach has been a powerful tool in elucidating not only the molecular bases of color vision, but the processes of adaptive evolution at the molecular level. q

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“…Both retinal and extra-retinal photoreceptors are responsive to red light, which stimulates gonadal development (Woodardet et al 1969;Pyrzaket et al 1987). Retinal cone cells contain coloured oil droplets that filter light and pass the signal to photoreactive pigments (Bowmaker and Knowles 1977). These cone cells respond maximally to violet, blue, green, and yellow spectrum (Dartnall et al 1983).…”

Section: Introductionmentioning

confidence: 99%

Effect of light colour on egg production and egg contamination

Svobodová¹,

Tůmová²,

Popelářová³

et al. 2015

CZECH J ANIM SCI

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ABSTRACT:The objective of this study was to compare the performance of laying hens, quality of air in poultry house, and microbial contamination of eggshell in laying hens kept under blue, green, red, and yellow light colour in enriched cages. The daily photoperiod consisted of 15 h light, light intensity of 10 lx at bird head level. The laying performance characteristics (hen-day egg production, mortality, and egg weight) were not affected by light colour. Similarly, microbial contamination of the air was not significantly different related to the light colour. There were significant interactions in eggshell contamination between the position of the cage floor and light colour in Escherichia coli (P ≤ 0.042) and Enterococcus (P ≤ 0.019). The highest number of Escherichia coli was detected in eggs from hens housed on the middle floor given yellow light (6.06 log colony forming units (cfu)/eggshell) and the lowest values (3.30 log cfu/eggshell) on the upper floor also under yellow light colour. Similar results were observed in Enterococcus, where the highest contamination was on the middle floor under yellow light colour (5.26 log cfu/eggshell), while the lowest contamination (2.45 log cfu/eggshell) was found on the upper floor under blue colour. The results of our study indicate that the light colour has a minor effect on microbial contamination but the significant influence was in the floor position. The highest microbial egg contamination was found on eggs from the middle floor.

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The visual pigments and oil droplets of the chicken retina

Cited by 182 publications

References 15 publications

Cone photoreceptor oil droplet pigmentation is affected by ambient light intensity

Cone photoreceptor oil droplet pigmentation is affected by ambient light intensity

Molecular evolution of color vision in vertebrates

Effect of light colour on egg production and egg contamination

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