scholarly journals A role of color vision in emmetropization in C57BL/6J mice

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jinglei Yang ◽  
Li Yang ◽  
Rongfang Chen ◽  
Yun Zhu ◽  
Siyao Wang ◽  
...  
Keyword(s):  
Color Vision ◽  
White Light ◽  
Fluorescent Protein ◽  
Red Light ◽  
Spectral Composition ◽  
Chromatic Aberration ◽  
Corneal Curvature ◽  
Red Fluorescent Protein ◽  
Reporter Mice ◽  
Eye Opening

Abstract Spectral composition affects emmetropization in both humans and animal models. Because color vision interacts the effects of chromatic defocus, we developed a method to bypass the effects of longitudinal chromatic aberration by placing a spectral filter behind the optics of the eye, using genetic tools. Newborn C57BL/6J (B6) mice were reared in quasi-monochromatic red (410–510 nm) or blue (585–660 nm) light beginning before eye-opening. Refractive states and ocular dimensions were compared at 4, 6, 8, and 10 weeks with mice reared in normal white light. Cre recombinase-dependent Ai9 reporter mice were crossed with Chx10-Cre to obtain Chx10-Cre;Ai9 mice, expressing red fluorescent protein in retinal Cre-positive cells. Ai9 offsprings, with and without Cre, were reared under a normal visual environment. Refraction and axial components were measured as described above. Expression levels of M and S opsin were quantified by western blotting at 10 weeks. Compared with those reared in white light, B6 mice reared in red light developed relative hyperopia, principally characterized by flattening of corneal curvature. Emmetropization was not affected by blue light, possibly because the reduction in vitreous chamber depth compensated for the increase in corneal curvature. Compared with Cre-negative littermates, the refraction and axial dimensions of Chx10-Cre;Ai9 mice were not significantly different at the follow-up timepoints. M opsin levels were higher in Chx10-Cre;Ai9 mice at 10 weeks while S opsin levels were not different. Red light induced a hyperopic shift in mouse refractive development. Emmetropization was not impacted in mice with perturbed color vision caused by intrinsic red-fluorescent protein, suggesting that color vision may not be necessary in mouse emmetropization when other mechanisms are present.

scholarly journals The Preferences of Different Cultivars of Lettuce Seedlings (Lactuca sativa L.) for the Spectral Composition of Light

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1211
Author(s):  
Barbara Frąszczak ◽  
Monika Kula-Maximenko
Keyword(s):  
Chlorophyll Content ◽  
Blue Light ◽  
White Light ◽  
Leaf Shape ◽  
Red Light ◽  
Spectral Composition ◽  
Fresh Weight ◽  
Light Spectrum ◽  
Dark Green ◽  
Relative Chlorophyll Content

The spectrum of light significantly influences the growth of plants cultivated in closed systems. Five lettuce cultivars with different leaf colours were grown under white light (W, 170 μmol m−2 s−1) and under white light with the addition of red (W + R) or blue light (W + B) (230 μmol m−2 s−1). The plants were grown until they reached the seedling phase (30 days). Each cultivar reacted differently to the light spectrum applied. The red-leaved cultivar exhibited the strongest plasticity in response to the spectrum. The blue light stimulated the growth of the leaf surface in all the plants. The red light negatively influenced the length of leaves in the cultivars, but it positively affected their number in red and dark-green lettuce. It also increased the relative chlorophyll content and fresh weight gain in the cultivars containing anthocyanins. When the cultivars were grown under white light, they had longer leaves and higher value of the leaf shape index. The light-green cultivars had a greater fresh weight. Both the addition of blue and red light significantly increased the relative chlorophyll content in the dark-green cultivar. The spectrum enhanced with blue light had positive influence on most of the parameters under analysis in butter lettuce cultivars. These cultivars were also characterised by the highest absorbance of blue light.

scholarly journals Acclimatization of symbiotic corals to mesophotic light environments through wavelength transformation by fluorescent protein pigments

2017 ◽  
Vol 284 (1858) ◽  
pp. 20170320 ◽  
Author(s):  
Edward G. Smith ◽  
Cecilia D'Angelo ◽  
Yoni Sharon ◽  
Dan Tchernov ◽  
Joerg Wiedenmann
Keyword(s):  
Fluorescent Protein ◽  
Fluorescent Proteins ◽  
Environmental Gradients ◽  
Red Light ◽  
Spectral Composition ◽  
Light Environment ◽  
Homogeneous Distribution ◽  
Red Fluorescent Proteins ◽  
Ecological Importance ◽  
Colour Morphs

The depth distribution of reef-building corals exposes their photosynthetic symbionts of the genus Symbiodinium to extreme gradients in the intensity and spectral quality of the ambient light environment. Characterizing the mechanisms used by the coral holobiont to respond to the low intensity and reduced spectral composition of the light environment in deeper reefs (greater than 20 m) is fundamental to our understanding of the functioning and structure of reefs across depth gradients. Here, we demonstrate that host pigments, specifically photoconvertible red fluorescent proteins (pcRFPs), can promote coral adaptation/acclimatization to deeper-water light environments by transforming the prevalent blue light into orange-red light, which can penetrate deeper within zooxanthellae-containing tissues; this facilitates a more homogeneous distribution of photons across symbiont communities. The ecological importance of pcRFPs in deeper reefs is supported by the increasing proportion of red fluorescent corals with depth (measured down to 45 m) and increased survival of colour morphs with strong expression of pcRFPs in long-term light manipulation experiments. In addition to screening by host pigments from high light intensities in shallow water, the spectral transformation observed in deeper-water corals highlights the importance of GFP-like protein expression as an ecological mechanism to support the functioning of the coral– Symbiodinium association across steep environmental gradients.

scholarly journals Effects of achromatic and chromatic lights on pupillary response, endocrinology, activity, and milk production in dairy cows

PLoS ONE ◽  
2021 ◽  
Vol 16 (7) ◽  
pp. e0253776
Author(s):  
Sofia Lindkvist ◽  
Emma Ternman ◽  
Sabine Ferneborg ◽  
Daniel Bånkestad ◽  
Johan Lindqvist ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Blue Light ◽  
Milk Production ◽  
Milk Yield ◽  
White Light ◽  
Pupil Size ◽  
Red Light ◽  
Spectral Composition ◽  
Management Tool ◽  
Lactating Cows

Artificial light can be used as a management tool to increase milk yield in dairy production. However, little is known about how cows respond to the spectral composition of light. The aim of this study was to investigate how dairy cows respond to artificial achromatic and chromatic lights. A tie-stall barn equipped with light-emitting diode (LED) light fixtures was used to create the controlled experimental light environments. Two experiments were conducted, both using dairy cows of Swedish Red and light mixtures with red, blue or white light. In experiment I, the response to light of increasing intensity on pupil size was evaluated in five pregnant non-lactating cows. In experiment II 16h of achromatic and chromatic daylight in combination with dim, achromatic night light, was tested on pregnant lactating cows during five weeks to observe long term effects on milk production, activity and circadian rhythms. Particular focus was given to possible carry over effects of blue light during the day on activity at night since this has been demonstrated in humans. Increasing intensity of white and blue light affected pupil size (P<0.001), but there was no effect on pupil size with increased intensity of red light. Milk yield was maintained throughout experiment II, and plasma melatonin was higher during dim night light than in daylight for all treatments (P<0.001). In conclusion, our results show that LED fixtures emitting red light driving the ipRGCs indirectly via ML-cones, blue light stimulating both S-cones and ipRGCs directly and a mixture of wavelengths (white light) exert similar effects on milk yield and activity in tied-up dairy cows. This suggests that the spectral composition of LED lighting in a barn is secondary to duration and intensity.

scholarly journals Faithful activation of an extra-bright red fluorescent protein in “knock-in” Cre-reporter mice ideally suited for lineage tracing studies

2007 ◽  
Vol 37 (1) ◽  
pp. 43-53 ◽  
Author(s):  
Hervé Luche ◽  
Odile Weber ◽  
Tata Nageswara Rao ◽  
Carmen Blum ◽  
Hans Jörg Fehling
Keyword(s):  
Fluorescent Protein ◽  
Lineage Tracing ◽  
Red Fluorescent Protein ◽  
Reporter Mice

scholarly journals The axial chromatic aberration of the human eye

1914 ◽  
Vol 90 (620) ◽  
pp. 440-443 ◽  
Keyword(s):  
White Light ◽  
Red Light ◽  
Monochromatic Light ◽  
Chromatic Aberration ◽  
The Other ◽  
Small Hole ◽  
Human Eye ◽  
Bright Object ◽  
Normal Human ◽  
Extreme Rays

A bright object viewed directly by a normal human eye shows no perceptible coloourd fringes. From this it has been assumed by some that the eye is fairly well corrected chromatically, at least for the most luminous constituents of white light. On the other hand, if the same object be viewed through a filter transmitting only the extreme red and blue, it will appear with either a red or blue fringe, showing that for these extreme rays the eye is not corrected. Helmholtz passed monochromatic light through a small hole and found that when red light was used, the hole appeared in best focus when viewed from a distance of about 8 feet. With blue illumination it appeared brightest at about 1 1/2 feet, and with extreme violet but a few inches (nur einige Zolle). With these rough determinations of Helmholtz the question appears to have rested.

Fluorescent proteins for in vivo imaging, where's the biliverdin?

2020 ◽  
Vol 48 (6) ◽  
pp. 2657-2667
Author(s):  
Felipe Montecinos-Franjola ◽  
John Y. Lin ◽  
Erik A. Rodriguez
Keyword(s):  
Hydrogen Peroxide ◽  
In Vivo Imaging ◽  
Near Infrared ◽  
Fluorescent Protein ◽  
Fluorescent Proteins ◽  
Fluorescent Imaging ◽  
Infrared Light ◽  
Red Fluorescent Protein ◽  
Color Palette

Noninvasive fluorescent imaging requires far-red and near-infrared fluorescent proteins for deeper imaging. Near-infrared light penetrates biological tissue with blood vessels due to low absorbance, scattering, and reflection of light and has a greater signal-to-noise due to less autofluorescence. Far-red and near-infrared fluorescent proteins absorb light &gt;600 nm to expand the color palette for imaging multiple biosensors and noninvasive in vivo imaging. The ideal fluorescent proteins are bright, photobleach minimally, express well in the desired cells, do not oligomerize, and generate or incorporate exogenous fluorophores efficiently. Coral-derived red fluorescent proteins require oxygen for fluorophore formation and release two hydrogen peroxide molecules. New fluorescent proteins based on phytochrome and phycobiliproteins use biliverdin IXα as fluorophores, do not require oxygen for maturation to image anaerobic organisms and tumor core, and do not generate hydrogen peroxide. The small Ultra-Red Fluorescent Protein (smURFP) was evolved from a cyanobacterial phycobiliprotein to covalently attach biliverdin as an exogenous fluorophore. The small Ultra-Red Fluorescent Protein is biophysically as bright as the enhanced green fluorescent protein, is exceptionally photostable, used for biosensor development, and visible in living mice. Novel applications of smURFP include in vitro protein diagnostics with attomolar (10−18 M) sensitivity, encapsulation in viral particles, and fluorescent protein nanoparticles. However, the availability of biliverdin limits the fluorescence of biliverdin-attaching fluorescent proteins; hence, extra biliverdin is needed to enhance brightness. New methods for improved biliverdin bioavailability are necessary to develop improved bright far-red and near-infrared fluorescent proteins for noninvasive imaging in vivo.

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