Expression patterns of cryptochrome genes in avian retina suggest involvement of Cry4 in light-dependent magnetoreception

Journal of The Royal Society Interface, Journal Year: 2018, Volume and Issue: 15(140), P. 20180058 - 20180058

Published: March 1, 2018

The light-dependent magnetic compass of birds provides orientation information about the spatial alignment geomagnetic field. It is proposed to be located in avian retina, and mediated by a light-induced, biochemical radical-pair mechanism involving cryptochromes as putative receptor molecules. At same time, are known for their role negative feedback loop circadian clock. We measured gene expression Cry1, Cry2 Cry4 muscle brain zebra finches over day assess whether they showed any rhythmicity. hypothesized that retinal involved magnetoreception should expressed at constant level day, because use not only during migration, but also tasks daily life. Cryptochromes serving tasks, on other hand, expected rhythmic (circadian) pattern. Cry1 displayed variation retina clock genes, while levels time. conclude most likely candidate magnetoreceptor birds.

Language: Английский

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Quantum effects in the brain: A review

AVS Quantum Science, Journal Year: 2020, Volume and Issue: 2(2)

Published: April 1, 2020

In the mid-1990s, it was proposed that quantum effects in proteins known as microtubules play a role nature of consciousness. The theory largely dismissed due to fact were thought unlikely occur biological systems, which are warm and wet subject decoherence. However, development biology now suggests otherwise. Quantum have been implicated photosynthesis, process fundamental life on earth. They also possibly at other processes such avian migration olfaction. microtubule mechanism consciousness has joined by theories cognition. It general anesthetic, switches off consciousness, does this through means, measured changes electron spin. tunneling hypothesis developed context olfaction applied action neurotransmitters. A recent outlines how entanglement between phosphorus nuclei might influence firing neurons. These, theories, contributed growing field research investigates whether contribute neural processing. This review aims investigate current state fully is supported convincing experimental evidence. clarify sites these progress made wider be relevant specific case brain.

Language: Английский

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Bird colour vision – from cones to perception

Current Opinion in Behavioral Sciences, Journal Year: 2019, Volume and Issue: 30, P. 34 - 40

Published: July 4, 2019

Language: Английский

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The Magnetic Compass of Birds: The Role of Cryptochrome

Frontiers in Physiology, Journal Year: 2021, Volume and Issue: 12

Published: May 19, 2021

The geomagnetic field provides directional information for birds. avian magnetic compass is an inclination that uses not the polarity of but axial course lines and their in space. It works a flexible functional window, it requires short-wavelength light. These characteristics result from underlying sensory mechanism based on radical pair processes eyes, with cryptochrome suggested as receptor molecule. chromophore cryptochrome, flavin adenine dinucleotide (FAD), undergoes photocycle, where pairs are formed during photo-reduction well re-oxidation; behavioral data indicate latter crucial detecting directions. Five types cryptochromes found retina birds: 1a (Cry1a), 1b, 2, 4a, 4b. Because its location outer segments ultraviolet cones clear oil droplets, Cry1a appears to be most likely molecule information.

Language: Английский

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Protein-protein interaction of the putative magnetoreceptor cryptochrome 4 expressed in the avian retina

Scientific Reports, Journal Year: 2020, Volume and Issue: 10(1)

Published: April 30, 2020

Abstract Migratory birds can sense the Earth’s magnetic field and use it for orientation over thousands of kilometres. A light-dependent radical-pair mechanism associated with visual system is currently discussed as underlying compass sense. The blue light receptor cryptochrome 4 (Cry4) considered most likely primary sensory protein that detects geomagnetic field. Since interaction partners Cry4 are completely unknown at present, here, we aim to identify potential candidate in avian retina. We used yeast-two-hybrid screen cDNA libraries possible European robin. UAS-GAL yeast two hybrid was applied confirm a group partners. Six proteins were found be particularly promising candidates interacting robin Cry4. identified genes code guanine nucleotide-binding G(t) subunit alpha-2 (GNAT2), long-wavelength-sensitive opsin (LWS, also called iodopsin), gamma 10 (GNG10), potassium voltage-gated channel subfamily V member 2 (KCNV2), retinol binding 1 (RBP1) retinal G protein-coupled (RGR). All known expressed vertebrate retinae different species. conclude by discussing putative signalling pathways could connect one or more these 6 candidates.

Language: Английский

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Cryptochrome magnetoreception: four tryptophans could be better than three

Journal of The Royal Society Interface, Journal Year: 2021, Volume and Issue: 18(184)

Published: Nov. 1, 2021

The biophysical mechanism of the magnetic compass sensor in migratory songbirds is thought to involve photo-induced radical pairs formed cryptochrome (Cry) flavoproteins located photoreceptor cells eyes. In Cry4a—the most likely six known avian Crys have a sensing function—four pair states are sequentially by stepwise transfer an electron along chain four tryptophan residues photo-excited flavin. purified Cry4a from European robin, third these flavin–tryptophan more magnetically sensitive than fourth, consistent with smaller separation radicals former. Here, we explore idea that two could exist rapid dynamic equilibrium such key and kinetic properties weighted averages. Spin dynamics simulations suggest largely responsible for while fourth may be better placed initiate signalling particularly if terminal can reduced nearby tyrosine. Such arrangement allowed independent optimization essential functions protein. It might also rationalize why has tryptophans plants only three.

Language: Английский

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Broadband 75–85 MHz radiofrequency fields disrupt magnetic compass orientation in night-migratory songbirds consistent with a flavin-based radical pair magnetoreceptor

Journal of Comparative Physiology A, Journal Year: 2022, Volume and Issue: 208(1), P. 97 - 106

Published: Jan. 1, 2022

The light-dependent magnetic compass sense of night-migratory songbirds can be disrupted by weak radiofrequency fields. This finding supports a quantum mechanical, radical-pair-based mechanism magnetoreception as observed for isolated cryptochrome 4, protein found in birds' retinas. exact identity the magnetically sensitive radicals is uncertain vivo, but their formation seems to require bound flavin adenine dinucleotide chromophore and chain four tryptophan residues within protein. Resulting from hyperfine interactions nuclear spins with unpaired electrons, sensitivity fields depends strongly on number nuclei (hydrogen nitrogen atoms) they contain. Quantum-chemical calculations suggested that electromagnetic noise frequency range 75-85 MHz could give information about involved. Here, we show broadband prevent songbird using its behavioural experiments. These results indicate at least one components radical pair involved sensory process avian must contain substantial strong would case if flavin-tryptophan were sensor.

Language: Английский

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Double cones in the avian retina form an oriented mosaic which might facilitate magnetoreception and/or polarized light sensing

Journal of The Royal Society Interface, Journal Year: 2022, Volume and Issue: 19(189)

Published: April 1, 2022

To navigate between breeding and wintering grounds, night-migratory songbirds are aided by a light-dependent magnetic compass sense maybe also polarized light vision. Although the underlying mechanisms for magnetoreception sensing remain unclear, double cone photoreceptors in avian retina have been suggested to represent primary sensory cells. use these senses, birds must be able separate directional information from Earth's field and/or polarization variations intensity. Theoretical considerations suggest that this could best achieved if neighbouring cones were oriented an ordered pattern. Therefore, we investigate orientation patterns of European robins ( Erithacus rubecula ) domestic chickens Gallus gallus domesticus ). We used whole-mounted retinas labelled with markers quantify orientations individual relation their nearest neighbours. In both species, our data show array is highly ordered: angles more likely 90°/−90° central 180°/0° peripheral retina, respectively. The observed regularity aid cells' putative function sensing.

Language: Английский

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Upper bound for broadband radiofrequency field disruption of magnetic compass orientation in night-migratory songbirds

Proceedings of the National Academy of Sciences, Journal Year: 2023, Volume and Issue: 120(28)

Published: July 3, 2023

Night-migratory songbirds have a light-dependent magnetic compass sense, the mechanism of which is thought to depend on photochemical formation radical pairs in cryptochrome (Cry) proteins located retina. The finding that weak radiofrequency (RF) electromagnetic fields can prevent birds from orienting Earth's field has been regarded as diagnostic test for this and potential source information identities radicals. maximum frequency could cause such disorientation predicted lie between 120 220 MHz flavin-tryptophan pair Cry. Here we show orientation capabilities Eurasian blackcaps (Sylvia atricapilla) are not affected by RF noise bands 140 150 235 245 MHz. From consideration its internal interactions, argue effects flavin-containing radical-pair sensor should be approximately independent up 116 birds' sensitivity fall about two orders magnitude when exceeds Taken together with our earlier 75 85 disrupt blackcaps, these results provide compelling evidence migratory operates mechanism.

Language: Английский

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Tracking the Electron Transfer Cascade in European Robin Cryptochrome 4 Mutants

Journal of the American Chemical Society, Journal Year: 2023, Volume and Issue: 145(21), P. 11566 - 11578

Published: May 17, 2023

The primary step in the elusive ability of migratory birds to sense weak Earth-strength magnetic fields is supposedly light-induced formation a long-lived, magnetically sensitive radical pair inside cryptochrome flavoprotein located retina these birds. Blue light absorption by flavin chromophore triggers series sequential electron transfer steps across tetradic tryptophan chain towards acceptor. recent express 4 from night-migratory European robin (Erithacus rubecula), ErCry4, and replace residues individually redox-inactive phenylalanine offers prospect exploring role each chain. Here, we compare ultrafast transient spectroscopy wild type ErCry4 four its mutants having different positions In observe that first three adds distinct relaxation component (time constants 0.5, 30 150 ps) data. dynamics mutant with terminal residue are very similar those excepted for reduced concentration long-lived pairs. experimental results evaluated discussed connection Marcus-Hopfield theory, providing complete microscopic insight into transfers Our offer path studying spin transport dynamical correlations

Language: Английский

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