1
|
Karwinkel T, Peter A, Holland RA, Thorup K, Bairlein F, Schmaljohann H. A conceptual framework on the role of magnetic cues in songbird migration ecology. Biol Rev Camb Philos Soc 2024; 99:1576-1593. [PMID: 38629349 DOI: 10.1111/brv.13082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 03/27/2024] [Accepted: 03/29/2024] [Indexed: 07/06/2024]
Abstract
Migrating animals perform astonishing seasonal movements by orienting and navigating over thousands of kilometres with great precision. Many migratory species use cues from the sun, stars, landmarks, olfaction and the Earth's magnetic field for this task. Among vertebrates, songbirds are the most studied taxon in magnetic-cue-related research. Despite multiple studies, we still lack a clear understanding of when, where and how magnetic cues affect the decision-making process of birds and hence, their realised migratory behaviour in the wild. This understanding is especially important to interpret the results of laboratory experiments in an ecologically appropriate way. In this review, we summarise the current findings about the role of magnetic cues for migratory decisions in songbirds. First, we review the methodological principles for orientation and navigation research, specifically by comparing experiments on caged birds with experiments on free-flying birds. While cage experiments can show the sensory abilities of birds, studies with free-flying birds can characterise the ecological roles of magnetic cues. Second, we review the migratory stages, from stopover to endurance flight, in which songbirds use magnetic cues for their migratory decisions and incorporate this into a novel conceptual framework. While we lack studies examining whether and when magnetic cues affect orientation or navigation decisions during flight, the role of magnetic cues during stopover is relatively well studied, but mostly in the laboratory. Notably, many such studies have produced contradictory results so that understanding the biological importance of magnetic cues for decisions in free-flying songbirds is not straightforward. One potential explanation is that reproducibility of magnetic-cue experiments is low, probably because variability in the behavioural responses of birds among experiments is high. We are convinced that parts of this variability can be explained by species-specific and context-dependent reactions of birds to the study conditions and by the bird's high flexibility in whether they include magnetic cues in a decision or not. Ultimately, this review should help researchers in the challenging field of magnetoreception to design experiments meticulously and interpret results of such studies carefully by considering the migration ecology of their focal species.
Collapse
Affiliation(s)
- Thiemo Karwinkel
- Institute of Avian Research 'Vogelwarte Helgoland', An der Vogelwarte 21, 26386, Wilhelmshaven, Germany
- Carl von Ossietzky Universität Oldenburg, School of Mathematics and Science, Institute of Biology and Environmental Sciences, Ammerländer Heerstraße 114-118, 26129, Oldenburg, Germany
| | - Annika Peter
- Carl von Ossietzky Universität Oldenburg, School of Mathematics and Science, Institute of Biology and Environmental Sciences, Ammerländer Heerstraße 114-118, 26129, Oldenburg, Germany
| | - Richard A Holland
- School of Environmental and Natural Sciences, Bangor University, Bangor, LL57 2UW, UK
| | - Kasper Thorup
- Center for Macroecology, Evolution and Climate, Natural History Museum of Denmark, University of Copenhagen, Universitetsparken 15, DK-2100, Copenhagen, Denmark
| | - Franz Bairlein
- Institute of Avian Research 'Vogelwarte Helgoland', An der Vogelwarte 21, 26386, Wilhelmshaven, Germany
- Max Planck Institute of Animal Behavior, Am Obstberg 1, Radolfzell, 78315, Germany
| | - Heiko Schmaljohann
- Institute of Avian Research 'Vogelwarte Helgoland', An der Vogelwarte 21, 26386, Wilhelmshaven, Germany
- Carl von Ossietzky Universität Oldenburg, School of Mathematics and Science, Institute of Biology and Environmental Sciences, Ammerländer Heerstraße 114-118, 26129, Oldenburg, Germany
| |
Collapse
|
2
|
Golesworthy MJ, Zollitsch T, Luo J, Selby D, Jarocha LE, Henbest KB, Paré-Labrosse O, Bartölke R, Schmidt J, Xu J, Mouritsen H, Hore PJ, Timmel CR, Mackenzie SR. Singlet-triplet dephasing in radical pairs in avian cryptochromes leads to time-dependent magnetic field effects. J Chem Phys 2023; 159:105102. [PMID: 37694754 DOI: 10.1063/5.0166675] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 08/21/2023] [Indexed: 09/12/2023] Open
Abstract
Cryptochrome 4a (Cry4a) has been proposed as the sensor at the heart of the magnetic compass in migratory songbirds. Blue-light excitation of this protein produces magnetically sensitive flavin-tryptophan radical pairs whose properties suggest that Cry4a could indeed be suitable as a magnetoreceptor. Here, we use cavity ring-down spectroscopy to measure magnetic field effects on the kinetics of these radical pairs in modified Cry4a proteins from the migratory European robin and from nonmigratory pigeon and chicken. B1/2, a parameter that characterizes the magnetic field-dependence of the reactions, was found to be larger than expected on the basis of hyperfine interactions and to increase with the delay between pump and probe laser pulses. Semiclassical spin dynamics simulations show that this behavior is consistent with a singlet-triplet dephasing (STD) relaxation mechanism. Analysis of the experimental data gives dephasing rate constants, rSTD, in the range 3-6 × 107 s-1. A simple "toy" model due to Maeda, Miura, and Arai [Mol. Phys. 104, 1779-1788 (2006)] is used to shed light on the origin of the time-dependence and the nature of the STD mechanism. Under the conditions of the experiments, STD results in an exponential approach to spin equilibrium at a rate considerably slower than rSTD. We attribute the loss of singlet-triplet coherence to electron hopping between the second and third tryptophans of the electron transfer chain and comment on whether this process could explain differences in the magnetic sensitivity of robin, chicken, and pigeon Cry4a's.
Collapse
Affiliation(s)
| | - Tilo Zollitsch
- Department of Chemistry, University of Oxford, Oxford, United Kingdom
| | - Jiate Luo
- Department of Chemistry, University of Oxford, Oxford, United Kingdom
| | - Dan Selby
- Department of Chemistry, University of Oxford, Oxford, United Kingdom
| | - Lauren E Jarocha
- Department of Chemistry, University of Oxford, Oxford, United Kingdom
- Department of Chemistry, Furman University, Greenville, South Carolina 29613, USA
| | - Kevin B Henbest
- Department of Chemistry, University of Oxford, Oxford, United Kingdom
| | | | - Rabea Bartölke
- AG Neurosensory Sciences/Animal Navigation, Institut für Biologie und Umweltwissenschaften, Carl-von-Ossietzky Universität Oldenburg, Oldenburg, Germany
| | - Jessica Schmidt
- AG Neurosensory Sciences/Animal Navigation, Institut für Biologie und Umweltwissenschaften, Carl-von-Ossietzky Universität Oldenburg, Oldenburg, Germany
| | - Jingjing Xu
- AG Neurosensory Sciences/Animal Navigation, Institut für Biologie und Umweltwissenschaften, Carl-von-Ossietzky Universität Oldenburg, Oldenburg, Germany
| | - Henrik Mouritsen
- AG Neurosensory Sciences/Animal Navigation, Institut für Biologie und Umweltwissenschaften, Carl-von-Ossietzky Universität Oldenburg, Oldenburg, Germany
- Research Centre for Neurosensory Sciences, University of Oldenburg, Oldenburg, Germany
| | - P J Hore
- Department of Chemistry, University of Oxford, Oxford, United Kingdom
| | | | | |
Collapse
|
3
|
Wynn J, Leberecht B, Liedvogel M, Burnus L, Chetverikova R, Döge S, Karwinkel T, Kobylkov D, Xu J, Mouritsen H. Naive songbirds show seasonally appropriate spring orientation in the laboratory despite having never completed first migration. Biol Lett 2023; 19:20220478. [PMCID: PMC9943868 DOI: 10.1098/rsbl.2022.0478] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023] Open
Abstract
The role of inherited orientation programmes in determining the outbound migratory routes of birds is increasingly well understood, though less is known about the influence of inherited information on return migration. Previous studies suggest that spatial gradient cues learnt through experience could be of considerable importance when relocating the natal site, though such cues could, in principle, augment rather than replace inherited migratory information. Here, we show that juvenile Eurasian blackcaps (Sylvia atricapilla) that have never left northwest Europe (i.e. never had the opportunity to learn navigational information on a continental scale) show significant spring orientation in a direction near-identical to that expected based on ringing recoveries from free-flying individuals. We suggest that this is probably indicative of birds inheriting an orientation programme for spring as well as autumn migration and speculate that, as long as the birds are not displaced far from their normal migration route, the use of inherited spring migratory trajectories might make uni-coordinate ‘stop signs’ sufficiently accurate for the long-distance targeting of their breeding sites.
Collapse
Affiliation(s)
- Joe Wynn
- Institut für Vogelforschung “Vogelwarte Helgoland”, An Der Vogelwarte 21, 26386, Wilhelmshaven, Germany
| | - Bo Leberecht
- AG ‘Neurosensorik/Animal Navigation’, Carl-von-Ossietzky Universität Oldenburg, 26111 Oldenburg, Germany,Research Centre for Neurosensory Sciences, University of Oldenburg, 26111 Oldenburg, Germany
| | - Miriam Liedvogel
- Institut für Vogelforschung “Vogelwarte Helgoland”, An Der Vogelwarte 21, 26386, Wilhelmshaven, Germany,MPRG Behavioural Genomics, Max Planck Institute for Evolutionary Biology, 24306 Plön, Germany
| | - Lars Burnus
- AG ‘Neurosensorik/Animal Navigation’, Carl-von-Ossietzky Universität Oldenburg, 26111 Oldenburg, Germany,Research Centre for Neurosensory Sciences, University of Oldenburg, 26111 Oldenburg, Germany
| | - Raisa Chetverikova
- AG ‘Neurosensorik/Animal Navigation’, Carl-von-Ossietzky Universität Oldenburg, 26111 Oldenburg, Germany,Research Centre for Neurosensory Sciences, University of Oldenburg, 26111 Oldenburg, Germany
| | - Sara Döge
- AG ‘Neurosensorik/Animal Navigation’, Carl-von-Ossietzky Universität Oldenburg, 26111 Oldenburg, Germany,Research Centre for Neurosensory Sciences, University of Oldenburg, 26111 Oldenburg, Germany
| | - Thiemo Karwinkel
- Institut für Vogelforschung “Vogelwarte Helgoland”, An Der Vogelwarte 21, 26386, Wilhelmshaven, Germany,AG ‘Neurosensorik/Animal Navigation’, Carl-von-Ossietzky Universität Oldenburg, 26111 Oldenburg, Germany,Research Centre for Neurosensory Sciences, University of Oldenburg, 26111 Oldenburg, Germany
| | - Dmitry Kobylkov
- AG ‘Neurosensorik/Animal Navigation’, Carl-von-Ossietzky Universität Oldenburg, 26111 Oldenburg, Germany,Research Centre for Neurosensory Sciences, University of Oldenburg, 26111 Oldenburg, Germany,Center for Mind/Brain Science, University of Trento, Piazza Manifattura 1, 38068 Rovereto, TN, Italy
| | - Jingjing Xu
- AG ‘Neurosensorik/Animal Navigation’, Carl-von-Ossietzky Universität Oldenburg, 26111 Oldenburg, Germany,Research Centre for Neurosensory Sciences, University of Oldenburg, 26111 Oldenburg, Germany
| | - Henrik Mouritsen
- AG ‘Neurosensorik/Animal Navigation’, Carl-von-Ossietzky Universität Oldenburg, 26111 Oldenburg, Germany,Research Centre for Neurosensory Sciences, University of Oldenburg, 26111 Oldenburg, Germany
| |
Collapse
|
4
|
Pophof B, Henschenmacher B, Kattnig DR, Kuhne J, Vian A, Ziegelberger G. Biological Effects of Electric, Magnetic, and Electromagnetic Fields from 0 to 100 MHz on Fauna and Flora: Workshop Report. HEALTH PHYSICS 2023; 124:39-52. [PMID: 36480584 PMCID: PMC9722389 DOI: 10.1097/hp.0000000000001624] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
This report summarizes effects of anthropogenic electric, magnetic, and electromagnetic fields in the frequency range from 0 to 100 MHz on flora and fauna, as presented at an international workshop held on 5-7 November in 2019 in Munich, Germany. Such fields may originate from overhead powerlines, earth or sea cables, and from wireless charging systems. Animals and plants react differentially to anthropogenic fields; the mechanisms underlying these responses are still researched actively. Radical pairs and magnetite are discussed mechanisms of magnetoreception in insects, birds, and mammals. Moreover, several insects as well as marine species possess specialized electroreceptors, and behavioral reactions to anthropogenic fields have been reported. Plants react to experimental modifications of their magnetic environment by growth changes. Strong adverse effects of anthropogenic fields have not been described, but knowledge gaps were identified; further studies, aiming at the identification of the interaction mechanisms and the ecological consequences, are recommended.
Collapse
Affiliation(s)
- Blanka Pophof
- Competence Centre for Electromagnetic Fields, Department of Effects and Risks of Ionizing and Non-Ionizing Radiation, Federal Office for Radiation Protection, 85764 Oberschleißheim, Germany
| | - Bernd Henschenmacher
- Competence Centre for Electromagnetic Fields, Department of Effects and Risks of Ionizing and Non-Ionizing Radiation, Federal Office for Radiation Protection, 85764 Oberschleißheim, Germany
| | - Daniel R. Kattnig
- Department of Physics and Living Systems Institute, University of Exeter, Stocker Road, Exeter, EX4 4QD, United Kingdom
| | - Jens Kuhne
- Competence Centre for Electromagnetic Fields, Department of Effects and Risks of Ionizing and Non-Ionizing Radiation, Federal Office for Radiation Protection, 85764 Oberschleißheim, Germany
| | - Alain Vian
- Univ Angers, Institut Agro, INRAE, IRHS, SFR QUASAV, F-49000 Angers, France
| | - Gunde Ziegelberger
- Competence Centre for Electromagnetic Fields, Department of Effects and Risks of Ionizing and Non-Ionizing Radiation, Federal Office for Radiation Protection, 85764 Oberschleißheim, Germany
| |
Collapse
|
5
|
Sensitivity threshold of avian magnetic compass to oscillating magnetic field is species-specific. Behav Ecol Sociobiol 2023. [DOI: 10.1007/s00265-022-03282-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|
6
|
Smith LD, Chowdhury FT, Peasgood I, Dawkins N, Kattnig DR. Driven Radical Motion Enhances Cryptochrome Magnetoreception: Toward Live Quantum Sensing. J Phys Chem Lett 2022; 13:10500-10506. [PMID: 36332112 PMCID: PMC9677492 DOI: 10.1021/acs.jpclett.2c02840] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 10/25/2022] [Indexed: 06/16/2023]
Abstract
The mechanism underlying magnetoreception has long eluded explanation. A popular hypothesis attributes this sense to the quantum coherent spin dynamics and spin-selective recombination reactions of radical pairs in the protein cryptochrome. However, concerns about the validity of the hypothesis have been raised because unavoidable inter-radical interactions, such as the strong electron-electron dipolar coupling, appear to suppress its sensitivity. We demonstrate that sensitivity can be restored by driving the spin system through a modulation of the inter-radical distance. It is shown that this dynamical process markedly enhances geomagnetic field sensitivity in strongly coupled radical pairs via Landau-Zener-Stückelberg-Majorana transitions between singlet and triplet states. These findings suggest that a "live" harmonically driven magnetoreceptor can be more sensitive than its "dead" static counterpart.
Collapse
|
7
|
Morphology, biochemistry and connectivity of Cluster N and the hippocampal formation in a migratory bird. Brain Struct Funct 2022; 227:2731-2749. [DOI: 10.1007/s00429-022-02566-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 09/05/2022] [Indexed: 11/02/2022]
Abstract
AbstractThe exceptional navigational capabilities of migrating birds are based on the perception and integration of a variety of natural orientation cues. The “Wulst” in the forebrain of night-migratory songbirds contains a brain area named “Cluster N”, which is involved in processing directional navigational information derived from the Earth´s magnetic field. Cluster N is medially joined by the hippocampal formation, known to retrieve and utilise navigational information. To investigate the connectivity and neurochemical characteristics of Cluster N and the hippocampal formation of migratory birds, we performed morphological and histochemical analyses based on the expression of calbindin, calretinin, parvalbumin, glutamate receptor type 1 and early growth response protein-1 in the night-migratory Garden warbler (Sylvia borin) and mapped their mutual connections using neuronal tract tracing. The resulting expression patterns revealed regionally restricted neurochemical features, which mapped well onto the hippocampal and hyperpallial substructures known from other avian species. Magnetic field-induced neuronal activation covered caudal parts of the hyperpallium and the medially adjacent hippocampal dorsomedial/dorsolateral subdivisions. Neuronal tract tracings revealed connections between Cluster N and the hippocampal formation with the vast majority originating from the densocellular hyperpallium, either directly or indirectly via the area corticoidea dorsolateralis. Our data indicate that the densocellular hyperpallium could represent a central relay for the transmission of magnetic compass information to the hippocampal formation where it might be integrated with other navigational cues in night-migratory songbirds.
Collapse
|
8
|
Ramsay J, Kattnig DR. Radical triads, not pairs, may explain effects of hypomagnetic fields on neurogenesis. PLoS Comput Biol 2022; 18:e1010519. [PMID: 36108063 PMCID: PMC9514667 DOI: 10.1371/journal.pcbi.1010519] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 09/27/2022] [Accepted: 08/27/2022] [Indexed: 12/03/2022] Open
Abstract
Adult hippocampal neurogenesis and hippocampus-dependent cognition in mice have been found to be adversely affected by hypomagnetic field exposure. The effect concurred with a reduction of reactive oxygen species in the absence of the geomagnetic field. A recent theoretical study suggests a mechanistic interpretation of this phenomenon in the framework of the Radical Pair Mechanism. According to this model, a flavin-superoxide radical pair, born in the singlet spin configuration, undergoes magnetic field-dependent spin dynamics such that the pair’s recombination is enhanced as the applied magnetic field is reduced. This model has two ostensible weaknesses: a) the assumption of a singlet initial state is irreconcilable with known reaction pathways generating such radical pairs, and b) the model neglects the swift spin relaxation of free superoxide, which abolishes any magnetic sensitivity in geomagnetic/hypomagnetic fields. We here suggest that a model based on a radical triad and the assumption of a secondary radical scavenging reaction can, in principle, explain the phenomenon without unnatural assumptions, thus providing a coherent explanation of hypomagnetic field effects in biology. The hippocampal region of the brain plays a major role in learning and memory functionality. In male mice, shielding of the Earth’s magnetic field was found to decrease hippocampal neurogenesis, i.e. the formation of new neurons, following from a decrease in levels of reactive oxygen species. In this study, we suggest an explanation in terms of spin dynamics of a three radical system composed of flavin-semiquinone, superoxide and ascorbyl radical. This model agrees with the experimental data whilst retaining realistic parameters for a biological system, unlike the Radical Pair Mechanism.
Collapse
Affiliation(s)
- Jess Ramsay
- Living Systems Institute and Department of Physics, University of Exeter, Exeter, Devon, United Kingdom
| | - Daniel R. Kattnig
- Living Systems Institute and Department of Physics, University of Exeter, Exeter, Devon, United Kingdom
- * E-mail:
| |
Collapse
|
9
|
Pakhomov A, Prokshina A, Cellarius F, Mouritsen H, Chernetsov N. Access to the sky near the horizon and stars does not play a crucial role in compass calibration of European songbird migrants. J Exp Biol 2022; 225:276374. [PMID: 35903997 DOI: 10.1242/jeb.243631] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 07/27/2022] [Indexed: 11/20/2022]
Abstract
Migratory birds use different global cues including celestial and magnetic information to determine and maintain their seasonally appropriate migratory direction. A hierarchy among different compass systems in songbird migrants is still a matter for discussion due to highly variable and apparently contradictory results obtained in various experimental studies. How birds decide whether or not and how they should calibrate their compasses before departure remains unclear. A recent "extended unified theory" suggested that access to both a view of the sky near the horizon and stars during the cue-conflict exposure might be crucial for the results of cue-conflict experiments. In this study, we performed cue-conflict experiments in three European songbird species with different migratory strategies (garden warblers Sylvia borin, pied flycatcher Ficedula hypoleuca and European robin Erithacus rubecula; juveniles and adults; spring and autumn migrations) using a uniform experimental protocol. We exposed birds to the natural celestial cues in a shifted (120° clock/counterclockwise) magnetic field from sunset to the end of the nautical twilight and tested them in orientation cages immediately after cue-conflict treatments. None of the species (apart from adult robins) showed any sign of calibration even if they had access to a view of the sky and local surroundings near the horizon and stars during cue-conflict treatments. Based on results of our experiments and data of previous contradictory studies, we suggest that no uniform theory can explain why birds calibrate or do not calibrate their compass systems. Each species (and possibly even different populations) may choose its calibration strategy differently.
Collapse
Affiliation(s)
- Alexander Pakhomov
- Biological Station Rybachy, Zoological Institute RAS, Rybachy 238535, Kaliningrad Region, Russia
| | - Anisia Prokshina
- Department of Vertebrate Zoology, Lomonosov Moscow State University, 119234 Moscow, Russia
| | - Fedor Cellarius
- Department of Vertebrate Zoology, Lomonosov Moscow State University, 119234 Moscow, Russia
| | - Henrik Mouritsen
- Institute for Biology and Environmental Sciences, Carl-von-Ossietzky-Universität Oldenburg, 26111 Oldenburg, Germany.,Research Centre for Neurosensory Sciences, Carl-von-Ossietzky-University Oldenburg, Carl-von-Ossietzky-Strasse 9-11, 26129 Oldenburg, Germany
| | - Nikita Chernetsov
- Biological Station Rybachy, Zoological Institute RAS, Rybachy 238535, Kaliningrad Region, Russia.,Department of Vertebrate Zoology, St. Petersburg State University, 199034 St. Petersburg, Russia
| |
Collapse
|
10
|
Hanić M, Schuhmann F, Frederiksen A, Langebrake C, Manthey G, Liedvogel M, Xu J, Mouritsen H, Solov'yov IA. Computational Reconstruction and Analysis of Structural Models of Avian Cryptochrome 4. J Phys Chem B 2022; 126:4623-4635. [PMID: 35704801 DOI: 10.1021/acs.jpcb.2c00878] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A recent study by Xu et al. (Nature, 2021, 594, 535-540) provided strong evidence that cryptochrome 4 (Cry4) is a key protein to endow migratory birds with the magnetic compass sense. The investigation compared the magnetic field response of Cry4 from migratory and nonmigratory bird species and suggested that a difference in magnetic sensitivity could exist. This finding prompted an in-depth investigation into Cry4 protein differences on the structural and dynamic levels. In the present study, the pigeon Cry4 (ClCry4) crystal structure was used to reconstruct the missing avian Cry4 protein structures via homology modeling for carefully selected bird species. The reconstructed Cry4 structure from European robin, Eurasian blackcap, zebra finch, chicken, and pigeon were subsequently simulated dynamically and analyzed. The studied avian Cry4 structures show flexibility in analogous regions pointing to similar activation mechanisms and/or signaling interaction partners. It can be concluded that the experimentally recorded difference in the magnetic field sensitivity of Cry4 from different birds is unlikely to be due to solely intrinsic dynamics of the proteins but requires additional factors that have not yet been identified.
Collapse
Affiliation(s)
- Maja Hanić
- Department of Physics, Carl von Ossietzky University of Oldenburg, Carl-von-Ossietzky Straße 9-11, Oldenburg 26129, Germany
| | - Fabian Schuhmann
- Department of Physics, Carl von Ossietzky University of Oldenburg, Carl-von-Ossietzky Straße 9-11, Oldenburg 26129, Germany
| | - Anders Frederiksen
- Department of Physics, Carl von Ossietzky University of Oldenburg, Carl-von-Ossietzky Straße 9-11, Oldenburg 26129, Germany
| | - Corinna Langebrake
- Institute of Avian Research, An der Vogelwarte 21, Wilhelmshaven 26386, Germany
| | - Georg Manthey
- Department of Physics, Carl von Ossietzky University of Oldenburg, Carl-von-Ossietzky Straße 9-11, Oldenburg 26129, Germany.,Institute of Avian Research, An der Vogelwarte 21, Wilhelmshaven 26386, Germany
| | - Miriam Liedvogel
- Institute of Avian Research, An der Vogelwarte 21, Wilhelmshaven 26386, Germany.,Department of Biology and Environmental Sciences, Carl von Ossietzky University of Oldenburg, Carl-von-Ossietzky Straße 9-11, Oldenburg 26129, Germany.,MPRG Behavioural Genomics, Max Planck Institute for Evolutionary Biology, Plön 24306, Germany
| | - Jingjing Xu
- Department of Biology and Environmental Sciences, Carl von Ossietzky University of Oldenburg, Carl-von-Ossietzky Straße 9-11, Oldenburg 26129, Germany
| | - Henrik Mouritsen
- Department of Biology and Environmental Sciences, Carl von Ossietzky University of Oldenburg, Carl-von-Ossietzky Straße 9-11, Oldenburg 26129, Germany.,Research Center for Neurosensory Sciences, Carl von Ossietzky University of Oldenburg, Carl-von-Ossietzky Straße 9-11, Oldenburg 26129, Germany
| | - Ilia A Solov'yov
- Department of Physics, Carl von Ossietzky University of Oldenburg, Carl-von-Ossietzky Straße 9-11, Oldenburg 26129, Germany.,Research Center for Neurosensory Sciences, Carl von Ossietzky University of Oldenburg, Carl-von-Ossietzky Straße 9-11, Oldenburg 26129, Germany.,Center for Nanoscale Dynamics (CENAD), Carl von Ossietzky Universität Oldenburg, Institut für Physik, Ammerländer Heerstr. 114-118, 26129 Oldenburg, Germany
| |
Collapse
|
11
|
Smith LD, Deviers J, Kattnig DR. Observations about utilitarian coherence in the avian compass. Sci Rep 2022; 12:6011. [PMID: 35397661 PMCID: PMC8994785 DOI: 10.1038/s41598-022-09901-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Accepted: 03/29/2022] [Indexed: 11/09/2022] Open
Abstract
It is hypothesised that the avian compass relies on spin dynamics in a recombining radical pair. Quantum coherence has been suggested as a resource to this process that nature may utilise to achieve increased compass sensitivity. To date, the true functional role of coherence in these natural systems has remained speculative, lacking insights from sufficiently complex models. Here, we investigate realistically large radical pair models with up to 21 nuclear spins, inspired by the putative magnetosensory protein cryptochrome. By varying relative radical orientations, we reveal correlations of several coherence measures with compass fidelity. Whilst electronic coherence is found to be an ineffective predictor of compass sensitivity, a robust correlation of compass sensitivity and a global coherence measure is established. The results demonstrate the importance of realistic models, and appropriate choice of coherence measure, in elucidating the quantum nature of the avian compass.
Collapse
Affiliation(s)
- Luke D Smith
- Living Systems Institute and Department of Physics, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK
| | - Jean Deviers
- Living Systems Institute and Department of Physics, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK
| | - Daniel R Kattnig
- Living Systems Institute and Department of Physics, University of Exeter, Stocker Road, Exeter, EX4 4QD, UK.
| |
Collapse
|
12
|
Granger J, Cummer SA, Lohmann KJ, Johnsen S. Environmental sources of radio frequency noise: potential impacts on magnetoreception. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2022; 208:83-95. [DOI: 10.1007/s00359-021-01516-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 10/07/2021] [Accepted: 10/13/2021] [Indexed: 11/27/2022]
|
13
|
Deviers J, Cailliez F, de la Lande A, Kattnig DR. Anisotropic magnetic field effects in the re-oxidation of cryptochrome in the presence of scavenger radicals. J Chem Phys 2022; 156:025101. [PMID: 35032990 DOI: 10.1063/5.0078115] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The avian compass and many other of nature's magnetoreceptive traits are widely ascribed to the protein cryptochrome. There, magnetosensitivity is thought to emerge as the spin dynamics of radicals in the applied magnetic field enters in competition with their recombination. The first and dominant model makes use of a radical pair. However, recent studies have suggested that magnetosensitivity could be markedly enhanced for a radical triad, the primary radical pair of which undergoes a spin-selective recombination reaction with a third radical. Here, we test the practicality of this supposition for the reoxidation reaction of the reduced FAD cofactor in cryptochrome, which has been implicated with light-independent magnetoreception but appears irreconcilable with the classical radical pair mechanism (RPM). Based on the available realistic cryptochrome structures, we predict the magnetosensitivity of radical triad systems comprising the flavin semiquinone, the superoxide, and a tyrosine or ascorbyl scavenger radical. We consider many hyperfine-coupled nuclear spins, the relative orientation and placement of the radicals, their coupling by the electron-electron dipolar interaction, and spin relaxation in the superoxide radical in the limit of instantaneous decoherence, which have not been comprehensively considered before. We demonstrate that these systems can provide superior magnetosensitivity under realistic conditions, with implications for dark-state cryptochrome magnetoreception and other biological magneto- and isotope-sensitive radical recombination reactions.
Collapse
Affiliation(s)
- Jean Deviers
- Department of Physics and Living Systems Institute, University of Exeter, Stocker Road, EX4 4QD Exeter, United Kingdom
| | - Fabien Cailliez
- Institut de Chimie Physique, Université Paris Saclay, CNRS (UMR 8000), 15 avenue Jean Perrin, 91405 Orsay, France
| | - Aurélien de la Lande
- Institut de Chimie Physique, Université Paris Saclay, CNRS (UMR 8000), 15 avenue Jean Perrin, 91405 Orsay, France
| | - Daniel R Kattnig
- Department of Physics and Living Systems Institute, University of Exeter, Stocker Road, EX4 4QD Exeter, United Kingdom
| |
Collapse
|
14
|
Broadband 75-85 MHz radiofrequency fields disrupt magnetic compass orientation in night-migratory songbirds consistent with a flavin-based radical pair magnetoreceptor. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2022; 208:97-106. [PMID: 35019998 PMCID: PMC8918455 DOI: 10.1007/s00359-021-01537-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 12/15/2021] [Accepted: 12/17/2021] [Indexed: 12/20/2022]
Abstract
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 of magnetoreception as observed for isolated cryptochrome 4, a protein found in birds’ retinas. The exact identity of the magnetically sensitive radicals in cryptochrome is uncertain in vivo, but their formation seems to require a bound flavin adenine dinucleotide chromophore and a chain of four tryptophan residues within the protein. Resulting from the hyperfine interactions of nuclear spins with the unpaired electrons, the sensitivity of the radicals to radiofrequency magnetic fields depends strongly on the number of magnetic nuclei (hydrogen and nitrogen atoms) they contain. Quantum-chemical calculations suggested that electromagnetic noise in the frequency range 75–85 MHz could give information about the identity of the radicals involved. Here, we show that broadband 75–85 MHz radiofrequency fields prevent a night-migratory songbird from using its magnetic compass in behavioural experiments. These results indicate that at least one of the components of the radical pair involved in the sensory process of avian magnetoreception must contain a substantial number of strong hyperfine interactions as would be the case if a flavin–tryptophan radical pair were the magnetic sensor.
Collapse
|
15
|
Babcock N, Kattnig DR. Radical Scavenging Could Answer the Challenge Posed by Electron-Electron Dipolar Interactions in the Cryptochrome Compass Model. JACS AU 2021; 1:2033-2046. [PMID: 34841416 PMCID: PMC8611662 DOI: 10.1021/jacsau.1c00332] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Indexed: 06/13/2023]
Abstract
Many birds are endowed with a visual magnetic sense that may exploit magnetosensitive radical recombination processes in the protein cryptochrome. In this widely accepted but unproven model, geomagnetic sensitivity is suggested to arise from variations in the recombination rate of a pair of radicals, whose unpaired electron spins undergo coherent singlet-triplet interconversion in the geomagnetic field by coupling to nuclear spins via hyperfine interactions. However, simulations of this conventional radical pair mechanism (RPM) predicted only tiny magnetosensitivities for realistic conditions because the RPM's directional sensitivity is strongly suppressed by the intrinsic electron-electron dipolar (EED) interactions, casting doubt on its viability as a magnetic sensor. We show how this RPM-suppression problem is overcome in a three-radical system in which a third "scavenger" radical reacts with one member of the primary pair. We use this finding to predict substantial magnetic field effects that exceed those of the RPM in the presence of EED interactions in animal cryptochromes.
Collapse
Affiliation(s)
- Nathan
Sean Babcock
- Quantum
Biology Laboratory, Howard University, 2400 Sixth Street NW, Washington District of Columbia, 20059, United States of America
- Living
Systems Institute and Department of Physics University of Exeter, Stocker Road, Exeter, EX4 4QD, United Kingdom
| | - Daniel R. Kattnig
- Living
Systems Institute and Department of Physics University of Exeter, Stocker Road, Exeter, EX4 4QD, United Kingdom
| |
Collapse
|
16
|
Wong SY, Solov'yov IA, Hore PJ, Kattnig DR. Nuclear polarization effects in cryptochrome-based magnetoreception. J Chem Phys 2021; 154:035102. [PMID: 33499614 DOI: 10.1063/5.0038947] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The mechanism of the magnetic compass sense of migratory songbirds is thought to involve magnetically sensitive chemical reactions of light-induced radical pairs in cryptochrome proteins located in the birds' eyes. However, it is not yet clear whether this mechanism would be sensitive enough to form the basis of a viable compass. In the present work, we report spin dynamics simulations of models of cryptochrome-based radical pairs to assess whether accumulation of nuclear spin polarization in multiple photocycles could lead to significant enhancements in the sensitivity with which the proteins respond to the direction of the geomagnetic field. Although buildup of nuclear polarization appears to offer sensitivity advantages in the more idealized model systems studied, we find that these enhancements do not carry over to conditions that more closely resemble the situation thought to exist in vivo. On the basis of these simulations, we conclude that buildup of nuclear polarization seems unlikely to be a source of significant improvements in the performance of cryptochrome-based radical pair magnetoreceptors.
Collapse
Affiliation(s)
- Siu Ying Wong
- Institut für Physik, Carl-von-Ossietzky Universität Oldenburg, 26111 Oldenburg, Germany
| | - Ilia A Solov'yov
- Institut für Physik, Carl-von-Ossietzky Universität Oldenburg, 26111 Oldenburg, Germany
| | - P J Hore
- Department of Chemistry, University of Oxford, Oxford OX1 3QZ, United Kingdom
| | - Daniel R Kattnig
- Living Systems Institute and Department of Physics, University of Exeter, Exeter EX4 4QD, United Kingdom
| |
Collapse
|
17
|
Ren Y, Hiscock HG, Hore PJ. Angular Precision of Radical Pair Compass Magnetoreceptors. Biophys J 2021; 120:547-555. [PMID: 33421412 PMCID: PMC7896030 DOI: 10.1016/j.bpj.2020.12.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 12/17/2020] [Accepted: 12/30/2020] [Indexed: 11/19/2022] Open
Abstract
The light-dependent magnetic compass sense of night-migratory songbirds is thought to rely on magnetically sensitive chemical reactions of radical pairs in cryptochrome proteins located in the birds' eyes. Recently, an information theory approach was developed that provides a strict lower bound on the precision with which a bird could estimate its head direction using only geomagnetic cues and a cryptochrome-based radical pair sensor. By means of this lower bound, we show here how the performance of the compass sense could be optimized by adjusting the orientation of cryptochrome molecules within photoreceptor cells, the distribution of cells around the retina, and the effects of the geomagnetic field on the photochemistry of the radical pair.
Collapse
Affiliation(s)
- Yi Ren
- Department of Chemistry, University of Oxford, Oxford, United Kingdom
| | - Hamish G Hiscock
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - P J Hore
- Department of Chemistry, University of Oxford, Oxford, United Kingdom.
| |
Collapse
|
18
|
Natal imprinting to the Earth’s magnetic field in a pelagic seabird. Curr Biol 2020; 30:2869-2873.e2. [DOI: 10.1016/j.cub.2020.05.039] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/06/2020] [Accepted: 05/11/2020] [Indexed: 11/20/2022]
|