1
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Akimoto T, Islam MR, Nagasako A, Kishi K, Nakakaji R, Ohtake M, Hasumi H, Yamaguchi T, Yamada S, Yamamoto T, Ishikawa Y, Umemura M. Alternative magnetic field exposure suppresses tumor growth via metabolic reprogramming. Cancer Sci 2024; 115:2686-2700. [PMID: 38877783 PMCID: PMC11309929 DOI: 10.1111/cas.16243] [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: 02/07/2024] [Revised: 05/23/2024] [Accepted: 05/28/2024] [Indexed: 06/16/2024] Open
Abstract
Application of physical forces, ranging from ultrasound to electric fields, is recommended in various clinical practice guidelines, including those for treating cancers and bone fractures. However, the mechanistic details of such treatments are often inadequately understood, primarily due to the absence of comprehensive study models. In this study, we demonstrate that an alternating magnetic field (AMF) inherently possesses a direct anti-cancer effect by enhancing oxidative phosphorylation (OXPHOS) and thereby inducing metabolic reprogramming. We observed that the proliferation of human glioblastoma multiforme (GBM) cells (U87 and LN229) was inhibited upon exposure to AMF within a specific narrow frequency range, including around 227 kHz. In contrast, this exposure did not affect normal human astrocytes (NHA). Additionally, in mouse models implanted with human GBM cells in the brain, daily exposure to AMF for 30 min over 21 days significantly suppressed tumor growth and prolonged overall survival. This effect was associated with heightened reactive oxygen species (ROS) production and increased manganese superoxide dismutase (MnSOD) expression. The anti-cancer efficacy of AMF was diminished by either a mitochondrial complex IV inhibitor or a ROS scavenger. Along with these observations, there was a decrease in the extracellular acidification rate (ECAR) and an increase in the oxygen consumption rate (OCR). This suggests that AMF-induced metabolic reprogramming occurs in GBM cells but not in normal cells. Our results suggest that AMF exposure may offer a straightforward strategy to inhibit cancer cell growth by leveraging oxidative stress through metabolic reprogramming.
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Affiliation(s)
- Taisuke Akimoto
- Department of NeurosurgeryYokohama City University Graduate School of MedicineYokohamaKanagawaJapan
| | - Md Rafikul Islam
- Department of Biochemistry and Molecular BiologyWinthrop P. Rockefeller Cancer Institute, University of Arkansas for Medical Sciences (UAMS)Little RockArkansasUSA
| | - Akane Nagasako
- Cardiovascular Research InstituteYokohama City University Graduate School of MedicineYokohamaKanagawaJapan
| | | | - Rina Nakakaji
- Cardiovascular Research InstituteYokohama City University Graduate School of MedicineYokohamaKanagawaJapan
| | - Makoto Ohtake
- Department of NeurosurgeryYokohama City University Graduate School of MedicineYokohamaKanagawaJapan
| | - Hisashi Hasumi
- Department of Urology, Yokohama City University Graduate School of MedicineYokohamaKanagawaJapan
| | | | - Shigeki Yamada
- Department of Materials System Science, Yokohama City University Graduate School of MedicineYokohamaKanagawaJapan
| | - Tetsuya Yamamoto
- Department of NeurosurgeryYokohama City University Graduate School of MedicineYokohamaKanagawaJapan
| | - Yoshihiro Ishikawa
- Cardiovascular Research InstituteYokohama City University Graduate School of MedicineYokohamaKanagawaJapan
| | - Masanari Umemura
- Cardiovascular Research InstituteYokohama City University Graduate School of MedicineYokohamaKanagawaJapan
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2
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Kretschmer K, Frederiksen A, Reinholdt P, Kongsted J, Solov’yov IA. Understanding the Red Shift in the Absorption Spectrum of the FAD Cofactor in ClCry4 Protein. J Phys Chem B 2024; 128:5320-5326. [PMID: 38805723 PMCID: PMC11163422 DOI: 10.1021/acs.jpcb.4c00710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 05/03/2024] [Accepted: 05/16/2024] [Indexed: 05/30/2024]
Abstract
It is still a puzzle that has not been entirely solved how migratory birds utilize the Earth's magnetic field for biannual migration. The most consistent explanation thus far is rooted in the modulation of the biological function of the cryptochrome 4 (Cry4) protein by an external magnetic field. This phenomenon is closely linked with the flavin adenine dinucleotide (FAD) cofactor that is noncovalently bound in the protein. Cry4 is activated by blue light, which is absorbed by the FAD cofactor. Subsequent electron and proton transfers trigger radical pair formation in the protein, which is sensitive to the external magnetic field. An important long-lasting redox state of the FAD cofactor is the signaling (FADH•) state, which is present after the transient electron transfer steps have been completed. Recent experimental efforts succeeded in crystallizing the Cry4 protein from Columbia livia (ClCry4) with all of the important residues needed for protein photoreduction. This specific crystallization of Cry4 protein so far is the only avian cryptochrome crystal structure available, which, however, has great similarity to the Cry4 proteins of night migratory birds. The previous experimental studies of the ClCry4 protein included the absorption properties of the protein in its different redox states. The absorption spectrum of the FADH• state demonstrated a peculiar red shift compared to the photoabsorption properties of the FAD cofactor in its FADH• state in other Cry proteins from other species. The aim of this study is to understand this red shift by employing the tools of computational microscopy and, in particular, a QM/MM approach that relies on the polarizable embedding approximation.
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Affiliation(s)
- Katarina Kretschmer
- Institute of Physics, Carl von Ossietzky Universität Oldenburg, Carl-von-Ossietzky Str. 9-11, 26129 Oldenburg, Germany
| | - Anders Frederiksen
- Institute of Physics, Carl von Ossietzky Universität Oldenburg, Carl-von-Ossietzky Str. 9-11, 26129 Oldenburg, Germany
| | - Peter Reinholdt
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK 5230 Odense, Denmark
| | - Jacob Kongsted
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK 5230 Odense, Denmark
| | - Ilia A. Solov’yov
- Institute of Physics, Carl von Ossietzky Universität Oldenburg, Carl-von-Ossietzky Str. 9-11, 26129 Oldenburg, Germany
- Research Centre for Neurosensory
Science, Carl von Ossietzky Universität
Oldenburg, Carl-von-Ossietzky
Str. 9-11, 26129 Oldenburg, Germany
- Center
for Nanoscale Dynamics (CENAD), Carl von
Ossietzky Universität Oldenburg, Ammerländer Heerstr. 114-118, 26129 Oldenburg, Germany
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3
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Thoradit T, Thongyoo K, Kamoltheptawin K, Tunprasert L, El-Esawi MA, Aguida B, Jourdan N, Buddhachat K, Pooam M. Cryptochrome and quantum biology: unraveling the mysteries of plant magnetoreception. FRONTIERS IN PLANT SCIENCE 2023; 14:1266357. [PMID: 37860259 PMCID: PMC10583551 DOI: 10.3389/fpls.2023.1266357] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 09/14/2023] [Indexed: 10/21/2023]
Abstract
Magnetoreception, the remarkable ability of organisms to perceive and respond to Earth's magnetic field, has captivated scientists for decades, particularly within the field of quantum biology. In the plant science, the exploration of the complicated interplay between quantum phenomena and classical biology in the context of plant magnetoreception has emerged as an attractive area of research. This comprehensive review investigates into three prominent theoretical models: the Radical Pair Mechanism (RPM), the Level Crossing Mechanism (LCM), and the Magnetite-based MagR theory in plants. While examining the advantages, limitations, and challenges associated with each model, this review places a particular weight on the RPM, highlighting its well-established role of cryptochromes and in-vivo experiments on light-independent plant magnetoreception. However, alternative mechanisms such as the LCM and the MagR theory are objectively presented as convincing perspectives that permit further investigation. To shed light on these theoretical frameworks, this review proposes experimental approaches including cutting-edge experimental techniques. By integrating these approaches, a comprehensive understanding of the complex mechanisms driving plant magnetoreception can be achieved, lending support to the fundamental principle in the RPM. In conclusion, this review provides a panoramic overview of plant magnetoreception, highlighting the exciting potential of quantum biology in unraveling the mysteries of magnetoreception. As researchers embark on this captivating scientific journey, the doors to deciphering the diverse mechanisms of magnetoreception in plants stand wide open, offering a profound exploration of nature's adaptations to environmental cues.
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Affiliation(s)
- Thawatchai Thoradit
- Department of Biology, Faculty of Science, Naresuan University, Phitsanulok, Thailand
| | - Kanjana Thongyoo
- Department of Biology, Faculty of Science, Naresuan University, Phitsanulok, Thailand
| | | | - Lalin Tunprasert
- Department of Biology, Faculty of Science, Naresuan University, Phitsanulok, Thailand
- State Key Laboratory for Mechanical Behavior of Materials, School of Material Science and Engineering, Xi’an Jiaotong University, Xi’an, China
| | | | - Blanche Aguida
- UMR CNRS 8256 Adaptation biologique et vieillissement (B2A), Institute of Biology Paris Seine, Sorbonne Université, Paris, France
| | - Nathalie Jourdan
- UMR CNRS 8256 Adaptation biologique et vieillissement (B2A), Institute of Biology Paris Seine, Sorbonne Université, Paris, France
| | - Kittisak Buddhachat
- Department of Biology, Faculty of Science, Naresuan University, Phitsanulok, Thailand
| | - Marootpong Pooam
- Department of Biology, Faculty of Science, Naresuan University, Phitsanulok, Thailand
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4
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Zadeh-Haghighi H, Simon C. Magnetic field effects in biology from the perspective of the radical pair mechanism. J R Soc Interface 2022; 19:20220325. [PMID: 35919980 PMCID: PMC9346374 DOI: 10.1098/rsif.2022.0325] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 07/14/2022] [Indexed: 04/07/2023] Open
Abstract
Hundreds of studies have found that weak magnetic fields can significantly influence various biological systems. However, the underlying mechanisms behind these phenomena remain elusive. Remarkably, the magnetic energies implicated in these effects are much smaller than thermal energies. Here, we review these observations, and we suggest an explanation based on the radical pair mechanism, which involves the quantum dynamics of the electron and nuclear spins of transient radical molecules. While the radical pair mechanism has been studied in detail in the context of avian magnetoreception, the studies reviewed here show that magnetosensitivity is widespread throughout biology. We review magnetic field effects on various physiological functions, discussing static, hypomagnetic and oscillating magnetic fields, as well as isotope effects. We then review the radical pair mechanism as a potential unifying model for the described magnetic field effects, and we discuss plausible candidate molecules for the radical pairs. We review recent studies proposing that the radical pair mechanism provides explanations for isotope effects in xenon anaesthesia and lithium treatment of hyperactivity, magnetic field effects on the circadian clock, and hypomagnetic field effects on neurogenesis and microtubule assembly. We conclude by discussing future lines of investigation in this exciting new area of quantum biology.
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Affiliation(s)
- Hadi Zadeh-Haghighi
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada T2N 1N4
- Institute for Quantum Science and Technology, University of Calgary, Calgary, Alberta, Canada T2N 1N4
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada T2N 1N4
| | - Christoph Simon
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada T2N 1N4
- Institute for Quantum Science and Technology, University of Calgary, Calgary, Alberta, Canada T2N 1N4
- Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada T2N 1N4
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5
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Abstract
The ability to detect magnetic fields is a sensory modality that is used by many animals to navigate. While first postulated in the 1800s, for decades, it was considered a biological myth. A series of elegant behavioral experiments in the 1960s and 1970s showed conclusively that the sense is real; however, the underlying mechanism(s) remained unresolved. Consequently, this has given rise to a series of beliefs that are critically analyzed in this manuscript. We address six assertions: (1) Magnetoreception does not exist; (2) It has to be magnetite; (3) Birds have a conserved six loci magnetic sense system in their upper beak; (4) It has to be cryptochrome; (5) MagR is a protein biocompass; and (6) The electromagnetic induction hypothesis is dead. In advancing counter-arguments for these beliefs, we hope to stimulate debate, new ideas, and the design of well-controlled experiments that can aid our understanding of this fascinating biological phenomenon.
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Affiliation(s)
- Simon Nimpf
- Division of Neurobiology, Faculty of Biology, Ludwig-Maximilians-University Munich, Planegg-Martinsried, 82152 Munich, Germany
| | - David A Keays
- Division of Neurobiology, Faculty of Biology, Ludwig-Maximilians-University Munich, Planegg-Martinsried, 82152 Munich, Germany.,University of Cambridge, Department of Physiology, Development & Neuroscience, Downing Street, CB2 3EG Cambridge, UK.,Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), Campus- Vienna-Biocenter 1, 1030 Vienna, Austria
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6
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Du N, Ye F, Sun J, Liu K. Stimuli-Responsive Natural Proteins and Their Applications. Chembiochem 2021; 23:e202100416. [PMID: 34773331 DOI: 10.1002/cbic.202100416] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Revised: 11/12/2021] [Indexed: 01/02/2023]
Abstract
Natural proteins are essential biomacromolecules that fulfill versatile functions in the living organism, such as their usage as cytoskeleton, nutriment transporter, homeostasis controller, catalyzer, or immune guarder. Due to the excellent mechanical properties and good biocompatibility/biodegradability, natural protein-based biomaterials are well equipped for prospective applications in various fields. Among these natural proteins, stimuli-responsive proteins can be reversibly and precisely manipulated on demand, rendering the protein-based biomaterials promising candidates for numerous applications, including disease detection, drug delivery, bio-sensing, and regenerative medicine. Therefore, we present some typical natural proteins with diverse physical stimuli-responsive properties, including temperature, light, force, electrical, and magnetic sensing in this review. The structure-function mechanism of these proteins is discussed in detail. Finally, we give a summary and perspective for the development of stimuli-responsive proteins.
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Affiliation(s)
- Na Du
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, 325001, P. R. China.,State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, P. R. China
| | - Fangfu Ye
- Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, 325001, P. R. China
| | - Jing Sun
- Institute of Organic Chemistry, University of Ulm, Albert-Einstein-Allee 11, 89081, Ulm, Germany
| | - Kai Liu
- State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, P. R. China.,Department of Chemistry, Tsinghua University, Beijing, 100084, P. R. China
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7
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Hamada M, Iwata T, Fuki M, Kandori H, Weber S, Kobori Y. Orientations and water dynamics of photoinduced secondary charge-separated states for magnetoreception by cryptochrome. Commun Chem 2021; 4:141. [PMID: 36697801 PMCID: PMC9814139 DOI: 10.1038/s42004-021-00573-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 09/02/2021] [Indexed: 01/28/2023] Open
Abstract
In the biological magnetic compass, blue-light photoreceptor protein of cryptochrome is thought to conduct the sensing of the Earth's magnetic field by photoinduced sequential long-range charge-separation (CS) through a cascade of tryptophan residues, WA(H), WB(H) and WC(H). Mechanism of generating the weak-field sensitive radical pair (RP) is poorly understood because geometries, electronic couplings and their modulations by molecular motion have not been investigated in the secondary CS states generated prior to the terminal RP states. In this study, water dynamics control of the electronic coupling is revealed to be a key concept for sensing the direction of weak magnetic field. Geometry and exchange coupling (singlet-triplet energy gap: 2J) of photoinduced secondary CS states composed of flavin adenine dinucleotide radical anion (FAD-•) and radical cation WB(H)+• in the cryptochrome DASH from Xenopus laevis were clarified by time-resolved electron paramagnetic resonance. We found a time-dependent energetic disorder in 2J and was interpreted by a trap CS state capturing one reorientated water molecule at 120 K. Enhanced electron-tunneling by water-libration was revealed for the terminal charge-separation event at elevated temperature. This highlights importance of optimizing the electronic coupling for regulation of the anisotropic RP yield on the possible magnetic compass senses.
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Affiliation(s)
- Misato Hamada
- grid.31432.370000 0001 1092 3077Department of Chemistry, Graduate School of Science, Kobe University, 1‒1 Rokkodai‒cho, Nada‒ku, Kobe, 657‒8501 Japan
| | - Tatsuya Iwata
- grid.265050.40000 0000 9290 9879Department of Pharmaceutical Sciences, Toho University, Funabashi, Chiba 274‒8510 Japan
| | - Masaaki Fuki
- grid.31432.370000 0001 1092 3077Department of Chemistry, Graduate School of Science, Kobe University, 1‒1 Rokkodai‒cho, Nada‒ku, Kobe, 657‒8501 Japan ,grid.31432.370000 0001 1092 3077Molecular Photoscience Research Center, Kobe University, 1‒1 Rokkodai‒cho, Nada‒ku, Kobe, 657‒8501 Japan
| | - Hideki Kandori
- grid.47716.330000 0001 0656 7591Department of Life Science and Applied Chemistry, Nagoya Institute of Technology, Showa-ku, Nagoya 466-8555 Japan ,grid.47716.330000 0001 0656 7591OptoBioTechnology Research Center, Nagoya Institute of Technology, Showa-ku, Nagoya 466-8555 Japan
| | - Stefan Weber
- grid.5963.9Institute of Physical Chemistry, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany
| | - Yasuhiro Kobori
- grid.31432.370000 0001 1092 3077Department of Chemistry, Graduate School of Science, Kobe University, 1‒1 Rokkodai‒cho, Nada‒ku, Kobe, 657‒8501 Japan ,grid.31432.370000 0001 1092 3077Molecular Photoscience Research Center, Kobe University, 1‒1 Rokkodai‒cho, Nada‒ku, Kobe, 657‒8501 Japan
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8
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Tyagi T, Bhardwaj SK. Magnetic Compass Orientation in a Palaearctic-Indian Night Migrant, the Red-Headed Bunting. Animals (Basel) 2021; 11:ani11061541. [PMID: 34070376 PMCID: PMC8227375 DOI: 10.3390/ani11061541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 05/21/2021] [Accepted: 05/22/2021] [Indexed: 11/19/2022] Open
Abstract
Simple Summary The earth’s magnetic field, celestial cues, and retention of geographical cues en route provide birds with compass knowledge during migration. The magnetic compass works on the direction of the magnetic field, specifically, the course of the field lines. We tested Red-headed Buntings in orientation cages in the evening during spring migration. Simulated overcast testing resulted in a northerly mean direction, while in clear skies, birds oriented in an NNW (north–northwest) direction. Buntings were exposed to 120° anticlockwise shifted magnetic fields under simulated overcast skies and responded by shifting their orientation accordingly. The results showed that this Palaearctic night migrant possesses a magnetic compass, as well as the fact that magnetic cues act as primary directional messengers. When birds were exposed to different environmental conditions at 22 °C and 38 °C temperatures under simulated overcast conditions, they showed a delay in Zugunruhe (migratory restlessness) at 22 °C, while an advance migratory restlessness was observed under 38 °C conditions. Hot and cold weather clearly influenced the timing of migrations in Red-headed Buntings, but not the direction. Abstract Red-headed Buntings (Emberiza bruniceps) perform long-distance migrations within their southerly overwintering grounds and breeding areas in the northern hemisphere. Long-distance migration demands essential orientation mechanisms. The earth’s magnetic field, celestial cues, and memorization of geographical cues en route provide birds with compass knowledge during migration. Birds were tested during spring migration for orientation under natural clear skies, simulated overcast skies at natural day length and temperature, simulated overcast at 22 °C and 38 °C temperatures, and in the deflected (−120°) magnetic field. Under clear skies, the Red-headed Buntings were oriented NNW (north–northwest); simulated overcast testing resulted in a northerly mean direction at local temperatures as well as at 22 °C and 38 °C. The Buntings reacted strongly in favor of the rotated magnetic field under the simulated overcast sky, demonstrating the use of a magnetic compass for migrating in a specific direction.
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9
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Karki N, Vergish S, Zoltowski BD. Cryptochromes: Photochemical and structural insight into magnetoreception. Protein Sci 2021; 30:1521-1534. [PMID: 33993574 DOI: 10.1002/pro.4124] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 05/10/2021] [Accepted: 05/11/2021] [Indexed: 12/21/2022]
Abstract
Cryptochromes (CRYs) function as blue light photoreceptors in diverse physiological processes in nearly all kingdoms of life. Over the past several decades, they have emerged as the most likely candidates for light-dependent magnetoreception in animals, however, a long history of conflicts between in vitro photochemistry and in vivo behavioral data complicate validation of CRYs as a magnetosensor. In this review, we highlight the origins of conflicts regarding CRY photochemistry and signal transduction, and identify recent data that provides clarity on potential mechanisms of signal transduction in magnetoreception. The review primarily focuses on examining differences in photochemistry and signal transduction in plant and animal CRYs, and identifies potential modes of convergent evolution within these independent lineages that may identify conserved signaling pathways.
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Affiliation(s)
- Nischal Karki
- Department of Chemistry, Southern Methodist University, Dallas, Texas, USA
| | - Satyam Vergish
- Department of Chemistry, Southern Methodist University, Dallas, Texas, USA
| | - Brian D Zoltowski
- Department of Chemistry, Southern Methodist University, Dallas, Texas, USA
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10
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Abstract
Species throughout the animal kingdom use the Earth's magnetic field (MF) to navigate using either or both of two mechanisms. The first relies on magnetite crystals in tissue where their magnetic moments align with the MF to transduce a signal transmitted to the central nervous system. The second and the subject of this paper involves cryptochrome (CRY) proteins located in cone photoreceptors distributed across the retina, studied most extensively in birds. According to the "Radical Pair Mechanism" (RPM), blue/UV light excites CRY's flavin cofactor (FAD) to generate radical pairs whose singlet-to-triplet interconversion rate is modulated by an external MF. The signaling product of the RPM produces an impression of the field across the retinal surface. In birds, the resulting signal on the optic nerve is transmitted along the thalamofugal pathway to the primary visual cortex, which projects to brain regions concerned with image processing, memory, and executive function. The net result is a bird's orientation to the MF's inclination: its vector angle relative to the Earth's surface. The quality of ambient light (e.g., polarization) provides additional input to the compass. In birds, the Type IV CRY isoform appears pivotal to the compass, given its positioning within retinal cones; a cytosolic location therein indicating no role in the circadian clock; relatively steady diurnal levels (unlike Type II CRY's cycling); and a full complement of FAD (essential for photosensitivity). The evidence indicates that mammalian Type II CRY isoforms play a light-independent role in the cellular molecular clock without a photoreceptive function.
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Affiliation(s)
| | - Joseph Brain
- Environmental Physiology, Molecular, and Integrative Physiological Sciences Program, Department of Environmental Health, Harvard T. H. Chan School of Public Health, Boston, Massachusetts
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11
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van Hasselt SJ, Mekenkamp GJ, Komdeur J, Allocca G, Vyssotski AL, Piersma T, Rattenborg NC, Meerlo P. Seasonal variation in sleep homeostasis in migratory geese: a rebound of NREM sleep following sleep deprivation in summer but not in winter. Sleep 2021; 44:zsaa244. [PMID: 33220057 PMCID: PMC8033462 DOI: 10.1093/sleep/zsaa244] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Revised: 10/19/2020] [Indexed: 11/24/2022] Open
Abstract
Sleep is a behavioral and physiological state that is thought to serve important functions. Many animals go through phases in the annual cycle where sleep time might be limited, for example, during the migration and breeding phases. This leads to the question whether there are seasonal changes in sleep homeostasis. Using electroencephalogram (EEG) data loggers, we measured sleep in summer and winter in 13 barnacle geese (Branta leucopsis) under semi-natural conditions. During both seasons, we examined the homeostatic regulation of sleep by depriving the birds of sleep for 4 and 8 h after sunset. In winter, barnacle geese showed a clear diurnal rhythm in sleep and wakefulness. In summer, this rhythm was less pronounced, with sleep being spread out over the 24-h cycle. On average, the geese slept 1.5 h less per day in summer compared with winter. In both seasons, the amount of NREM sleep was additionally affected by the lunar cycle, with 2 h NREM sleep less during full moon compared to new moon. During summer, the geese responded to 4 and 8 h of sleep deprivation with a compensatory increase in NREM sleep time. In winter, this homeostatic response was absent. Overall, sleep deprivation only resulted in minor changes in the spectral composition of the sleep EEG. In conclusion, barnacle geese display season-dependent homeostatic regulation of sleep. These results demonstrate that sleep homeostasis is not a rigid phenomenon and suggest that some species may tolerate sleep loss under certain conditions or during certain periods of the year.
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Affiliation(s)
- Sjoerd J van Hasselt
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - Gert-Jan Mekenkamp
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - Jan Komdeur
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
| | - Giancarlo Allocca
- The Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
- School of Biomedical Sciences, University of Melbourne, Parkville, VIC, Australia
- Somnivore Pty. Ltd., Bacchus Marsh, VIC, Australia
| | | | - Theunis Piersma
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
- NIOZ Royal Netherlands Institute for Sea Research, Den Burg, Texel, The Netherlands
| | | | - Peter Meerlo
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen, The Netherlands
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12
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Bolte P, Einwich A, Seth PK, Chetverikova R, Heyers D, Wojahn I, Janssen-Bienhold U, Feederle R, Hore P, Dedek K, Mouritsen H. Cryptochrome 1a localisation in light- and dark-adapted retinae of several migratory and non-migratory bird species: no signs of light-dependent activation. ETHOL ECOL EVOL 2021. [DOI: 10.1080/03949370.2020.1870571] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Petra Bolte
- Institute for Biology and Environmental Sciences, Carl-von-Ossietzky-University Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
| | - Angelika Einwich
- Institute for Biology and Environmental Sciences, Carl-von-Ossietzky-University Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
| | - Pranav K. Seth
- Institute for Biology and Environmental Sciences, Carl-von-Ossietzky-University Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
| | - Raisa Chetverikova
- Institute for Biology and Environmental Sciences, Carl-von-Ossietzky-University Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
| | - Dominik Heyers
- Institute for Biology and Environmental Sciences, Carl-von-Ossietzky-University Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
- Research Centre for Neurosensory Sciences, Carl-von-Ossietzky-University Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
| | - Irina Wojahn
- Institute for Biology and Environmental Sciences, Carl-von-Ossietzky-University Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
| | - Ulrike Janssen-Bienhold
- Research Centre for Neurosensory Sciences, Carl-von-Ossietzky-University Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
- Department of Neuroscience, Carl-von-Ossietzky-University Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
| | - Regina Feederle
- Institute for Diabetes and Obesity, Monoclonal Antibody Core Facility, Helmholtz Zentrum München, German Research Center for Environmental Health, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany
| | - Peter Hore
- Department of Chemistry, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Karin Dedek
- Institute for Biology and Environmental Sciences, Carl-von-Ossietzky-University Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
- Research Centre for Neurosensory Sciences, Carl-von-Ossietzky-University Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
| | - Henrik Mouritsen
- Institute for Biology and Environmental Sciences, Carl-von-Ossietzky-University Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
- Research Centre for Neurosensory Sciences, Carl-von-Ossietzky-University Oldenburg, Carl-von-Ossietzky-Straße 9-11, 26129 Oldenburg, Germany
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13
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Zolotareva A, Utvenko G, Romanova N, Pakhomov A, Chernetsov N. Ontogeny of the star compass in birds: pied flycatchers ( Ficedula hypoleuca) can establish the star compass in spring. J Exp Biol 2021; 224:jeb.237875. [PMID: 33436368 DOI: 10.1242/jeb.237875] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 12/26/2020] [Indexed: 11/20/2022]
Abstract
The star compass of birds, like the sun compass, is not innate. To possess either of them, birds have to observe the rotating sky and determine its centre of rotation (in the case of the star compass) or the sun's movement (for the sun compass). Young birds are believed to learn how to use the star compass before their first migration, even though the evidence of this is lacking. Here, we tested whether hand-raised Pied flycatchers (Ficedula hypoleuca) that had not established the star compass prior to their first autumn migration can gain it later in their ontogeny, in spring. We also attempted to examine whether the observation of diurnal celestial cues (the sun and polarized light) prior to autumn migration would affect the process of star compass learning in spring. When tested in the vertical magnetic field under the natural starry sky, the group of birds that observed the stars in spring as the first celestial cues were able to choose the migratory direction. In contrast, the birds that had never seen the stars were not able to use the nightly celestial cues in the vertical magnetic field. However, birds that had seen the daytime celestial cues till autumn and the stars at spring were disoriented, although this might be due to the small sample size. Our data suggest the possibility that the star compass may be learned in spring and emphasize the necessity for further research into the interaction of celestial compasses.
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Affiliation(s)
- Anna Zolotareva
- Biological Station Rybachy, Zoological Institute, Russian Academy of Sciences, Rybachy 238535, Kaliningrad Region, Russia
| | - Gleb Utvenko
- Moscow State Pedagogical University, 1/1 M. Pirogovskaya St., Moscow 119991, Russia
| | - Nadezhda Romanova
- Moscow State Pedagogical University, 1/1 M. Pirogovskaya St., Moscow 119991, Russia
| | - Alexander Pakhomov
- Biological Station Rybachy, Zoological Institute, Russian Academy of Sciences, Rybachy 238535, Kaliningrad Region, Russia
| | - Nikita Chernetsov
- Biological Station Rybachy, Zoological Institute, Russian Academy of Sciences, Rybachy 238535, Kaliningrad Region, Russia.,Department of Vertebrate Zoology, St Petersburg State University, Universitetskaya Emb. 7/9, St Petersburg 199034, Russia
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14
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Smith MA, Waugh DA, McBurney DL, George JC, Suydam RS, Thewissen JGM, Crish SD. A comparative analysis of cone photoreceptor morphology in bowhead and beluga whales. J Comp Neurol 2020; 529:2376-2390. [PMID: 33377221 DOI: 10.1002/cne.25101] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 12/21/2020] [Accepted: 12/22/2020] [Indexed: 12/30/2022]
Abstract
The cetacean visual system is a product of selection pressures favoring underwater vision, yet relatively little is known about it across taxa. Previous studies report several mutations in the opsin genetic sequence in cetaceans, suggesting the evolutionary complete or partial loss of retinal cone photoreceptor function in mysticete and odontocete lineages, respectively. Despite this, limited anatomical evidence suggests cone structures are partially maintained but with absent outer and inner segments in the bowhead retina. The functional consequence and anatomical distributions associated with these unique cone morphologies remain unclear. The current study further investigates the morphology and distribution of cone photoreceptors in the bowhead whale and beluga retina and evaluates the potential functional capacity of these cells' alternative to photoreception. Refined histological and advanced microscopic techniques revealed two additional cone morphologies in the bowhead and beluga retina that have not been previously described. Two proteins involved in magnetosensation were present in these cone structures suggesting the possibility for an alternative functional role in responding to changes in geomagnetic fields. These findings highlight a revised understanding of the unique evolution of cone and gross retinal anatomy in cetaceans, and provide prefatory evidence of potential functional reassignment of these cells.
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Affiliation(s)
- Matthew A Smith
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, Ohio, USA.,Rebecca D. Considine Research Institute, Akron Children's Hospital, Akron, Ohio, USA
| | - David A Waugh
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, Ohio, USA
| | - Denise L McBurney
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, Ohio, USA
| | - John C George
- Department of Wildlife Management, North Slope Borough, Utqiagvik, Alaska, USA
| | - Robert S Suydam
- Department of Wildlife Management, North Slope Borough, Utqiagvik, Alaska, USA
| | - Johannes G M Thewissen
- Department of Anatomy and Neurobiology, Northeast Ohio Medical University, Rootstown, Ohio, USA
| | - Samuel D Crish
- Department of Pharmaceutical Sciences, Northeast Ohio Medical University, Rootstown, Ohio, USA
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15
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Seewagen CL. The threat of global mercury pollution to bird migration: potential mechanisms and current evidence. ECOTOXICOLOGY (LONDON, ENGLAND) 2020; 29:1254-1267. [PMID: 30159636 DOI: 10.1007/s10646-018-1971-z] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/18/2018] [Indexed: 06/08/2023]
Abstract
Mercury is a global pollutant that has been widely shown to adversely affect reproduction and other endpoints related to fitness and health in birds, but almost nothing is known about its effects on migration relative to other life cycle processes. Here I consider the physiological and histological effects that mercury is known to have on non-migrating birds and non-avian vertebrates to identify potential mechanisms by which mercury might hinder migration performance. I posit that the broad ability of mercury to inactivate enzymes and compromise the function of other proteins is a single mechanism by which mercury has strong potential to disrupt many of the physiological processes that make long-distance migration possible. In just this way alone, there is reason to expect mercury to interfere with navigation, flight endurance, oxidative balance, and stopover refueling. Navigation and flight could be further affected by neurotoxic effects of mercury on the brain regions that process geomagnetic information from the visual system and control biomechanics, respectively. Interference with photochemical reactions in the retina and decreases in scotopic vision sensitivity caused by mercury also have the potential to disrupt visual-based magnetic navigation. Finally, migration performance and possibly survival might be limited by the immunosuppressive effects of mercury on birds at a time when exposure to novel pathogens and parasites is great. I conclude that mercury pollution is likely to be further challenging what is already often the most difficult and perilous phase of a migratory bird's annual cycle, potentially contributing to global declines in migratory bird populations.
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Affiliation(s)
- Chad L Seewagen
- Great Hollow Nature Preserve & Ecological Research Center, 225 Route 37, New Fairfield, CT, USA.
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16
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Caspar KR, Moldenhauer K, Moritz RE, Němec P, Malkemper EP, Begall S. Eyes are essential for magnetoreception in a mammal. J R Soc Interface 2020; 17:20200513. [PMID: 32993431 PMCID: PMC7536053 DOI: 10.1098/rsif.2020.0513] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 09/02/2020] [Indexed: 11/12/2022] Open
Abstract
Several groups of mammals use the Earth's magnetic field for orientation, but their magnetosensory organ remains unknown. The Ansell's mole-rat (Fukomys anselli, Bathyergidae, Rodentia) is a microphthalmic subterranean rodent with innate magnetic orientation behaviour. Previous studies on this species proposed that its magnetoreceptors are located in the eye. To test this hypothesis, we assessed magnetic orientation in mole-rats after the surgical removal of their eyes compared to untreated controls. Initially, we demonstrate that this enucleation does not lead to changes in routine behaviours, including locomotion, feeding and socializing. We then studied magnetic compass orientation by employing a well-established nest-building assay under four magnetic field alignments. In line with previous studies, control animals exhibited a significant preference to build nests in magnetic southeast. By contrast, enucleated mole-rats built nests in random magnetic orientations, suggesting an impairment of their magnetic sense. The results provide robust support for the hypothesis that mole-rats perceive magnetic fields with their minute eyes, probably relying on magnetite-based receptors in the cornea.
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Affiliation(s)
- Kai R. Caspar
- Department of General Zoology, University of Duisburg-Essen, Universitaetsstr. 5, 45117 Essen, Germany
| | - Katrin Moldenhauer
- Department of General Zoology, University of Duisburg-Essen, Universitaetsstr. 5, 45117 Essen, Germany
| | - Regina E. Moritz
- Department of General Zoology, University of Duisburg-Essen, Universitaetsstr. 5, 45117 Essen, Germany
- Department Vision, Visual Impairment & Blindness, Faculty 13, Technical University of Dortmund, Emil-Figge-Straße 50, 44227 Dortmund, Germany
| | - Pavel Němec
- Department of Zoology, Faculty of Science, Charles University, Vinicna 7, 12844 Prague, Czech Republic
| | - E. Pascal Malkemper
- Max Planck Research Group Neurobiology of Magnetoreception, Center of Advanced European Studies and Research (CAESAR), Ludwig-Erhard-Allee 2, 53175 Bonn, Germany
| | - Sabine Begall
- Department of General Zoology, University of Duisburg-Essen, Universitaetsstr. 5, 45117 Essen, Germany
- Department of Game Management and Wildlife Biology, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, 16521 Prague 6, Czech Republic
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17
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Zhou H, Yang S, Chen F. The Magnetic Receptor of Monascus ruber M7: Gene Clone and Its Heterologous Expression in Escherichia coli. Front Microbiol 2020; 11:1112. [PMID: 32636810 PMCID: PMC7318567 DOI: 10.3389/fmicb.2020.01112] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Accepted: 05/04/2020] [Indexed: 01/04/2023] Open
Abstract
It is well known that many organisms can perceive the magnetic field (MF), including the geomagnetic field, but how to feel MF is unclear. Recently, a study has claimed that a biological compass, namely a complex of the magnetic receptor (MagR) and blue light (BL) receptor (cryptochrome), has been found in Homo sapiens, Drosophila melanogaster, and Danaus plexippus, which may bring some new ideas to explore the mechanism of biomagnetism. Monascus spp. are edible filamentous fungi that can produce abundant beneficial secondary metabolites and have been used to produce food colorants for nearly 2000 years in the world, especially in China, Japan, and Korea. In this work, we firstly treated M. ruber M7 by BL (500 lux,465–467 nm), MF (5, 10, 30 mT), and the combination of MF and BL (MF-BL), respectively. The results revealed that, compared with the control (CK, neither BL nor MF), the MF alone had no effect on the growth and morphological characteristics of M7, but BL made the colonial diameters only 66.7% of CK’s and inhibited the formation of cleistothecia. Under MF-BL, the colony diameters were still 66.7% of CK’s, but the colonial growth and cleistothecia production inhibited by BL were partially restored. Then, we have found that the magR gene widely exists in the genomes of animals, plants, and microorganisms, and we have also discovered a magR gene in the M7 genome, hereinafter referred to mr-magR. Finally, the full-length cDNA of mr-magR was successfully cloned and expressed in Escherichia coli BL21 (DE3), and the Mr-MagR protein was purified by a Ni+-NTA column and identified by Western blot. These results have laid a foundation for further investigation on the relationship between Mr-MagR and BL receptor(s) that might exist in M7. According to a literature search, it is the first time to report magR in filamentous fungi.
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Affiliation(s)
- Hongyi Zhou
- Hubei International Scientific and Technological Cooperation Base of Traditional Fermented Foods, Huazhong Agricultural University, Wuhan, China.,College of Food Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Shuyan Yang
- Hubei International Scientific and Technological Cooperation Base of Traditional Fermented Foods, Huazhong Agricultural University, Wuhan, China.,College of Food Science and Technology, Huazhong Agricultural University, Wuhan, China
| | - Fusheng Chen
- Hubei International Scientific and Technological Cooperation Base of Traditional Fermented Foods, Huazhong Agricultural University, Wuhan, China.,College of Food Science and Technology, Huazhong Agricultural University, Wuhan, China
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18
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van Hasselt SJ, Rusche M, Vyssotski AL, Verhulst S, Rattenborg NC, Meerlo P. Sleep Time in the European Starling Is Strongly Affected by Night Length and Moon Phase. Curr Biol 2020; 30:1664-1671.e2. [PMID: 32197088 DOI: 10.1016/j.cub.2020.02.052] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 02/13/2020] [Accepted: 02/18/2020] [Indexed: 12/21/2022]
Abstract
Sleep is considered to be of crucial importance for performance and health, yet much of what we know about sleep is based on studies in a few mammalian model species under strictly controlled laboratory conditions. Data on sleep in different species under more natural conditions may yield new insights in the regulation and functions of sleep. We therefore performed a study with miniature electroencephalogram (EEG) data loggers in starlings under semi-natural conditions, group housed in a large outdoor enclosure with natural temperature and light. The birds showed a striking 5-h difference in the daily amount of non-rapid-eye-movement (NREM) sleep between winter and summer. This variation in the amount of NREM sleep was best explained by night length. Most sleep occurred during the night, but when summer nights became short, the animals displayed mid-day naps. The decay of NREM sleep spectral power in the slow-wave range (1.1-4.3 Hz) was steeper in the short nights than in the longer nights, which suggests that birds in summer have higher sleep pressure. Additionally, sleep was affected by moon phase, with 2 h of NREM sleep less during full moon. The starlings displayed very little rapid-eye-movement (REM) sleep, adding up to 1.3% of total sleep time. In conclusion, this study demonstrates a pronounced phenotypical flexibility in sleep in starlings under semi-natural conditions and shows that environmental factors have a major impact on the organization of sleep and wakefulness.
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Affiliation(s)
- Sjoerd J van Hasselt
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 Groningen, the Netherlands
| | - Maria Rusche
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 Groningen, the Netherlands; Avian Sleep Group, Max Planck Institute for Ornithology, Haus 5, Seewiesen 82319, Germany
| | - Alexei L Vyssotski
- Institute of Neuroinformatics, University of Zurich, Winterthurerstr. 190, 8057 Zurich, Switzerland
| | - Simon Verhulst
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 Groningen, the Netherlands
| | - Niels C Rattenborg
- Avian Sleep Group, Max Planck Institute for Ornithology, Haus 5, Seewiesen 82319, Germany
| | - Peter Meerlo
- Groningen Institute for Evolutionary Life Sciences, University of Groningen, Nijenborgh 7, 9747 Groningen, the Netherlands.
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19
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Bojarinova J, Kavokin K, Pakhomov A, Cherbunin R, Anashina A, Erokhina M, Ershova M, Chernetsov N. Magnetic compass of garden warblers is not affected by oscillating magnetic fields applied to their eyes. Sci Rep 2020; 10:3473. [PMID: 32103061 PMCID: PMC7044251 DOI: 10.1038/s41598-020-60383-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Accepted: 01/31/2020] [Indexed: 11/16/2022] Open
Abstract
The magnetic compass is an important element of the avian navigation system, which allows migratory birds to solve complex tasks of moving between distant breeding and wintering locations. The photochemical magnetoreception in the eye is believed to be the primary biophysical mechanism behind the magnetic sense of birds. It was shown previously that birds were disoriented in presence of weak oscillating magnetic fields (OMF) with frequencies in the megahertz range. The OMF effect was considered to be a fingerprint of the photochemical magnetoreception in the eye. In this work, we used miniaturized portable magnetic coils attached to the bird’s head to specifically target the compass receptor. We performed behavioural experiments on orientation of long-distance migrants, garden warblers (Sylvia borin), in round arenas. The OMF with the amplitude of about 5 nT was applied locally to the birds’ eyes. Surprisingly, the birds were not disoriented and showed the seasonally appropriate migratory direction. On the contrary, the same birds placed in a homogeneous 5 nT OMF generated by large stationary coils showed clear disorientation. On the basis of these findings, we suggest that the disruption of magnetic orientation of birds by oscillating magnetic fields is not related to photochemical magnetoreceptors in their eyes.
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Affiliation(s)
- Julia Bojarinova
- Department Vertebrate Zoology, St. Petersburg State University, 199034, St. Petersburg, Russia. .,Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 194223, St. Petersburg, Russia.
| | - Kirill Kavokin
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 194223, St. Petersburg, Russia.,Spin Optics Lab., St. Petersburg State University, 198504, St. Petersburg, Russia
| | - Alexander Pakhomov
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 194223, St. Petersburg, Russia.,Biological Station Rybachy, Zoological Institute of the Russian Academy of Sciences, 238535, Rybachy, Kaliningrad Region, Russia
| | - Roman Cherbunin
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 194223, St. Petersburg, Russia.,Spin Optics Lab., St. Petersburg State University, 198504, St. Petersburg, Russia
| | - Anna Anashina
- Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 194223, St. Petersburg, Russia.,Biological Station Rybachy, Zoological Institute of the Russian Academy of Sciences, 238535, Rybachy, Kaliningrad Region, Russia
| | - Maria Erokhina
- Department Natural Science and Geography, Ilya Ulyanov State Pedagogical University, 432700, Ulyanovsk, Russia
| | - Maria Ershova
- Department Vertebrate Zoology, Lomonosov Moscow State University, 119234, Moscow, Russia
| | - Nikita Chernetsov
- Department Vertebrate Zoology, St. Petersburg State University, 199034, St. Petersburg, Russia.,Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, 194223, St. Petersburg, Russia.,Biological Station Rybachy, Zoological Institute of the Russian Academy of Sciences, 238535, Rybachy, Kaliningrad Region, Russia
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20
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Beyond Endocasts: Using Predicted Brain-Structure Volumes of Extinct Birds to Assess Neuroanatomical and Behavioral Inferences. DIVERSITY-BASEL 2020. [DOI: 10.3390/d12010034] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The shape of the brain influences skull morphology in birds, and both traits are driven by phylogenetic and functional constraints. Studies on avian cranial and neuroanatomical evolution are strengthened by data on extinct birds, but complete, 3D-preserved vertebrate brains are not known from the fossil record, so brain endocasts often serve as proxies. Recent work on extant birds shows that the Wulst and optic lobe faithfully represent the size of their underlying brain structures, both of which are involved in avian visual pathways. The endocasts of seven extinct birds were generated from microCT scans of their skulls to add to an existing sample of endocasts of extant birds, and the surface areas of their Wulsts and optic lobes were measured. A phylogenetic prediction method based on Bayesian inference was used to calculate the volumes of the brain structures of these extinct birds based on the surface areas of their overlying endocast structures. This analysis resulted in hyperpallium volumes of five of these extinct birds and optic tectum volumes of all seven extinct birds. Phylogenetic ANCOVA (phyANCOVA) were performed on regressions of the brain-structure volumes and endocast structure surface areas on various brain size metrics to determine if the relative sizes of these structures in any extinct birds were significantly different from those of the extant birds in the sample. Phylogenetic ANCOVA indicated that no extinct birds studied had relative hyperpallial volumes that were significantly different from the extant sample, nor were any of their optic tecta relatively hypertrophied. The optic tectum of Dinornis robustus was significantly smaller relative to brain size than any of the extant birds in our sample. This study provides an analytical framework for testing the hypotheses of potential functional behavioral capabilities of other extinct birds based on their endocasts.
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21
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Player TC, Hore PJ. Viability of superoxide-containing radical pairs as magnetoreceptors. J Chem Phys 2020; 151:225101. [PMID: 31837685 DOI: 10.1063/1.5129608] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The ability of night-migratory songbirds to sense the direction of the Earth's magnetic field is increasingly attributed to a photochemical mechanism in which the magnetic field acts on transient radical pairs in cryptochrome flavoproteins located in the birds' eyes. The magnetically sensitive species is commonly assumed to be [FAD•- TrpH•+], formed by sequential light-induced intraprotein electron transfers from a chain of tryptophan residues to the flavin adenine dinucleotide chromophore. However, some evidence points to superoxide, O2 •-, as an alternative partner for the flavin radical. The absence of hyperfine interactions in O2 •- could lead to a more sensitive magnetic compass, but only if the electron spin relaxation of the O2 •- radical is much slower than normally expected for a small mobile radical with an orbitally degenerate electronic ground state. In this study we use spin dynamics simulations to model the sensitivity of a flavin-superoxide radical pair to the direction of a 50 μT magnetic field. By varying parameters that characterize the local environment and molecular dynamics of the radicals, we identify the highly restrictive conditions under which a O2 •--containing radical pair could form the basis of a geomagnetic compass sensor. We conclude that the involvement of superoxide in compass magnetoreception must remain highly speculative until further experimental evidence is forthcoming.
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Affiliation(s)
- Thomas C Player
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford, United Kingdom
| | - P J Hore
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford, United Kingdom
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22
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Bell AM, Robinson JT. The rotating magnetocaloric effect as a potential mechanism for natural magnetic senses. PLoS One 2019; 14:e0222401. [PMID: 31574085 PMCID: PMC6773214 DOI: 10.1371/journal.pone.0222401] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Accepted: 08/28/2019] [Indexed: 12/01/2022] Open
Abstract
Many animals are able to sense the earth’s magnetic field, including varieties of arthropods and members of all major vertebrate groups. While the existence of this magnetic sense is widely accepted, the mechanism of action remains unknown. Building from recent work on synthetic magnetoreceptors, we propose a new model for natural magnetosensation based on the rotating magnetocaloric effect (RME), which predicts that heat generated by magnetic nanoparticles may allow animals to detect features of the earth’s magnetic field. Using this model, we identify the conditions for the RME to produce physiological signals in response to the earth’s magnetic field and suggest experiments to distinguish between candidate mechanisms of magnetoreception.
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Affiliation(s)
- A. Martin Bell
- Applied Physics Program, Rice University, Houston, Texas, United States of America
- Department of Electrical and Computer Engineering, Rice University, Houston, Texas, United States of America
| | - Jacob T. Robinson
- Department of Electrical and Computer Engineering, Rice University, Houston, Texas, United States of America
- Department of Bioengineering, Rice University, Houston, Texas, United States of America
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, United States of America
- * E-mail:
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23
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Zoltowski BD, Chelliah Y, Wickramaratne A, Jarocha L, Karki N, Xu W, Mouritsen H, Hore PJ, Hibbs RE, Green CB, Takahashi JS. Chemical and structural analysis of a photoactive vertebrate cryptochrome from pigeon. Proc Natl Acad Sci U S A 2019; 116:19449-19457. [PMID: 31484780 PMCID: PMC6765304 DOI: 10.1073/pnas.1907875116] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Computational and biochemical studies implicate the blue-light sensor cryptochrome (CRY) as an endogenous light-dependent magnetosensor enabling migratory birds to navigate using the Earth's magnetic field. Validation of such a mechanism has been hampered by the absence of structures of vertebrate CRYs that have functional photochemistry. Here we present crystal structures of Columba livia (pigeon) CRY4 that reveal evolutionarily conserved modifications to a sequence of Trp residues (Trp-triad) required for CRY photoreduction. In ClCRY4, the Trp-triad chain is extended to include a fourth Trp (W369) and a Tyr (Y319) residue at the protein surface that imparts an unusually high quantum yield of photoreduction. These results are consistent with observations of night migratory behavior in animals at low light levels and could have implications for photochemical pathways allowing magnetosensing.
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Affiliation(s)
- Brian D Zoltowski
- Department of Chemistry, Southern Methodist University, Dallas, TX 75275
- Center for Drug Discovery, Design, and Delivery, Southern Methodist University, Dallas, TX 75275
| | - Yogarany Chelliah
- Department of Neuroscience, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Anushka Wickramaratne
- Department of Neuroscience, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Lauren Jarocha
- Department of Chemistry, University of Oxford, OX1 3QZ Oxford, United Kingdom
| | - Nischal Karki
- Department of Chemistry, Southern Methodist University, Dallas, TX 75275
- Center for Drug Discovery, Design, and Delivery, Southern Methodist University, Dallas, TX 75275
| | - Wei Xu
- Department of Neuroscience, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Henrik Mouritsen
- Institute for Biology and Environmental Sciences, Carl von Ossietzky University of Oldenburg, DE-26111 Oldenburg, Germany
- Research Center for Neurosensory Sciences, University of Oldenburg, DE-26111 Oldenburg, Germany
| | - Peter J Hore
- Department of Chemistry, University of Oxford, OX1 3QZ Oxford, United Kingdom
| | - Ryan E Hibbs
- Department of Neuroscience, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Carla B Green
- Department of Neuroscience, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Joseph S Takahashi
- Department of Neuroscience, Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390;
- Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, TX 75390
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24
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Xu JJ, Zhang YC, Wu JQ, Wang WH, Li Y, Wan GJ, Chen FJ, Sword GA, Pan WD. Molecular characterization, spatial-temporal expression and magnetic response patterns of iron-sulfur cluster assembly1 (IscA1) in the rice planthopper, Nilaparvata lugens. INSECT SCIENCE 2019; 26:413-423. [PMID: 29063672 DOI: 10.1111/1744-7917.12546] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2017] [Revised: 09/14/2017] [Accepted: 09/29/2017] [Indexed: 06/07/2023]
Abstract
The mechanisms of magnetoreception have been proposed as the magnetite-based, the chemical radical-pair and biocompass model, in which magnetite particles, the cryptochrome (Cry) or iron-sulfur cluster assembly 1 (IscA1) may be involved. However, little is known about the association among the molecules. Here we investigated the molecular characterization and the mRNA expression of IscA1 in different developmental stages, tissues and magnetic fields in the migratory brown planthopper (BPH), Nilaparvata lugens. NlIscA1 contains an open reading frame of 390 bp, encoding amino acids of 129, with the predicted molecular weight of 14.0 kDa and the isoelectric point of 9.10. Well-conserved Fe-S cluster binding sites were observed in the predicted protein. Phylogenetic analysis demonstrated NlIscA1 to be clustered into the insect's IscA1. NlIscA1 showed up-regulated mRNA expression during the period of migration. The mRNA expression of NlIscA1 could be detected in all the three tissues of head, thorax and abdomen, with the highest expression level in the abdomen. For the macropterous migratory Nilaparvata lugens, mRNA expression of NlIscA1 and N. lugens cryptochrome1 (Nlcry1) were up-regulated under the magnetic fields of 5 Gauss and 10 Gauss in strength (vs. local geomagnetic field), while N. lugens cryptochrome2 (Nlcry2) remained stable. For the brachyterous non-migratory Nilaparvata lugens, no significant changes were found in mRNA expression of NlIscA1, Nlcry1 and Nlcry2 among different magnetic fields. These findings preliminarily reveal that the expression of NlIscA1 and Nlcry1 exhibited coordinated responses to the magnetic field. It suggests some potential associations among the putative magneto-sensitive molecules of cryptochrome and iron-sulfur cluster assembly.
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Affiliation(s)
- Jing-Jing Xu
- Beijing Key Laboratory of Bioelectromagnetics, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Ying-Chao Zhang
- Beijing Key Laboratory of Bioelectromagnetics, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jian-Qi Wu
- Beijing Key Laboratory of Bioelectromagnetics, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Wei-Hong Wang
- Beijing Key Laboratory of Bioelectromagnetics, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yue Li
- Beijing Key Laboratory of Bioelectromagnetics, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing, China
| | - Gui-Jun Wan
- Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Fa-Jun Chen
- Department of Entomology, College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Gregory A Sword
- Department of Entomology, Texas A&M University, College Station, TX, USA
| | - Wei-Dong Pan
- Beijing Key Laboratory of Bioelectromagnetics, Institute of Electrical Engineering, Chinese Academy of Sciences, Beijing, China
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Pooam M, Arthaut LD, Burdick D, Link J, Martino CF, Ahmad M. Magnetic sensitivity mediated by the Arabidopsis blue-light receptor cryptochrome occurs during flavin reoxidation in the dark. PLANTA 2019; 249:319-332. [PMID: 30194534 DOI: 10.1007/s00425-018-3002-y] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2018] [Accepted: 08/29/2018] [Indexed: 05/20/2023]
Abstract
Arabidopsis cryptochrome mediates responses to magnetic fields that have been applied in the absence of light, consistent with flavin reoxidation as the primary detection mechanism. Cryptochromes are highly conserved blue-light-absorbing flavoproteins which have been linked to the perception of electromagnetic stimuli in numerous organisms. These include sensing the direction of the earth's magnetic field in migratory birds and the intensity of magnetic fields in insects and plants. When exposed to light, cryptochromes undergo flavin reduction/reoxidation redox cycles leading to biological activation which generate radical pairs thought to be the basis for magnetic sensitivity. However, the nature of the magnetically sensitive radical pairs and the steps at which they act during the cryptochrome redox cycle are currently a matter of debate. Here, we investigate the response of Arabidopsis cryptochrome-1 in vivo to a static magnetic field of 500 μT (10 × earth's field) using both plant growth and light-dependent phosphorylation as an assay. Cryptochrome responses to light were enhanced by the magnetic field, as indicated by increased inhibition of hypocotyl elongation and increased cryptochrome phosphorylation. However, when light and dark intervals were given intermittently, a plant response to the magnetic field was observed even when the magnetic field was given exclusively during the dark intervals between light exposures. This indicates that the magnetically sensitive reaction step in the cryptochrome photocycle must occur during flavin reoxidation, and likely involves the formation of reactive oxygen species.
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Affiliation(s)
- Marootpong Pooam
- Sorbonne Universités, CNRS, UMR8256, IBPS, Photobiology Research Group, 7 Quai St. Bernard, 75005, Paris, France
| | - Louis-David Arthaut
- Sorbonne Universités, CNRS, UMR8256, IBPS, Photobiology Research Group, 7 Quai St. Bernard, 75005, Paris, France
| | - Derek Burdick
- Sorbonne Universités, CNRS, UMR8256, IBPS, Photobiology Research Group, 7 Quai St. Bernard, 75005, Paris, France
- Xavier University, 3800 Victory Parkway, Cincinnati, OH, 45207, USA
| | - Justin Link
- Xavier University, 3800 Victory Parkway, Cincinnati, OH, 45207, USA
| | - Carlos F Martino
- Department of Biomedical Engineering, Florida Institute of Technology, 150W University Blvd, Melbourne, FL, 32901, USA
| | - Margaret Ahmad
- Sorbonne Universités, CNRS, UMR8256, IBPS, Photobiology Research Group, 7 Quai St. Bernard, 75005, Paris, France.
- Xavier University, 3800 Victory Parkway, Cincinnati, OH, 45207, USA.
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Chang H, Guo JL, Fu XW, Wang ML, Hou YM, Wu KM. Molecular Characterization and Expression Profiles of Cryptochrome Genes in a Long-Distance Migrant, Agrotis segetum (Lepidoptera: Noctuidae). JOURNAL OF INSECT SCIENCE (ONLINE) 2019; 19:5299137. [PMID: 30690535 PMCID: PMC6342827 DOI: 10.1093/jisesa/iey127] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Indexed: 06/09/2023]
Abstract
Cryptochromes act as photoreceptors or integral components of the circadian clock that involved in the regulation of circadian clock and regulation of migratory activity in many animals, and they may also act as magnetoreceptors that sensed the direction of the Earth's magnetic field for the purpose of navigation during animals' migration. Light is a major environmental signal for insect circadian rhythms, and it is also necessary for magnetic orientation. We identified the full-length cDNA encoding As-CRY1 and As-CRY2 in Agrotis segetum Denis and Schiffermaller (turnip moth (Lepidoptera: Noctuidae)). The DNA photolyase domain and flavin adenine dinucleotide-binding domain were found in both cry genes, and multiple alignments showed that those domains that are important for the circadian clock and magnetosensing were highly conserved among different animals. Quantitative polymerase chain reaction showed that cry genes were expressed in all examined body parts, with higher expression in adults during the developmental stages of the moths. Under a 14:10 (L:D) h cycle, the expression of cry genes showed a daily biological rhythm, and light can affect the expression levels of As-cry genes. The expression levels of cry genes were higher in the migratory population than in the reared population and higher in the emigration population than in the immigration population. These findings suggest that the two cryptochrome genes characterized in the turnip moth might be associated with the circadian clock and magnetosensing. Their functions deserve further study, especially for potential control of the turnip moth.
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Affiliation(s)
- Hong Chang
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops and Fujian Province Key Laboratory of Insect Ecology, Fujian Agriculture and Forestry University, Fuzhou, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jiang-Long Guo
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- College of Plant Protection, Shenyang Agricultural University, Shenyang, China
| | - Xiao-Wei Fu
- Department of Plant Protection, Henan Institute of Science and Technology, Xinxiang, China
| | - Meng-Lun Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- Department of Entomology, China Agricultural University, Beijing, China
| | - You-Ming Hou
- State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops and Fujian Province Key Laboratory of Insect Ecology, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Kong-Ming Wu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
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Worster SB, Hore PJ. Proposal to use superparamagnetic nanoparticles to test the role of cryptochrome in magnetoreception. J R Soc Interface 2018; 15:20180587. [PMID: 30381345 PMCID: PMC6228473 DOI: 10.1098/rsif.2018.0587] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 10/08/2018] [Indexed: 11/12/2022] Open
Abstract
Evidence is accumulating to support the hypothesis that some animals use light-induced radical pairs to detect the direction of the Earth's magnetic field. Cryptochrome proteins seem to be involved in the sensory pathway but it is not yet clear if they are the magnetic sensors: they could, instead, play a non-magnetic role as signal transducers downstream of the primary sensor. Here we propose an experiment with the potential to distinguish these functions. The principle is to use superparamagnetic nanoparticles to disable any magnetic sensing role by enhancing the electron spin relaxation of the radicals so as to destroy their spin correlation. We use spin dynamics simulations to show that magnetoferritin, a synthetic, protein-based nanoparticle, has the required properties. If cryptochrome is the primary sensor, then it should be inactivated by a magnetoferritin particle placed 12-16 nm away. This would prevent a bird from using its magnetic compass in behavioural tests and abolish magnetically sensitive neuronal firing in the retina. The key advantage of such an experiment is that any signal transduction role should be completely unaffected by the tiny magnetic interactions (≪kBT) required to enhance the spin relaxation of the radical pair.
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Affiliation(s)
- Susannah Bourne Worster
- Department of Chemistry, University of Oxford, Physical and Theoretical Chemistry Laboratory, South Parks Road, Oxford OX1 3QZ, UK
| | - P J Hore
- Department of Chemistry, University of Oxford, Physical and Theoretical Chemistry Laboratory, South Parks Road, Oxford OX1 3QZ, UK
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Abstract
Over the last three decades, evidence has emerged that low-intensity magnetic fields can influence biological systems. It is now well established that migratory birds have the capacity to detect the Earth's magnetic field; it has been reported that power lines are associated with childhood leukemia and that pulsed magnetic fields increase the production of reactive oxidative species (ROS) in cellular systems. Justifiably, studies in this field have been viewed with skepticism, as the underlying molecular mechanisms are unknown. In the accompanying paper, Sherrard and colleagues report that low-flux pulsed electromagnetic fields (PEMFs) result in aversive behavior in Drosophila larvae and ROS production in cell culture. They further report that these responses require the presence of cryptochrome, a putative magnetoreceptor. If correct, it is conceivable that carcinogenesis associated with power lines, PEMF-induced ROS generation, and animal magnetoreception share a common mechanistic basis.
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Affiliation(s)
- Lukas Landler
- Research Institute of Molecular Pathology, Vienna Biocentre, Vienna, Austria
| | - David A. Keays
- Research Institute of Molecular Pathology, Vienna Biocentre, Vienna, Austria
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Engels S, Treiber CD, Salzer MC, Michalik A, Ushakova L, Keays DA, Mouritsen H, Heyers D. Lidocaine is a nocebo treatment for trigeminally mediated magnetic orientation in birds. J R Soc Interface 2018; 15:20180124. [PMID: 30089685 PMCID: PMC6127160 DOI: 10.1098/rsif.2018.0124] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 07/13/2018] [Indexed: 12/30/2022] Open
Abstract
Even though previously described iron-containing structures in the upper beak of pigeons were almost certainly macrophages, not magnetosensitive neurons, behavioural and neurobiological evidence still supports the involvement of the ophthalmic branch of the trigeminal nerve (V1) in magnetoreception. In previous behavioural studies, inactivation of putative V1-associated magnetoreceptors involved either application of the surface anaesthetic lidocaine to the upper beak or sectioning of V1. Here, we compared the effects of lidocaine treatment, V1 ablations and sham ablations on magnetic field-driven neuronal activation in V1-recipient brain regions in European robins. V1 sectioning led to significantly fewer Egr-1-expressing neurons in the trigeminal brainstem than in the sham-ablated birds, whereas lidocaine treatment had no effect on neuronal activation. Furthermore, Prussian blue staining showed that nearly all iron-containing cells in the subepidermal layer of the upper beak are nucleated and are thus not part of the trigeminal nerve, and iron-containing cells appeared in highly variable numbers at inconsistent locations between individual robins and showed no systematic colocalization with a neuronal marker. Our data suggest that lidocaine treatment has been a nocebo to the birds and a placebo for the experimenters. Currently, the nature and location of any V1-associated magnetosensor remains elusive.
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Affiliation(s)
- Svenja Engels
- AG Neurosensorics, University of Oldenburg, Oldenburg, Germany
- Research Centre for Neurosensory Sciences, University of Oldenburg, Oldenburg, Germany
| | | | | | - Andreas Michalik
- AG Neurosensorics, University of Oldenburg, Oldenburg, Germany
- Research Centre for Neurosensory Sciences, University of Oldenburg, Oldenburg, Germany
| | | | | | - Henrik Mouritsen
- AG Neurosensorics, University of Oldenburg, Oldenburg, Germany
- Research Centre for Neurosensory Sciences, University of Oldenburg, Oldenburg, Germany
| | - Dominik Heyers
- AG Neurosensorics, University of Oldenburg, Oldenburg, Germany
- Research Centre for Neurosensory Sciences, University of Oldenburg, Oldenburg, Germany
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Nielsen C, Nørby MS, Kongsted J, Solov'yov IA. Absorption Spectra of FAD Embedded in Cryptochromes. J Phys Chem Lett 2018; 9:3618-3623. [PMID: 29905481 DOI: 10.1021/acs.jpclett.8b01528] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The magnetic compass sense utilized by migratory birds for long-distance navigation functions only once light of a certain wavelength is present. This piece of evidence fits partially with the popular hypothesis of chemical magnetoreception in cryptochrome proteins, located in the bird retina. According to this hypothesis a magnetosensitive radical pair is produced after photoexcitation of an FAD cofactor inside cryptochrome, and as such the absorption properties of FAD are of crucial importance for cryptochrome activation. However, we reveal that absorption spectra of FAD show very little variation between six different cryptochromes, suggesting that the electronic transitions are barely affected by the chemical differences in the proteins. This conclusion hints on the presence of a secondary photoreceptor or cofactor that could be necessary to explain green-light-activated magnetoreception in birds.
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Affiliation(s)
- Claus Nielsen
- Department of Physics, Chemistry and Pharmacy , University of Southern Denmark , DK-5230 Odense M , Denmark
| | - Morten S Nørby
- Department of Physics, Chemistry and Pharmacy , University of Southern Denmark , DK-5230 Odense M , Denmark
| | - Jacob Kongsted
- Department of Physics, Chemistry and Pharmacy , University of Southern Denmark , DK-5230 Odense M , Denmark
| | - Ilia A Solov'yov
- Department of Physics, Chemistry and Pharmacy , University of Southern Denmark , DK-5230 Odense M , Denmark
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31
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Slaby P, Bartos P, Karas J, Netusil R, Tomanova K, Vacha M. How Swift Is Cry-Mediated Magnetoreception? Conditioning in an American Cockroach Shows Sub-second Response. Front Behav Neurosci 2018; 12:107. [PMID: 29892217 PMCID: PMC5985609 DOI: 10.3389/fnbeh.2018.00107] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 05/07/2018] [Indexed: 11/30/2022] Open
Abstract
Diverse animal species perceive Earth’s magnetism and use their magnetic sense to orientate and navigate. Even non-migrating insects such as fruit flies and cockroaches have been shown to exploit the flavoprotein Cryptochrome (Cry) as a likely magnetic direction sensor; however, the transduction mechanism remains unknown. In order to work as a system to steer insect flight or control locomotion, the magnetic sense must transmit the signal from the receptor cells to the brain at a similar speed to other sensory systems, presumably within hundreds of milliseconds or less. So far, no electrophysiological or behavioral study has tackled the problem of the transduction delay in case of Cry-mediated magnetoreception specifically. Here, using a novel aversive conditioning assay on an American cockroach, we show that magnetic transduction is executed within a sub-second time span. A series of inter-stimulus intervals between conditioned stimuli (magnetic North rotation) and unconditioned aversive stimuli (hot air flow) provides original evidence that Cry-mediated magnetic transduction is sufficiently rapid to mediate insect orientation.
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Affiliation(s)
- Pavel Slaby
- Faculty of Science, Institute of Experimental Biology, Masaryk University, Brno, Czechia
| | - Premysl Bartos
- Faculty of Science, Institute of Experimental Biology, Masaryk University, Brno, Czechia
| | - Jakub Karas
- Faculty of Science, Institute of Experimental Biology, Masaryk University, Brno, Czechia
| | - Radek Netusil
- Faculty of Science, Institute of Experimental Biology, Masaryk University, Brno, Czechia
| | - Kateřina Tomanova
- Faculty of Science, Institute of Experimental Biology, Masaryk University, Brno, Czechia
| | - Martin Vacha
- Faculty of Science, Institute of Experimental Biology, Masaryk University, Brno, Czechia
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32
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La Sorte FA, Fink D, Buler JJ, Farnsworth A, Cabrera-Cruz SA. Seasonal associations with urban light pollution for nocturnally migrating bird populations. GLOBAL CHANGE BIOLOGY 2017; 23:4609-4619. [PMID: 28695706 DOI: 10.1111/gcb.13792] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 06/03/2017] [Indexed: 06/07/2023]
Abstract
The spatial extent and intensity of artificial light at night (ALAN) has increased worldwide through the growth of urban environments. There is evidence that nocturnally migrating birds are attracted to ALAN, and there is evidence that nocturnally migrating bird populations are more likely to occur in urban areas during migration, especially in the autumn. Here, we test if urban sources of ALAN are responsible, at least in part, for these observed urban associations. We use weekly estimates of diurnal occurrence and relative abundance for 40 nocturnally migrating bird species that breed in forested environments in North America to assess how associations with distance to urban areas and ALAN are defined across the annual cycle. Migratory bird populations presented stronger than expected associations with shorter distances to urban areas during migration, and stronger than expected association with higher levels of ALAN outside and especially within urban areas during migration. These patterns were more pronounced during autumn migration, especially within urban areas. Outside of the two migration periods, migratory bird populations presented stronger than expected associations with longer distances to urban areas, especially during the nonbreeding season, and weaker than expected associations with the highest levels of ALAN outside and especially within urban areas. These findings suggest that ALAN is associated with higher levels of diurnal abundance along the boundaries and within the interior of urban areas during migration, especially in the autumn when juveniles are undertaking their first migration journey. These findings support the conclusion that urban sources of ALAN can broadly effect migratory behavior, emphasizing the need to better understand the implications of ALAN for migratory bird populations.
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Affiliation(s)
- Frank A La Sorte
- Cornell Laboratory of Ornithology, Cornell University, Ithaca, NY, USA
| | - Daniel Fink
- Cornell Laboratory of Ornithology, Cornell University, Ithaca, NY, USA
| | - Jeffrey J Buler
- Department of Entomology and Wildlife Ecology, University of Delaware, Newark, DE, USA
| | - Andrew Farnsworth
- Cornell Laboratory of Ornithology, Cornell University, Ithaca, NY, USA
| | - Sergio A Cabrera-Cruz
- Department of Entomology and Wildlife Ecology, University of Delaware, Newark, DE, USA
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33
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Taylor BK. Bioinspired magnetic reception and multimodal sensing. BIOLOGICAL CYBERNETICS 2017; 111:287-308. [PMID: 28660347 DOI: 10.1007/s00422-017-0720-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 05/30/2017] [Indexed: 06/07/2023]
Abstract
Several animals use Earth's magnetic field in concert with other sensor modes to accomplish navigational tasks ranging from local homing to continental scale migration. However, despite extensive research, animal magnetic reception remains poorly understood. Similarly, the Earth's magnetic field offers a signal that engineered systems can leverage to navigate in environments where man-made positioning systems such as GPS are either unavailable or unreliable. This work uses a behavioral strategy inspired by the migratory behavior of sea turtles to locate a magnetic goal and respond to wind when it is present. Sensing is performed using a number of distributed sensors. Based on existing theoretical biology considerations, data processing is performed using combinations of circles and ellipses to exploit the distributed sensing paradigm. Agent-based simulation results indicate that this approach is capable of using two separate magnetic properties to locate a goal from a variety of initial conditions in both noiseless and noisy sensory environments. The system's ability to locate the goal appears robust to noise at the cost of overall path length.
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Affiliation(s)
- Brian K Taylor
- Air Force Research Laboratory - Munitions Directorate, 101 West Eglin Blvd Ste. 209, Bldg 13, Eglin AFB, FL, 32542, USA.
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Pakhomov A, Bojarinova J, Cherbunin R, Chetverikova R, Grigoryev PS, Kavokin K, Kobylkov D, Lubkovskaja R, Chernetsov N. Very weak oscillating magnetic field disrupts the magnetic compass of songbird migrants. J R Soc Interface 2017; 14:20170364. [PMID: 28794163 PMCID: PMC5582129 DOI: 10.1098/rsif.2017.0364] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 07/13/2017] [Indexed: 11/12/2022] Open
Abstract
Previously, it has been shown that long-distance migrants, garden warblers (Sylvia borin), were disoriented in the presence of narrow-band oscillating magnetic field (1.403 MHz OMF, 190 nT) during autumn migration. This agrees with the data of previous experiments with European robins (Erithacus rubecula). In this study, we report the results of experiments with garden warblers tested under a 1.403 MHz OMF with various amplitudes (∼0.4, 1, ∼2.4, 7 and 20 nT). We found that the ability of garden warblers to orient in round arenas using the magnetic compass could be disrupted by a very weak oscillating field, such as an approximate 2.4, 7 and 20 nT OMF, but not by an OMF with an approximate 0.4 nT amplitude. The results of the present study indicate that the sensitivity threshold of the magnetic compass to the OMF lies around 2-3 nT, while in experiments with European robins the birds were disoriented in a 15 nT OMF but could choose the appropriate migratory direction when a 5 nT OMF was added to the stationary magnetic field. The radical-pair model, one of the mainstream theories of avian magnetoreception, cannot explain the sensitivity to such a low-intensity OMF, and therefore, it needs further refinement.
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Affiliation(s)
- Alexander Pakhomov
- Biological Station Rybachy, Zoological Institute RAS, 238535 Rybachy, Kaliningrad Region, Russia
- Sechenov Institute of Evolutionary Physiology and Biochemistry, 44 Thorez Ave, 194223 St Petersburg, Russia
| | - Julia Bojarinova
- Sechenov Institute of Evolutionary Physiology and Biochemistry, 44 Thorez Ave, 194223 St Petersburg, Russia
- St Petersburg State University, 7-9 Universitetskaya Emb., St Petersburg 199034, Russia
| | - Roman Cherbunin
- Sechenov Institute of Evolutionary Physiology and Biochemistry, 44 Thorez Ave, 194223 St Petersburg, Russia
- St Petersburg State University, 7-9 Universitetskaya Emb., St Petersburg 199034, Russia
| | - Raisa Chetverikova
- St Petersburg State University, 7-9 Universitetskaya Emb., St Petersburg 199034, Russia
- AG Neurosensorik (Animal Navigation), Institut für Biologie und Umweltwissenschaften (IBU), University of Oldenburg, 26111 Oldenburg, Germany
| | - Philipp S Grigoryev
- St Petersburg State University, 7-9 Universitetskaya Emb., St Petersburg 199034, Russia
| | - Kirill Kavokin
- Sechenov Institute of Evolutionary Physiology and Biochemistry, 44 Thorez Ave, 194223 St Petersburg, Russia
- St Petersburg State University, 7-9 Universitetskaya Emb., St Petersburg 199034, Russia
- A.F. Ioffe Physical Technical Institute, 26 Polytechnicheskaya, St Petersburg 194021, Russia
| | - Dmitry Kobylkov
- AG Neurosensorik (Animal Navigation), Institut für Biologie und Umweltwissenschaften (IBU), University of Oldenburg, 26111 Oldenburg, Germany
| | - Regina Lubkovskaja
- St Petersburg State University, 7-9 Universitetskaya Emb., St Petersburg 199034, Russia
| | - Nikita Chernetsov
- Biological Station Rybachy, Zoological Institute RAS, 238535 Rybachy, Kaliningrad Region, Russia
- Sechenov Institute of Evolutionary Physiology and Biochemistry, 44 Thorez Ave, 194223 St Petersburg, Russia
- St Petersburg State University, 7-9 Universitetskaya Emb., St Petersburg 199034, Russia
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35
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Krylov VV. Biological effects related to geomagnetic activity and possible mechanisms. Bioelectromagnetics 2017. [DOI: 10.1002/bem.22062] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Viacheslav V. Krylov
- I.D. Papanin Institute for Biology of Inland Waters Russian Academy of Sciences; Borok Russian Federation
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36
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Taylor BK, Johnsen S, Lohmann KJ. Detection of magnetic field properties using distributed sensing: a computational neuroscience approach. BIOINSPIRATION & BIOMIMETICS 2017; 12:036013. [PMID: 28524068 DOI: 10.1088/1748-3190/aa6ccd] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Diverse taxa use Earth's magnetic field to aid both short- and long-distance navigation. Study of these behaviors has led to a variety of postulated sensory and processing mechanisms that remain unconfirmed. Although several models have been proposed to explain and understand these mechanisms' underpinnings, they have not necessarily connected a putative sensory signal to the nervous system. Using mathematical software simulation, hardware testing and the computational neuroscience tool of dynamic neural fields, the present work implements a previously developed conceptual model for processing magnetite-based magnetosensory data. Results show that the conceptual model, originally constructed to stimulate thought and generate insights into future physiological experiments, may provide a valid approach to encoding magnetic field information. Specifically, magnetoreceptors that are each individually capable of sensing directional information can, as a population, encode magnetic intensity and direction. The findings hold promise both as a biological magnetoreception concept and for generating engineering innovations in sensing and processing.
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Affiliation(s)
- Brian K Taylor
- Integrated Sensing and Processing Sciences, Air Force Research Laboratory-Munitions Directorate, Eglin Air Force Base, Florida, United States of America. Author to whom any correspondence should be addressed
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Pinzon-Rodriguez A, Muheim R. Zebra finches have a light-dependent magnetic compass similar to migratory birds. J Exp Biol 2017; 220:1202-1209. [DOI: 10.1242/jeb.148098] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 01/10/2017] [Indexed: 12/24/2022]
Abstract
ABSTRACT
Birds have a light-dependent magnetic compass that provides information about the spatial alignment of the geomagnetic field. It is proposed to be located in the avian retina and mediated by a light-induced, radical-pair mechanism involving cryptochromes as sensory receptor molecules. To investigate how the behavioural responses of birds under different light spectra match with cryptochromes as the primary magnetoreceptor, we examined the spectral properties of the magnetic compass in zebra finches. We trained birds to relocate a food reward in a spatial orientation task using magnetic compass cues. The birds were well oriented along the trained magnetic compass axis when trained and tested under low-irradiance 521 nm green light. In the presence of a 1.4 MHz radio-frequency electromagnetic (RF)-field, the birds were disoriented, which supports the involvement of radical-pair reactions in the primary magnetoreception process. Birds trained and tested under 638 nm red light showed a weak tendency to orient ∼45 deg clockwise of the trained magnetic direction. Under low-irradiance 460 nm blue light, they tended to orient along the trained magnetic compass axis, but were disoriented under higher irradiance light. Zebra finches trained and tested under high-irradiance 430 nm indigo light were well oriented along the trained magnetic compass axis, but disoriented in the presence of a RF-field. We conclude that magnetic compass responses of zebra finches are similar to those observed in nocturnally migrating birds and agree with cryptochromes as the primary magnetoreceptor, suggesting that light-dependent, radical-pair-mediated magnetoreception is a common property for all birds, including non-migratory species.
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Affiliation(s)
| | - Rachel Muheim
- Department of Biology, Lund University, Biology Building B, Lund 223 62, Sweden
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Magnetic activation in the brain of the migratory northern wheatear (Oenanthe oenanthe). J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2017; 203:591-600. [DOI: 10.1007/s00359-017-1167-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 03/16/2017] [Accepted: 03/19/2017] [Indexed: 10/19/2022]
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Kavokin K. Can a hybrid chemical-ferromagnetic model of the avian compass explain its outstanding sensitivity to magnetic noise? PLoS One 2017; 12:e0173887. [PMID: 28296939 PMCID: PMC5352016 DOI: 10.1371/journal.pone.0173887] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2016] [Accepted: 02/28/2017] [Indexed: 11/30/2022] Open
Abstract
While many properties of the magnetic compass of migratory birds are satisfactory explained within the chemical model of magnetoreception, its extreme sensitivity to radio-frequency magnetic fields remains a mystery. Apparently, this difficulty could be overcome if the magnetoreceptor model were augmented with a magnetite nanoparticle, which would amplify the magnetic field at the position of the magneto-sensitive cryptochrome molecule. However, comparison of the radio-frequency power used in the experiment with intrinsic magnetization noise of such a particle, estimated from the theory of fluctuations, shows that the required sensitivity cannot be reached with realistic parameters of iron-oxide nanocrystals.
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Affiliation(s)
- Kirill Kavokin
- Spin Optics Laboratory, St. Petersburg State University, St. Petersburg, Russia
- I.M.Sechenov Institute of Evolutionary Physiology and Biochemistry RAS, St. Petersburg, Russia
- * E-mail:
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Höytö A, Herrala M, Luukkonen J, Juutilainen J, Naarala J. Cellular detection of 50 Hz magnetic fields and weak blue light: effects on superoxide levels and genotoxicity. Int J Radiat Biol 2017; 93:646-652. [PMID: 28264623 DOI: 10.1080/09553002.2017.1294275] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PURPOSE We tested the hypothesis that the effects of 50 Hz magnetic fields (MFs) on superoxide levels and genotoxicity depend on the presence of blue light. MATERIALS AND METHODS Human SH-SY5Y neuroblastoma cells were exposed to a 50 Hz, 100 μT MF with or without non-phototoxic level of blue light for 24 h. We also studied whether these treatments alter responses to menadione, an agent that induces mitochondrial superoxide (O2• -) production and DNA damage. Micronuclei, proliferation, viability, cytosolic and mitochondrial O2• - levels were assessed. RESULTS MF (without blue light) increased cytosolic O2• - production and blue light suppressed this effect. Mitochondrial O2• - production was reduced by both MF and blue light, but these effects were not additive. Micronucleus frequency was not affected by blue light or MF alone, but blue light (significantly when combined with MF) enhanced menadione-induced micronuclei. CONCLUSIONS The original simple hypothesis (blue light is needed for MF effects) was not supported, but interaction of MF and blue light was nevertheless observed. The results are consistent with MF effects on light-independent radical reactions.
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Affiliation(s)
- Anne Höytö
- a Department of Environmental and Biological Sciences , University of Eastern Finland , Kuopio , Finland
| | - Mikko Herrala
- a Department of Environmental and Biological Sciences , University of Eastern Finland , Kuopio , Finland
| | - Jukka Luukkonen
- a Department of Environmental and Biological Sciences , University of Eastern Finland , Kuopio , Finland
| | - Jukka Juutilainen
- a Department of Environmental and Biological Sciences , University of Eastern Finland , Kuopio , Finland
| | - Jonne Naarala
- a Department of Environmental and Biological Sciences , University of Eastern Finland , Kuopio , Finland
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42
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Taylor BK. Validating a model for detecting magnetic field intensity using dynamic neural fields. J Theor Biol 2016; 408:53-65. [PMID: 27521527 DOI: 10.1016/j.jtbi.2016.08.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 08/05/2016] [Accepted: 08/10/2016] [Indexed: 11/18/2022]
Abstract
Several animals use properties of Earth's magnetic field as a part of their navigation toolkit to accomplish tasks ranging from local homing to continental migration. Studying these behaviors has led to the postulation of both a magnetite-based sense, and a chemically based radical-pair mechanism. Several researchers have proposed models aimed at both understanding these mechanisms, and offering insights into future physiological experiments. The present work mathematically implements a previously developed conceptual model for sensing and processing magnetite-based magnetosensory feedback by using dynamic neural fields, a computational neuroscience tool for modeling nervous system dynamics and processing. Results demonstrate the plausibility of the conceptual model's predictions. Specifically, a population of magnetoreceptors in which each individual can only sense directional information can encode magnetic intensity en masse. Multiple populations can encode both magnetic direction, and intensity, two parameters that several animals use in their navigational toolkits. This work can be expanded to test other magnetoreceptor models.
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Affiliation(s)
- Brian K Taylor
- Air Force Research Laboratory - Munitions Directorate, 101 West Eglin Blvd, Ste. 209, Bldg 13 Eglin AFB, FL 32542, USA
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43
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Procopio M, Ritz T. Inhomogeneous ensembles of radical pairs in chemical compasses. Sci Rep 2016; 6:35443. [PMID: 27804956 PMCID: PMC5090225 DOI: 10.1038/srep35443] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 09/28/2016] [Indexed: 11/09/2022] Open
Abstract
The biophysical basis for the ability of animals to detect the geomagnetic field and to use it for finding directions remains a mystery of sensory biology. One much debated hypothesis suggests that an ensemble of specialized light-induced radical pair reactions can provide the primary signal for a magnetic compass sensor. The question arises what features of such a radical pair ensemble could be optimized by evolution so as to improve the detection of the direction of weak magnetic fields. Here, we focus on the overlooked aspect of the noise arising from inhomogeneity of copies of biomolecules in a realistic biological environment. Such inhomogeneity leads to variations of the radical pair parameters, thereby deteriorating the signal arising from an ensemble and providing a source of noise. We investigate the effect of variations in hyperfine interactions between different copies of simple radical pairs on the directional response of a compass system. We find that the choice of radical pair parameters greatly influences how strongly the directional response of an ensemble is affected by inhomogeneity.
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Affiliation(s)
- Maria Procopio
- Department of Physics and Astronomy, University of California, Irvine, 92697-4345, USA
| | - Thorsten Ritz
- Department of Physics and Astronomy, University of California, Irvine, 92697-4345, USA
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Mouloudakis K, Kominis IK. Revealing the properties of the radical-pair magnetoreceptor using pulsed photo-excitation timed with pulsed rf. Biosystems 2016; 147:35-9. [PMID: 27450635 DOI: 10.1016/j.biosystems.2016.07.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 06/17/2016] [Accepted: 07/15/2016] [Indexed: 11/17/2022]
Abstract
The radical-pair mechanism is understood to underlie the magnetic navigation capability of birds and possibly other species. Experiments with birds have provided indirect and in cases conflicting evidence on the actual existence of this mechanism. We here propose a new experiment that can unambiguously identify the presence of the radical-pair magnetoreceptor in birds and unravel some of its basic properties. The proposed experiment is based on modulated light excitation with a pulsed laser, combined with delayed radio-frequency magnetic field pulses. We predict a resonance effect in the birds' magnetic orientation versus the rf-pulse delay time. The resonance's position reflects the singlet-triplet mixing time of the magnetoreceptor.
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Affiliation(s)
- K Mouloudakis
- Department of Physics, University of Crete, Heraklion 71003, Greece
| | - I K Kominis
- Department of Physics, University of Crete, Heraklion 71003, Greece.
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Worster S, Kattnig DR, Hore PJ. Spin relaxation of radicals in cryptochrome and its role in avian magnetoreception. J Chem Phys 2016; 145:035104. [DOI: 10.1063/1.4958624] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Affiliation(s)
- Susannah Worster
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Daniel R. Kattnig
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - P. J. Hore
- Department of Chemistry, Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
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46
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Affiliation(s)
- P. J. Hore
- Department of Chemistry, University of Oxford, Oxford OX1 3QZ, United Kingdom;
| | - Henrik Mouritsen
- Institut für Biologie und Umweltwissenschaften, Carl von Ossietzky Universität Oldenburg, DE-26111 Oldenburg, Germany;
- Research Centre for Neurosensory Sciences, University of Oldenburg, DE-26111 Oldenburg, Germany
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Bender M, Mouritsen H, Christoffers J. A robust synthesis of 7,8-didemethyl-8-hydroxy-5-deazariboflavin. Beilstein J Org Chem 2016; 12:912-7. [PMID: 27340481 PMCID: PMC4901869 DOI: 10.3762/bjoc.12.89] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 04/28/2016] [Indexed: 12/13/2022] Open
Abstract
The biosynthetic precursor of redox cofactor F420, 7,8-didemethyl-8-hydroxy-5-deazariboflavin, was prepared in four steps from 6-chlorouracil, 2-chloro-4-hydroxybenzaldehyde and bis-isopropylidene protected D-ribose. The latter aldehyde was transformed to the corresponding protected ribitylamine via the oxime, which was submitted to reduction with LiAlH4. Key advantage compared to previous syntheses is the utilization of a polyol-protective group which allowed the chromatographic purification of a key-intermediate product providing the target compound with high purity.
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Affiliation(s)
- Matthias Bender
- Institut für Chemie, Universität Oldenburg, Carl von Ossietzky-Str. 9-11, D-26129 Oldenburg, Germany
| | - Henrik Mouritsen
- Institut für Biologie und Umweltwissenschaften, Universität Oldenburg, D-26111 Oldenburg, Germany; Centre for Neurosensory Sciences, University of Oldenburg, D-26111 Oldenburg, Germany
| | - Jens Christoffers
- Institut für Chemie, Universität Oldenburg, Carl von Ossietzky-Str. 9-11, D-26129 Oldenburg, Germany
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Hiscock HG, Worster S, Kattnig DR, Steers C, Jin Y, Manolopoulos DE, Mouritsen H, Hore PJ. The quantum needle of the avian magnetic compass. Proc Natl Acad Sci U S A 2016; 113:4634-9. [PMID: 27044102 PMCID: PMC4855607 DOI: 10.1073/pnas.1600341113] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Migratory birds have a light-dependent magnetic compass, the mechanism of which is thought to involve radical pairs formed photochemically in cryptochrome proteins in the retina. Theoretical descriptions of this compass have thus far been unable to account for the high precision with which birds are able to detect the direction of the Earth's magnetic field. Here we use coherent spin dynamics simulations to explore the behavior of realistic models of cryptochrome-based radical pairs. We show that when the spin coherence persists for longer than a few microseconds, the output of the sensor contains a sharp feature, referred to as a spike. The spike arises from avoided crossings of the quantum mechanical spin energy-levels of radicals formed in cryptochromes. Such a feature could deliver a heading precision sufficient to explain the navigational behavior of migratory birds in the wild. Our results (i) afford new insights into radical pair magnetoreception, (ii) suggest ways in which the performance of the compass could have been optimized by evolution, (iii) may provide the beginnings of an explanation for the magnetic disorientation of migratory birds exposed to anthropogenic electromagnetic noise, and (iv) suggest that radical pair magnetoreception may be more of a quantum biology phenomenon than previously realized.
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Affiliation(s)
- Hamish G Hiscock
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
| | - Susannah Worster
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
| | - Daniel R Kattnig
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
| | - Charlotte Steers
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
| | - Ye Jin
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
| | - David E Manolopoulos
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom
| | - Henrik Mouritsen
- Institut für Biologie und Umweltwissenschaften, Carl von Ossietzky Universität Oldenburg, 26111 Oldenburg, Germany; Research Centre for Neurosensory Sciences, University of Oldenburg, 26111 Oldenburg, Germany
| | - P J Hore
- Department of Chemistry, Physical & Theoretical Chemistry Laboratory, University of Oxford, Oxford OX1 3QZ, United Kingdom;
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Malkemper EP, Painter MS, Landler L. Shifted magnetic alignment in vertebrates: Evidence for neural lateralization? J Theor Biol 2016; 399:141-7. [PMID: 27059891 DOI: 10.1016/j.jtbi.2016.03.040] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 03/13/2016] [Accepted: 03/28/2016] [Indexed: 11/15/2022]
Abstract
A wealth of evidence provides support for magnetic alignment (MA) behavior in a variety of disparate species within the animal kingdom, in which an animal, or a group of animals, show a tendency to align the body axis in a consistent orientation relative to the geomagnetic field lines. Interestingly, among vertebrates, MA typically coincides with the north-south magnetic axis, however, the mean directional preferences of an individual or group of organisms is often rotated clockwise from the north-south axis. We hypothesize that this shift is not a coincidence, and future studies of this subtle, yet consistent phenomenon may help to reveal some properties of the underlying sensory or processing mechanisms, that, to date, are not well understood. Furthermore, characterizing the fine structure exhibited in MA behaviors may provide key insights to the biophysical substrates mediating magnetoreception in vertebrates. Therefore, in order to determine if a consistent shift is exhibited in taxonomically diverse vertebrates, we performed a meta-analysis on published MA datasets from 23 vertebrate species that exhibited an axial north-south preference. This analysis revealed a significant clockwise shift from the north-south magnetic axis. We summarize and discuss possible competing hypotheses regarding the proximate mechanisms underlying the clockwise shifted MA and conclude that the most likely cause of such a shift would be a lateralization in central processing of magnetic information.
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Affiliation(s)
- E Pascal Malkemper
- Department of General Zoology, Faculty of Biology, University of Duisburg-Essen, Universitätsstrasse. 2, 45117 Essen, Germany; Department of Game Management and Wildlife Biology, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences Prague, Kamýcká 129, 165 21 Prague 6, Czech Republic
| | - Michael S Painter
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, United States of America
| | - Lukas Landler
- Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, United States of America; Research Institute of Molecular Pathology (IMP), Vienna Biocenter (VBC), 1030 Vienna, Austria.
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50
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Kattnig DR, Solov'yov IA, Hore PJ. Electron spin relaxation in cryptochrome-based magnetoreception. Phys Chem Chem Phys 2016; 18:12443-56. [PMID: 27020113 DOI: 10.1039/c5cp06731f] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The magnetic compass sense of migratory birds is thought to rely on magnetically sensitive radical pairs formed photochemically in cryptochrome proteins in the retina. An important requirement of this hypothesis is that electron spin relaxation is slow enough for the Earth's magnetic field to have a significant effect on the coherent spin dynamics of the radicals. It is generally assumed that evolutionary pressure has led to protection of the electron spins from irreversible loss of coherence in order that the underlying quantum dynamics can survive in a noisy biological environment. Here, we address this question for a structurally characterized model cryptochrome expected to share many properties with the putative avian receptor protein. To this end we combine all-atom molecular dynamics simulations, Bloch-Redfield relaxation theory and spin dynamics calculations to assess the effects of spin relaxation on the performance of the protein as a compass sensor. Both flavin-tryptophan and flavin-Z˙ radical pairs are studied (Z˙ is a radical with no hyperfine interactions). Relaxation is considered to arise from modulation of hyperfine interactions by librational motions of the radicals and fluctuations in certain dihedral angles. For Arabidopsis thaliana cryptochrome 1 (AtCry1) we find that spin relaxation implies optimal radical pair lifetimes of the order of microseconds, and that flavin-Z˙ pairs are less affected by relaxation than flavin-tryptophan pairs. Our results also demonstrate that spin relaxation in isolated AtCry1 is incompatible with the long coherence times that have been postulated to explain the disruption of the avian magnetic compass sense by weak radiofrequency magnetic fields. We conclude that a cryptochrome sensor in vivo would have to differ dynamically, if not structurally, from isolated AtCry1. Our results clearly mark the limits of the current hypothesis and lead to a better understanding of the operation of radical pair magnetic sensors in noisy biological environments.
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Affiliation(s)
- Daniel R Kattnig
- Department of Chemistry, University of Oxford, Physical and Theoretical Chemistry Laboratory, OX1 3QZ, UK.
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