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Sheppard DMW, Li J, Henbest KB, Neil SRT, Maeda K, Storey J, Schleicher E, Biskup T, Rodriguez R, Weber S, Hore PJ, Timmel CR, Mackenzie SR. Millitesla magnetic field effects on the photocycle of an animal cryptochrome. Sci Rep 2017; 7:42228. [PMID: 28176875 PMCID: PMC5296725 DOI: 10.1038/srep42228] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2016] [Accepted: 01/06/2017] [Indexed: 11/09/2022] Open
Abstract
Drosophila have been used as model organisms to explore both the biophysical mechanisms of animal magnetoreception and the possibility that weak, low-frequency anthropogenic electromagnetic fields may have biological consequences. In both cases, the presumed receptor is cryptochrome, a protein thought to be responsible for magnetic compass sensing in migratory birds and a variety of magnetic behavioural responses in insects. Here, we demonstrate that photo-induced electron transfer reactions in Drosophila melanogaster cryptochrome are indeed influenced by magnetic fields of a few millitesla. The form of the protein containing flavin and tryptophan radicals shows kinetics that differ markedly from those of closely related members of the cryptochrome-photolyase family. These differences and the magnetic sensitivity of Drosophila cryptochrome are interpreted in terms of the radical pair mechanism and a photocycle involving the recently discovered fourth tryptophan electron donor.
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Affiliation(s)
- Dean M. W. Sheppard
- Department of Chemistry, University of Oxford, Physical & Theoretical Chemistry Laboratory, Oxford OX1 3QZ, United Kingdom
| | - Jing Li
- Department of Chemistry, University of Oxford, Physical & Theoretical Chemistry Laboratory, Oxford OX1 3QZ, United Kingdom
| | - Kevin B. Henbest
- Department of Chemistry, University of Oxford, Physical & Theoretical Chemistry Laboratory, Oxford OX1 3QZ, United Kingdom
- Department of Chemistry, University of Oxford, Centre for Advanced Electron Spin Resonance, Inorganic Chemistry Laboratory, Oxford OX1 3QR, United Kingdom
| | - Simon R. T. Neil
- Department of Chemistry, University of Oxford, Physical & Theoretical Chemistry Laboratory, Oxford OX1 3QZ, United Kingdom
| | - Kiminori Maeda
- Department of Chemistry, University of Oxford, Centre for Advanced Electron Spin Resonance, Inorganic Chemistry Laboratory, Oxford OX1 3QR, United Kingdom
- Department of Chemistry, Graduate School of Science and Engineering, Saitama University, Saitama, 338-8570, Japan
| | - Jonathan Storey
- Department of Chemistry, University of Oxford, Centre for Advanced Electron Spin Resonance, Inorganic Chemistry Laboratory, Oxford OX1 3QR, United Kingdom
| | - Erik Schleicher
- Institute of Physical Chemistry, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany
| | - Till Biskup
- Institute of Physical Chemistry, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany
| | - Ryan Rodriguez
- Institute of Physical Chemistry, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany
| | - Stefan Weber
- Institute of Physical Chemistry, Albert-Ludwigs-Universität Freiburg, 79104 Freiburg, Germany
| | - P. J. Hore
- Department of Chemistry, University of Oxford, Physical & Theoretical Chemistry Laboratory, Oxford OX1 3QZ, United Kingdom
| | - Christiane R. Timmel
- Department of Chemistry, University of Oxford, Centre for Advanced Electron Spin Resonance, Inorganic Chemistry Laboratory, Oxford OX1 3QR, United Kingdom
| | - Stuart R. Mackenzie
- Department of Chemistry, University of Oxford, Physical & Theoretical Chemistry Laboratory, Oxford OX1 3QZ, United Kingdom
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Kuno S, Kanamori T, Yijing Z, Ohtani H, Yuasa H. Long Persistent Phosphorescence of Crystalline Phenylboronic Acid Derivatives: Photophysics and a Mechanistic Study. CHEMPHOTOCHEM 2017. [DOI: 10.1002/cptc.201600031] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Shinichi Kuno
- School of Life Science and Technology; Tokyo Institute of Technology; J2-10 4259 Nagatsutacho, Midoriku Yokohama 226-8501 Japan
| | - Takashi Kanamori
- School of Life Science and Technology; Tokyo Institute of Technology; J2-10 4259 Nagatsutacho, Midoriku Yokohama 226-8501 Japan
| | - Zhao Yijing
- School of Life Science and Technology; Tokyo Institute of Technology; J2-10 4259 Nagatsutacho, Midoriku Yokohama 226-8501 Japan
| | - Hiroyuki Ohtani
- School of Life Science and Technology; Tokyo Institute of Technology; J2-10 4259 Nagatsutacho, Midoriku Yokohama 226-8501 Japan
| | - Hideya Yuasa
- School of Life Science and Technology; Tokyo Institute of Technology; J2-10 4259 Nagatsutacho, Midoriku Yokohama 226-8501 Japan
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53
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Multiscale description of avian migration: from chemical compass to behaviour modeling. Sci Rep 2016; 6:36709. [PMID: 27830725 PMCID: PMC5103213 DOI: 10.1038/srep36709] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Accepted: 10/19/2016] [Indexed: 11/08/2022] Open
Abstract
Despite decades of research the puzzle of the magnetic sense of migratory songbirds has still not been unveiled. Although the problem really needs a multiscale description, most of the individual research efforts were focused on single scale investigations. Here we seek to establish a multiscale link between some of the scales involved, and in particular construct a bridge between electron spin dynamics and migratory bird behaviour. In order to do that, we first consider a model cyclic reaction scheme that could form the basis of the avian magnetic compass. This reaction features a fast spin-dependent process which leads to an unusually precise compass. We then propose how the reaction could be realized in a realistic molecular environment, and argue that it is consistent with the known facts about avian magnetoreception. Finally we show how the microscopic dynamics of spins could possibly be interpreted by a migrating bird and used for the navigational purpose.
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Migratory blackcaps can use their magnetic compass at 5 degrees inclination, but are completely random at 0 degrees inclination. Sci Rep 2016; 6:33805. [PMID: 27667569 PMCID: PMC5036058 DOI: 10.1038/srep33805] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2016] [Accepted: 08/31/2016] [Indexed: 11/09/2022] Open
Abstract
It is known that night-migratory songbirds use a magnetic compass measuring the magnetic inclination angle, i.e. the angle between the Earth’s surface and the magnetic field lines, but how do such birds orient at the magnetic equator? A previous study reported that birds are completely randomly oriented in a horizontal north-south magnetic field with 0° inclination angle. This seems counter-intuitive, because birds using an inclination compass should be able to separate the north-south axis from the east-west axis, so that bimodal orientation might be expected in a horizontal field. Furthermore, little is known about how shallow inclination angles migratory birds can still use for orientation. In this study, we tested the magnetic compass orientation of night-migratory Eurasian blackcaps (Sylvia atricapilla) in magnetic fields with 5° and 0° inclination. At 5° inclination, the birds oriented as well as they did in the normal 67° inclined field in Oldenburg. In contrast, they were completely randomly oriented in the horizontal field, showing no sign of bimodality. Our results indicate that the inclination limit for the magnetic compass of the blackcap is below 5° and that these birds indeed seem completely unable to use their magnetic compass for orientation in a horizontal magnetic field.
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Evans EW, Kattnig DR, Henbest KB, Hore PJ, Mackenzie SR, Timmel CR. Sub-millitesla magnetic field effects on the recombination reaction of flavin and ascorbic acid radicals. J Chem Phys 2016; 145:085101. [DOI: 10.1063/1.4961266] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Emrys W. Evans
- Department of Chemistry, Centre for Advanced Electron Spin Resonance, University of Oxford, Oxford, United Kingdom
| | - Daniel R. Kattnig
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford, United Kingdom
| | - Kevin B. Henbest
- Department of Chemistry, Centre for Advanced Electron Spin Resonance, University of Oxford, Oxford, United Kingdom
| | - P. J. Hore
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford, United Kingdom
| | - Stuart R. Mackenzie
- Physical and Theoretical Chemistry Laboratory, Department of Chemistry, University of Oxford, Oxford, United Kingdom
| | - Christiane R. Timmel
- Department of Chemistry, Centre for Advanced Electron Spin Resonance, University of Oxford, Oxford, United Kingdom
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