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The Magnetic Compass of Birds: The Role of Cryptochrome

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Journal Front Physiol
Date 2021 Jun 7
PMID 34093230
Citations 19
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Abstract

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

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References
1.
Wiltschko R, Nohr D, Wiltschko W . Pigeons with a deficient sun compass use the magnetic compass. Science. 1981; 214(4518):343-5. DOI: 10.1126/science.7280697. View

2.
Lee A, Lau J, Hogben H, Biskup T, Kattnig D, Hore P . Alternative radical pairs for cryptochrome-based magnetoreception. J R Soc Interface. 2014; 11(95):20131063. PMC: 4006233. DOI: 10.1098/rsif.2013.1063. View

3.
Wiltschko W . [On the effect of static magnetic fields on the migratory orientation of the robin (Erithacus rubecula)]. Z Tierpsychol. 1968; 25(5):537-58. View

4.
Moller A, Sagasser S, Wiltschko W, Schierwater B . Retinal cryptochrome in a migratory passerine bird: a possible transducer for the avian magnetic compass. Naturwissenschaften. 2004; 91(12):585-8. DOI: 10.1007/s00114-004-0578-9. View

5.
Hochstoeger T, Al Said T, Maestre D, Walter F, Vilceanu A, Pedron M . The biophysical, molecular, and anatomical landscape of pigeon CRY4: A candidate light-based quantal magnetosensor. Sci Adv. 2020; 6(33):eabb9110. PMC: 7423367. DOI: 10.1126/sciadv.abb9110. View