Sensing Magnetic Directions in Birds: Radical Pair Processes Involving Cryptochrome

Birds can use the geomagnetic field for compass orientation. Behavioral experiments, mostly with migrating passerines, revealed three characteristics of the avian magnetic compass: (1) it works spontaneously only in a narrow functional window around the intensity of the ambient magnetic field, but c...

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Main Authors: Roswitha Wiltschko, Wolfgang Wiltschko
Format: Article
Language:English
Published: MDPI AG 2014-07-01
Series:Biosensors
Subjects:
Online Access:http://www.mdpi.com/2079-6374/4/3/221
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author Roswitha Wiltschko
Wolfgang Wiltschko
author_facet Roswitha Wiltschko
Wolfgang Wiltschko
author_sort Roswitha Wiltschko
collection DOAJ
description Birds can use the geomagnetic field for compass orientation. Behavioral experiments, mostly with migrating passerines, revealed three characteristics of the avian magnetic compass: (1) it works spontaneously only in a narrow functional window around the intensity of the ambient magnetic field, but can adapt to other intensities, (2) it is an “inclination compass”, not based on the polarity of the magnetic field, but the axial course of the field lines, and (3) it requires short-wavelength light from UV to 565 nm Green. The Radical Pair-Model of magnetoreception can explain these properties by proposing spin-chemical processes in photopigments as underlying mechanism. Applying radio frequency fields, a diagnostic tool for radical pair processes, supports an involvement of a radical pair mechanism in avian magnetoreception: added to the geomagnetic field, they disrupted orientation, presumably by interfering with the receptive processes. Cryptochromes have been suggested as receptor molecules. Cry1a is found in the eyes of birds, where it is located at the membranes of the disks in the outer segments of the UV-cones in chickens and robins. Immuno-histochemical studies show that it is activated by the wavelengths of light that allow magnetic compass orientation in birds.
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spelling doaj.art-3c980c516f1b41ee9342a0556ae8a5be2022-12-22T01:51:20ZengMDPI AGBiosensors2079-63742014-07-014322124210.3390/bios4030221bios4030221Sensing Magnetic Directions in Birds: Radical Pair Processes Involving CryptochromeRoswitha Wiltschko0Wolfgang Wiltschko1Fachbereich Biowissenschaften, J.W. Goethe-Universität Frankfurt, Max von Laue Straße 13, D-60438 Frankfurt am Main, GermanyFachbereich Biowissenschaften, J.W. Goethe-Universität Frankfurt, Max von Laue Straße 13, D-60438 Frankfurt am Main, GermanyBirds can use the geomagnetic field for compass orientation. Behavioral experiments, mostly with migrating passerines, revealed three characteristics of the avian magnetic compass: (1) it works spontaneously only in a narrow functional window around the intensity of the ambient magnetic field, but can adapt to other intensities, (2) it is an “inclination compass”, not based on the polarity of the magnetic field, but the axial course of the field lines, and (3) it requires short-wavelength light from UV to 565 nm Green. The Radical Pair-Model of magnetoreception can explain these properties by proposing spin-chemical processes in photopigments as underlying mechanism. Applying radio frequency fields, a diagnostic tool for radical pair processes, supports an involvement of a radical pair mechanism in avian magnetoreception: added to the geomagnetic field, they disrupted orientation, presumably by interfering with the receptive processes. Cryptochromes have been suggested as receptor molecules. Cry1a is found in the eyes of birds, where it is located at the membranes of the disks in the outer segments of the UV-cones in chickens and robins. Immuno-histochemical studies show that it is activated by the wavelengths of light that allow magnetic compass orientation in birds.http://www.mdpi.com/2079-6374/4/3/221avian magnetic compassinclination compassfunctional windowRadical Pair ModelcryptochromeCry 1aretinaUV/V cones
spellingShingle Roswitha Wiltschko
Wolfgang Wiltschko
Sensing Magnetic Directions in Birds: Radical Pair Processes Involving Cryptochrome
Biosensors
avian magnetic compass
inclination compass
functional window
Radical Pair Model
cryptochrome
Cry 1a
retina
UV/V cones
title Sensing Magnetic Directions in Birds: Radical Pair Processes Involving Cryptochrome
title_full Sensing Magnetic Directions in Birds: Radical Pair Processes Involving Cryptochrome
title_fullStr Sensing Magnetic Directions in Birds: Radical Pair Processes Involving Cryptochrome
title_full_unstemmed Sensing Magnetic Directions in Birds: Radical Pair Processes Involving Cryptochrome
title_short Sensing Magnetic Directions in Birds: Radical Pair Processes Involving Cryptochrome
title_sort sensing magnetic directions in birds radical pair processes involving cryptochrome
topic avian magnetic compass
inclination compass
functional window
Radical Pair Model
cryptochrome
Cry 1a
retina
UV/V cones
url http://www.mdpi.com/2079-6374/4/3/221
work_keys_str_mv AT roswithawiltschko sensingmagneticdirectionsinbirdsradicalpairprocessesinvolvingcryptochrome
AT wolfgangwiltschko sensingmagneticdirectionsinbirdsradicalpairprocessesinvolvingcryptochrome