Title
Cryptochrome mediates light-dependent magnetosensitivity in Drosophila
PubMed ID
18641630
UMMS Affiliation
Department of Neurobiology
Date
7-22-2008
Document Type
Article
Subjects
Animals; Behavior, Animal; Circadian Rhythm; Drosophila melanogaster; Flavoproteins; *Light; *Magnetics; Mutation; Sensation
Disciplines
Life Sciences | Medicine and Health Sciences
Abstract
Although many animals use the Earth's magnetic field for orientation and navigation, the precise biophysical mechanisms underlying magnetic sensing have been elusive. One theoretical model proposes that geomagnetic fields are perceived by chemical reactions involving specialized photoreceptors. However, the specific photoreceptor involved in such magnetoreception has not been demonstrated conclusively in any animal. Here we show that the ultraviolet-A/blue-light photoreceptor cryptochrome (Cry) is necessary for light-dependent magnetosensitive responses in Drosophila melanogaster. In a binary-choice behavioural assay for magnetosensitivity, wild-type flies show significant naive and trained responses to a magnetic field under full-spectrum light ( approximately 300-700 nm) but do not respond to the field when wavelengths in the Cry-sensitive, ultraviolet-A/blue-light part of the spectrum (<420 nm) are blocked. Notably, Cry-deficient cry(0) and cry(b) flies do not show either naive or trained responses to a magnetic field under full-spectrum light. Moreover, Cry-dependent magnetosensitivity does not require a functioning circadian clock. Our work provides, to our knowledge, the first genetic evidence for a Cry-based magnetosensitive system in any animal.
Rights and Permissions
Citation: Nature. 2008 Aug 21;454(7207):1014-8. Epub 2008 Jul 20. Link to article on publisher's site