Light-dependent magnetic compass orientation in amphibians and insects: candidate receptors and candidate molecular mechanisms.
Magnetic compass orientation by amphibians, and some insects, is mediated by a light-dependent magnetoreception mechanism. Cryptochrome photopigments, best known for their role in circadian rhythms, are proposed to mediate such responses. In this paper, we explore light-dependent properties of magnetic sensing at three levels: (i) behavioural (wavelength-dependent effects of light on magnetic compass orientation), (ii) physiological (photoreceptors/photopigment systems with properties suggesting a role in magnetoreception), and (iii) molecular (cryptochrome-based and non-cryptochrome-based signalling pathways that are compatible with behavioural responses). Our goal is to identify photoreceptors and signalling pathways that are likely to play a specialized role in magnetoreception in order to definitively answer the question of whether the effects of light on magnetic compass orientation are mediated by a light-dependent magnetoreception mechanism, or instead are due to input from a non-light-dependent (e.g. magnetite-based) magnetoreception mechanism that secondarily interacts with other light-dependent processes.
Phillips
John B
JB
Department of Biological Sciences, Virginia Polytechnic Institute and State University, Derring Hall, Blacksburg, VA 24061, USA. jphillip@vt.edu
Jorge
Paulo E
PE
Muheim
Rachel
R
D000663:Amphibians / Q000502:physiology*; D000818:Animals; D056931:Cryptochromes / Q000378:metabolism*; D004574:Electromagnetic Fields; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D007313:Insecta / Q000502:physiology*; D008027:Light; D009949:Orientation / Q000502:physiology* / Q000528:radiation effects*; D010465:Perception / Q000502:physiology / Q000528:radiation effects
D056931:Cryptochromes