Molecular basis of infrared detection by snakes.
Snakes possess a unique sensory system for detecting infrared radiation, enabling them to generate a 'thermal image' of predators or prey. Infrared signals are initially received by the pit organ, a highly specialized facial structure that is innervated by nerve fibres of the somatosensory system. How this organ detects and transduces infrared signals into nerve impulses is not known. Here we use an unbiased transcriptional profiling approach to identify TRPA1 channels as infrared receptors on sensory nerve fibres that innervate the pit organ. TRPA1 orthologues from pit-bearing snakes (vipers, pythons and boas) are the most heat-sensitive vertebrate ion channels thus far identified, consistent with their role as primary transducers of infrared stimuli. Thus, snakes detect infrared signals through a mechanism involving radiant heating of the pit organ, rather than photochemical transduction. These findings illustrate the broad evolutionary tuning of transient receptor potential (TRP) channels as thermosensors in the vertebrate nervous system.
Department of Physiology, University of California, San Francisco, California 94158-2517, USA.
Elena O
EO
Gracheva
Nicholas T
NT
Ingolia
Yvonne M
YM
Kelly
Julio F
JF
Cordero-Morales
Gunther
G
Hollopeter
Alexander T
AT
Chesler
Elda E
EE
Sánchez
John C
JC
Perez
Jonathan S
JS
Weissman
David
D
Julius
D000818:Animals; D017821:Boidae / Q000235:genetics / Q000378:metabolism; D002645:Chickens; D003001:Cloning, Molecular; D017839:Crotalus / Q000033:anatomy & histology / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D006358:Hot Temperature; D007259:Infrared Rays; D055537:Light Signal Transduction / Q000502:physiology* / Q000528:radiation effects*; D008969:Molecular Sequence Data; D011235:Predatory Behavior / Q000502:physiology / Q000528:radiation effects; D051381:Rats; D011984:Sensory Receptor Cells / Q000378:metabolism; D050051:Transient Receptor Potential Channels / Q000235:genetics / Q000378:metabolism*; D012668:Trigeminal Ganglion / Q000166:cytology / Q000378:metabolism
D050051:Transient Receptor Potential Channels