Three families of snakes use infrared waves
to detect prey and differences in environmental temperatures. The mechanism involved
in this has only been recently discovered to involve the transient receptor
potential (TRP) ion channels. TRPs are involved in various biological
processes, including calcium and magnesium homeostasis, neuronal growth,
temperature sensation, and pain sensation. The sensations caused by the pungent
agents of wasabi and other mustard plants are generated by our transient
receptor potential ankyrin 1 (TRPA1) channel. Recently, it has been discovered
that the orthologous receptors (receptors sharing a common ancestral gene) of
the western diamondback rattlesnake (Crotalus atrox), ball python (Python
regius), and garden tree boa (Corallus hortulanus) detect
infrared radiation, while those the Texas rat snake (Pantherophis obsoletus
lindheimeri) does not. The genetic mechanism of infrared sensitivity of
these snake-specific TRPA1 proteins is unknown. Yokoyama et al. (2011) have now
identified the amino acid changes that are responsible for the dramatic
functional changes in the three groups of snakes. They suggest three parallel
amino acid changes (L330M, Q391H, and S434T) are responsible for the
development of infrared vision in the three groups of snakes. Protein modeling
shows that the three amino acid changes alter the structures of the central
region of their ankyrin repeats. The article can be found on-line.
Citation:
Yokoyama, S., A. Altun, and D. F. DeNardo.
2011. Molecular convergence of infrared vision in snakes. Molecular Biology and Evolution 28(1):
45-48. doi:10.1093/molbev/msq267Labels: evolution, infrared receptors, snakes
