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Study

Molecular basis of infrared detection by snakes

Gracheva, Elena O.; Ingolia, Nicholas T.; Kelly, Yvonne M.; Cordero-Morales, Julio F.; Julius, David

Nature, 2010

Peer-reviewedcontrolled laboratory experimentlaboratory

Transcriptomes of the trigeminal ganglion — which innervates the heat-sensing pit — were compared against dorsal root ganglia in pit vipers, pythons and boas, looking for a receptor enriched in the heat-sensing pathway. The candidate was then expressed in cells and characterised directly for its temperature response.

Studied in
Crotalus atrox, Python regius, Corallus hortulanus
Sample size
transcriptome comparison plus channel electrophysiology

TRPA1, a channel used elsewhere in vertebrates as an irritant receptor, is massively enriched in the pit-bearing trigeminal ganglion and functions in these snakes as a heat-activated channel. Pit vipers, pythons and boas — three lineages whose pit organs are anatomically distinct and evolved separately — all converged on the same molecule.

What it means

The authors' reading, and ours. Where they differ, that difference is the point.

How the authors put it

Infrared detection in snakes is achieved by co-opting an existing ion channel as a temperature sensor, independently in at least three lineages.

How NatureHQ reads it

The important word is *detection*, and the important correction is that this is not a form of vision. There is no image being formed by photons entering an eye; the pit is a thermal sensor reading warmth radiated onto a membrane, and the brain combines it with sight. It matters for scope too: pits are found in vipers, pythons and boas, which is a minority of snakes. Most snakes have nothing of the kind, and the popular picture of snakes as heat-seeking generally is drawn from a few famous lineages.

  • Molecular identification of the receptor does not by itself establish the spatial resolution of the resulting sense.
  • Behavioural performance was not measured in this study.
  • Three lineages were compared; the pit-bearing snakes are a small fraction of snake diversity.

What this study is used for on NatureHQ

One study can inform several subjects. Here is everywhere this one is cited.

Published by: Nature PortfolioPublished in a Nature Portfolio journal.

doi.org/10.1038/nature08943

This reference was resolved automatically against Crossref on 2026-08-11.

NatureHQ summarises research in its own words and does not reproduce published text. Reviewed 2026-08-11.