Thermal limit for metazoan life in question: in vivo heat tolerance of the Pompeii worm.

TitleThermal limit for metazoan life in question: in vivo heat tolerance of the Pompeii worm.
Publication TypeJournal Article
Year of Publication2013
AuthorsRavaux, J, Hamel, G, Zbinden, M, Tasiemski, AA, Boutet, I, Léger, N, Tanguy, A, Jollivet, D, Shillito, B
JournalPLoS One
Date Published2013
KeywordsAdaptation, Physiological, Animals, Environment, Controlled, Gene Expression Profiling, Heat-Shock Response, Hot Temperature, HSP70 Heat-Shock Proteins, Molecular Sequence Data, Polychaeta, Pressure, Reverse Transcriptase Polymerase Chain Reaction, Temperature

The thermal limit for metazoan life, expected to be around 50°C, has been debated since the discovery of the Pompeii worm Alvinella pompejana, which colonizes black smoker chimney walls at deep-sea vents. While indirect evidence predicts body temperatures lower than 50°C, repeated in situ temperature measurements depict an animal thriving at temperatures of 60°C and more. This controversy was to remain as long as this species escaped in vivo investigations, due to irremediable mortalities upon non-isobaric sampling. Here we report from the first heat-exposure experiments with live A. pompejana, following isobaric sampling and subsequent transfer in a laboratory pressurized aquarium. A prolonged (2 hours) exposure in the 50-55°C range was lethal, inducing severe tissue damages, cell mortalities and triggering a heat stress response, therefore showing that Alvinella's upper thermal limit clearly is below 55°C. A comparison with hsp70 stress gene expressions of individuals analysed directly after sampling in situ confirms that Alvinella pompejana does not experience long-term exposures to temperature above 50°C in its natural environment. The thermal optimum is nevertheless beyond 42°C, which confirms that the Pompeii worm ranks among the most thermotolerant metazoans.

Alternate JournalPLoS ONE
PubMed ID23734185
PubMed Central IDPMC3667023