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New insights into the limited thermotolerance of anhydrobiotic tardigrades

The recent discovery of an upper limit in the tolerance of an extremotolerant tardigrade to high temperatures is astounding. Although these microinvertebrates are able to endure severe environmental conditions, including desiccation, freezing and high levels of radiation, high temperatures seem to b...

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Autores principales: Neves, Ricardo Cardoso, Stuart, Robyn M., Møbjerg, Nadja
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Taylor & Francis 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7518453/
https://www.ncbi.nlm.nih.gov/pubmed/33014266
http://dx.doi.org/10.1080/19420889.2020.1812865
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author Neves, Ricardo Cardoso
Stuart, Robyn M.
Møbjerg, Nadja
author_facet Neves, Ricardo Cardoso
Stuart, Robyn M.
Møbjerg, Nadja
author_sort Neves, Ricardo Cardoso
collection PubMed
description The recent discovery of an upper limit in the tolerance of an extremotolerant tardigrade to high temperatures is astounding. Although these microinvertebrates are able to endure severe environmental conditions, including desiccation, freezing and high levels of radiation, high temperatures seem to be an Achilles’ heel for active tardigrades. Moreover, exposure-time appears to be a limiting factor for the heat stress tolerance of the otherwise highly resilient desiccated (anhydrobiotic) tardigrades. Indeed, the survival rate of desiccated tardigrades exposed to high temperatures for 24 hours is significantly lower than for exposures of only 1 hour. Here, we investigate the effect of 1 week of high temperature exposures on desiccated tardigrades with the aim of elucidating whether exposure-times longer than 24 hours decrease survival even further. From our analyses we estimate a significant decrease in the 50% mortality temperature from 63ºC to 56ºC for Ramazzottius varieornatus exposed to high temperatures in the desiccated tun state for 24 hours and 1 week, respectively. This negative correlation between exposure-time and tolerance to high temperatures probably results from the interference of intracellular temperature with the homeostasis of macromolecules. We hypothesize that high temperatures denature molecules that play a vital role in sustaining and protecting the anhydrobiotic state.
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spelling pubmed-75184532020-10-01 New insights into the limited thermotolerance of anhydrobiotic tardigrades Neves, Ricardo Cardoso Stuart, Robyn M. Møbjerg, Nadja Commun Integr Biol Short Communication The recent discovery of an upper limit in the tolerance of an extremotolerant tardigrade to high temperatures is astounding. Although these microinvertebrates are able to endure severe environmental conditions, including desiccation, freezing and high levels of radiation, high temperatures seem to be an Achilles’ heel for active tardigrades. Moreover, exposure-time appears to be a limiting factor for the heat stress tolerance of the otherwise highly resilient desiccated (anhydrobiotic) tardigrades. Indeed, the survival rate of desiccated tardigrades exposed to high temperatures for 24 hours is significantly lower than for exposures of only 1 hour. Here, we investigate the effect of 1 week of high temperature exposures on desiccated tardigrades with the aim of elucidating whether exposure-times longer than 24 hours decrease survival even further. From our analyses we estimate a significant decrease in the 50% mortality temperature from 63ºC to 56ºC for Ramazzottius varieornatus exposed to high temperatures in the desiccated tun state for 24 hours and 1 week, respectively. This negative correlation between exposure-time and tolerance to high temperatures probably results from the interference of intracellular temperature with the homeostasis of macromolecules. We hypothesize that high temperatures denature molecules that play a vital role in sustaining and protecting the anhydrobiotic state. Taylor & Francis 2020-09-09 /pmc/articles/PMC7518453/ /pubmed/33014266 http://dx.doi.org/10.1080/19420889.2020.1812865 Text en © 2020 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. https://creativecommons.org/licenses/by/4.0/This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) ), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Short Communication
Neves, Ricardo Cardoso
Stuart, Robyn M.
Møbjerg, Nadja
New insights into the limited thermotolerance of anhydrobiotic tardigrades
title New insights into the limited thermotolerance of anhydrobiotic tardigrades
title_full New insights into the limited thermotolerance of anhydrobiotic tardigrades
title_fullStr New insights into the limited thermotolerance of anhydrobiotic tardigrades
title_full_unstemmed New insights into the limited thermotolerance of anhydrobiotic tardigrades
title_short New insights into the limited thermotolerance of anhydrobiotic tardigrades
title_sort new insights into the limited thermotolerance of anhydrobiotic tardigrades
topic Short Communication
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7518453/
https://www.ncbi.nlm.nih.gov/pubmed/33014266
http://dx.doi.org/10.1080/19420889.2020.1812865
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