High-temperature tolerance in anhydrobiotic tardigrades is limited by glass transition
Hengherr, S.; Worland, Michael Roger; Reuner, A.; Brümmer, F.; Schill, R.O.. 2009 High-temperature tolerance in anhydrobiotic tardigrades is limited by glass transition. Physiological and Biochemical Zoology, 82 (6). 749-755. 10.1086/605954Full text not available from this repository. (Request a copy)
Survival in microhabitats that experience extreme fluctuations in water availability and temperature requires special adaptations. To withstand such environmental conditions, tardigrades, as well as some nematodes and rotifers, enter a completely desiccated state known as anhydrobiosis. We examined the effects of high temperatures on fully desiccated (anhydrobiotic) tardigrades. Nine species from the classes Heterotardigrada and Eutardigrada were exposed to temperatures of up to 110 degrees C for 1 h. Exposure to temperatures of up to 80 degrees C resulted in a moderate decrease in survival. Exposure to temperatures above this resulted in a sharp decrease in survival, with no animals of the families Macrobiotidae and Echiniscidae surviving 100 degrees C. However, Milnesium tardigradum (Milnesidae) showed survival of >90% after exposure to 100 degrees C; temperatures above this resulted in a steep decrease in survival. Vitrification is assumed to play a major role in the survival of anhydrobiotic organisms during exposure to extreme temperatures, and consequently, the glass-transition temperature (T-g) is critical to high-temperature tolerance. In this study, we provide the first evidence of the presence of a glass transition during heating in an anhydrobiotic tardigrade through the use of differential scanning calorimetry.
|Programmes:||BAS Programmes > Polar Science for Planet Earth (2009 - ) > Ecosystems|
|NORA Subject Terms:||Biology and Microbiology
Ecology and Environment
|Date made live:||02 Nov 2010 13:20|
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