Cryobiologists have traditionally assumed that the temperature of crystallisation (Tc) or supercooling point (SCP) of a chill-tolerant insect is not a stochastic event, i.e. that it is a biologically meaningful indicator of phenotypic characteristics, be they exogenous influences (e.g. acclimation/acclimatization) or endogenous factors (e.g. life history stage, moult state). Recent work by Wilson et al. (11) has suggested that SCPs – at least in non-biological samples – are more stochastic than previously thought. Here, this question is tested indirectly by the repetitive freezing of individuals of the Antarctic springtail, Cryptopygus antarcticus. The springtails were each supercooled ten times in succession to determine their recrystallisation temperatures (Trc). SCPs were found to be deterministic i.e. related to their initial Tc. Despite the mortality of re-crystallised samples, 70% showed <1°C difference between Tc and Trc1 and 95% showed <5°C difference. Tc and Trc1 were significantly correlated. Variability in re-crystallisation temperatures is hypothesised to be predominantly the result of differences in nucleator content and changes in body fluid osmolality during the experimental exposures. Factors affecting the relative variability of SCPs are discussed.
No Supplementary Data.
No Article Media
Document Type: Research Article
Publication date: November 1, 2006
More about this publication?
CryoLetters is a bimonthly international journal for low temperature sciences, including cryobiology, cryopreservation or vitrification of cells and tissues, chemical and physical aspects of freezing and drying, and studies involving ecology of cold environments, and cold adaptation
The journal publishes original research reports, authoritative reviews, technical developments and commissioned book reviews of studies of the effects produced by low temperatures on a wide variety of scientific and technical processes, or those involving low temperature techniques in the investigation of physical, chemical, biological and ecological problems.