TY - JOUR

T1 - Biochemical response to freezing in the Siberian salamander Salamandrella keyserlingii

AU - Shekhovtsov, Sergei V.

AU - Bulakhova, Nina A.

AU - Tsentalovich, Yuri P.

AU - Zelentsova, Ekaterina A.

AU - Meshcheryakova, Ekaterina N.

AU - Poluboyarova, Tatiana V.

AU - Berman, Daniil I.

N1 - Funding Information: Funding: This study was supported by the Russian Science Foundation (RSF) grant no. 21-74-20050. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

PY - 2021/11

Y1 - 2021/11

N2 - The Siberian salamander Salamandrella keyserlingii Dybowski, 1870 is a unique amphibian that is capable to survive long-term freezing at −55◦ C. Nothing is known on the biochemical basis of this remarkable freezing tolerance, except for the fact that it uses glycerol as a low molecular weight cryoprotectant. We used1 H-NMR analysis to study quantitative changes of multiple metabolites in liver and hindlimb muscle of S. keyserlingii in response to freezing. For the majority of molecules we observed significant changes in concentrations. Glycerol content in frozen organs was as high as 2% w/w, which confirms its role as a cryoprotectant. No other putative cryoprotectants were detected. Freezing resulted in ischemia manifested as increased concentrations of glycolysis products: lactate and alanine. Unexpectedly, we detected no increase in concentrations of succinate, which accumulates under ischemia in various tetrapods. Freezing proved to be a dramatic stress with reduced adenosine phosphate pool and high levels of nucleotide degradation products (hypoxanthine, β-alanine, and β-aminoisobutyrate). There was also significant increase in the concentrations of choline and glycerophosphocholine, which may be interpreted as the degradation of biomembranes. Thus, we found that freezing results not only in macroscopical damage due to ice formation, but also to degradation of DNA and biomembranes.

AB - The Siberian salamander Salamandrella keyserlingii Dybowski, 1870 is a unique amphibian that is capable to survive long-term freezing at −55◦ C. Nothing is known on the biochemical basis of this remarkable freezing tolerance, except for the fact that it uses glycerol as a low molecular weight cryoprotectant. We used1 H-NMR analysis to study quantitative changes of multiple metabolites in liver and hindlimb muscle of S. keyserlingii in response to freezing. For the majority of molecules we observed significant changes in concentrations. Glycerol content in frozen organs was as high as 2% w/w, which confirms its role as a cryoprotectant. No other putative cryoprotectants were detected. Freezing resulted in ischemia manifested as increased concentrations of glycolysis products: lactate and alanine. Unexpectedly, we detected no increase in concentrations of succinate, which accumulates under ischemia in various tetrapods. Freezing proved to be a dramatic stress with reduced adenosine phosphate pool and high levels of nucleotide degradation products (hypoxanthine, β-alanine, and β-aminoisobutyrate). There was also significant increase in the concentrations of choline and glycerophosphocholine, which may be interpreted as the degradation of biomembranes. Thus, we found that freezing results not only in macroscopical damage due to ice formation, but also to degradation of DNA and biomembranes.

KW - Cryoprotectants

KW - Freeze tolerance

KW - Freezing

KW - Glycolysis

KW - Salamandrella keyserlingii

KW - Siberian salamander

UR - http://www.scopus.com/inward/record.url?scp=85119675271&partnerID=8YFLogxK

UR - https://www.elibrary.ru/item.asp?id=47527944

U2 - 10.3390/biology10111172

DO - 10.3390/biology10111172

M3 - Article

C2 - 34827165

AN - SCOPUS:85119675271

VL - 10

JO - Biology

JF - Biology

SN - 2079-7737

IS - 11

M1 - 1172

ER -