TY - JOUR

T1 - Extreme freeze-tolerance in cryophilic tardigrades relies on controlled ice formation but does not involve significant change in transcription

T2 - [Corrigendum]

AU - Møbjerg, Ask

AU - Kodama, Miyako

AU - Ramos-Madrigal, Jazmín

AU - Neves, Ricardo Cardoso

AU - Jørgensen, Aslak

AU - Schiøtt, Morten

AU - Gilbert, M. Thomas P.

AU - Møbjerg, Nadja

N1 - Corrigendum to “Extreme freeze-tolerance in cryophilic tardigrades relies on controlled ice formation but does not involve significant change in transcription” [Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology 271 (2022), 111245] 10.1016/j.cbpa.2022.111317 https://www.sciencedirect.com/science/article/pii/S1095643322001751?via%3Dihub Copyright © 2022. Published by Elsevier Inc.

PY - 2022

Y1 - 2022

N2 - Subzero temperatures are among the most significant factors defining the distribution of organisms, yet, certain taxa have evolved to overcome this barrier. The microscopic tardigrades are among the most freeze-tolerant animals, with selected species reported to survive milli-Kelvin temperatures. Here, we estimate survival of fully hydrated eutardigrades of the species Ramazzottius varieornatus following exposures to -20 °C and - 80 °C as well as -196 °C with or without initial cooling to -80 °C. The tardigrades easily survive these temperatures, yet with a significant decrease in viability following rapid cooling by direct exposure to -196 °C. Hence, post-freeze recovery of R. varieornatus seems to rely on cooling rate and thus controlled ice formation. Cryophilic organisms are renowned for having cold-active enzymes that secure appropriate reaction rates at low temperatures. Hence, extreme freeze-tolerance in R. varieornatus could potentially involve syntheses of cryoprotectants and de novo transcription. We therefore generated a reference transcriptome for this cryophilic R. varieornatus population and explored for differential gene expression patterns following cooling to -80 °C as compared to active 5 °C controls. Specifically, we tested for fast transcription potentially occurring within 25 min of cooling from room temperature to a supercooling point of ca. -20 °C, at which the tardigrades presumably freeze and enter into the ametabolic state of cryobiosis. Our analyses revealed no evidence for differential gene expression. We, therefore, conclude that extreme freeze-tolerance in R. varieornatus relies on controlled extracellular freezing with any freeze-tolerance related genes being constitutively expressed.

AB - Subzero temperatures are among the most significant factors defining the distribution of organisms, yet, certain taxa have evolved to overcome this barrier. The microscopic tardigrades are among the most freeze-tolerant animals, with selected species reported to survive milli-Kelvin temperatures. Here, we estimate survival of fully hydrated eutardigrades of the species Ramazzottius varieornatus following exposures to -20 °C and - 80 °C as well as -196 °C with or without initial cooling to -80 °C. The tardigrades easily survive these temperatures, yet with a significant decrease in viability following rapid cooling by direct exposure to -196 °C. Hence, post-freeze recovery of R. varieornatus seems to rely on cooling rate and thus controlled ice formation. Cryophilic organisms are renowned for having cold-active enzymes that secure appropriate reaction rates at low temperatures. Hence, extreme freeze-tolerance in R. varieornatus could potentially involve syntheses of cryoprotectants and de novo transcription. We therefore generated a reference transcriptome for this cryophilic R. varieornatus population and explored for differential gene expression patterns following cooling to -80 °C as compared to active 5 °C controls. Specifically, we tested for fast transcription potentially occurring within 25 min of cooling from room temperature to a supercooling point of ca. -20 °C, at which the tardigrades presumably freeze and enter into the ametabolic state of cryobiosis. Our analyses revealed no evidence for differential gene expression. We, therefore, conclude that extreme freeze-tolerance in R. varieornatus relies on controlled extracellular freezing with any freeze-tolerance related genes being constitutively expressed.

U2 - 10.1016/j.cbpa.2022.111245

DO - 10.1016/j.cbpa.2022.111245

M3 - Journal article

C2 - 35640792

VL - 271

JO - Comparative biochemistry and physiology. Part A, Molecular & integrative physiology

JF - Comparative biochemistry and physiology. Part A, Molecular & integrative physiology

SN - 1095-6433

M1 - 111245

ER -