Rapid cold hardening protects against sublethal freezing injury in an Antarctic insect

Nicholas M. Teets, Yuta Kawarasaki, Leslie J. Potts, Benjamin N. Philip, J. D. Gantz, David L. Denlinger, Richard E. Lee

Research output: Contribution to journalArticlepeer-review

17 Scopus citations


Rapid cold hardening (RCH) is a type of beneficial phenotypic plasticity that occurs on extremely short time scales (minutes to hours) to enhance insects’ ability to cope with cold snaps and diurnal temperature fluctuations. RCH has a well-established role in extending lower lethal limits, but its ability to prevent sublethal cold injury has received less attention. The Antarctic midge, Belgica antarctica, is Antarctica’s only endemic insect and has a well-studied RCH response that extends freeze tolerance in laboratory conditions. However, the discriminating temperatures used in previous studies of RCH are far below those ever experienced in the field. Here, we tested the hypothesis that RCH protects against non-lethal freezing injury. Larvae of B. antarctica were exposed to control (2°C), direct freezing (−9°C for 24 h) or RCH (−5°C for 2 h followed by −9°C for 24 h). All larvae survived both freezing treatments, but RCH larvae recovered more quickly from freezing stress and had a significantly higher metabolic rate during recovery. RCH larvae also sustained less damage to fat body and midgut tissue and had lower expression of two heat shock protein transcripts (hsp60 and hsp90), which is consistent with RCH protecting against protein denaturation. The protection afforded by RCH resulted in energy savings; directly frozen larvae experienced a significant depletion in glycogen energy stores that was not observed in RCH larvae. Together, these results provide strong evidence that RCH protects against a variety of sublethal freezing injuries and allows insects to rapidly fine-tune their performance in thermally variable environments.

Original languageEnglish
Article numberjeb206011
JournalJournal of Experimental Biology
Issue number15
StatePublished - 2019

Bibliographical note

Publisher Copyright:
© 2019. Published by The Company of Biologists Ltd.


  • Acclimation
  • Antarctica
  • Freeze tolerance
  • Heat shock proteins
  • Phenotypic plasticity
  • Stress

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Physiology
  • Aquatic Science
  • Animal Science and Zoology
  • Molecular Biology
  • Insect Science


Dive into the research topics of 'Rapid cold hardening protects against sublethal freezing injury in an Antarctic insect'. Together they form a unique fingerprint.

Cite this