Molecular mechanisms and trade-offs underlying fluctuating thermal regimes during low-temperature storage

• Published in: Current opinion in insect science 2024-04, Vol.62, p.101160, Article 101160
• Main Authors: Torson, Alex S, Yocum, George D, Bowsher, Julia H
• Format: Article
• Language: English
• Subjects: cold storage; insects; mortality; overwintering; reproduction; species
• ISSN: 2214-5745; 2214-5745
• DOI: 10.1016/j.cois.2024.101160

Insects exposed to constant low temperatures (CLT) exhibit high rates of mortality as well as a variety of sublethal effects. In many species, interruptions of CLT with brief pulses of warm temperatures (fluctuating thermal regimes, FTR) lead to increases in survival and fewer sublethal effects. However, we still lack a complete understanding of the physiological mechanisms activated during FTR. In this review, we discuss recent advances in understanding FTR’s underlying molecular mechanisms. We discuss knowledge gaps related to potential trade-offs between FTR’s beneficial effects and the costs of these repairs to overwintering reserves and reproduction. We present the hypothesis that the warm pulse of FTR helps to maintain daily rhythmicity. •Long-term exposure to constant low temperatures (CLT) can lead to chill injury.•Fluctuating thermal regimes (FTR) help to mitigate chill injury.•Recent advances have been made related to ion homeostasis, membrane composition, and oxidative stress.•The costs incurred on the insect by these beneficial mechanisms is still unclear.•We propose additional investigations into the role FTR plays in damage repair and coordinating circadian rhythm.