Temperature signaling underlying thermotaxis and cold tolerance in Caenorhabditis elegans

Abstract

Caenorhabditis elegans has a simple nervous system of 302 neurons. It however senses environmental cues incredibly precisely and produces various behaviors by processing information in the neural circuit. In addition to classical genetic analysis, fluorescent proteins and calcium indicators enable in vivo monitoring of protein dynamics and neural activity on either fixed or free-moving worms. These analyses have provided the detailed molecular mechanisms of neuronal and systemic signaling that regulate worm responses. Here, we focus on responses of C. elegans against temperature and review key findings that regulate thermotaxis and cold tolerance. Thermotaxis of C. elegans has been studied extensively for almost 50 years, and cold tolerance is a relatively recent concept in C. elegans. Although both thermotaxis and cold tolerance require temperature sensation, the responsible neurons and molecular pathways are different, and C. elegans uses the proper mechanisms depending on its situation. We summarize the molecular mechanisms of the major thermosensory circuit as well as the modulatory strategy through neural and tissue communication that enables fine tuning of thermotaxis and cold tolerance.

Keywords:

• Caenorhabditis elegans
• thermotaxis
• cold tolerance
• temperature sensation

Acknowledgements

We thank P. Sengupta for comments on this manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

A.K. was supported by the Asahi Glass Foundation, the Takeda Science Foundation, the Suzuken Memorial Foundation, the Hirao Taro Foundation of KONAN GAKUEN for Academic Research, AMED Mechano Biology [19gm5810024h0003, 20gm5810024h0004], KAKENHI from JSPS and MEXT Japan [17K19410, 18H02484, 15H05928].