1. Academic Validation
  2. Molecular sensors for temperature detection during behavioral thermoregulation in turtle embryos

Molecular sensors for temperature detection during behavioral thermoregulation in turtle embryos

  • Curr Biol. 2021 Jul 26;31(14):2995-3003.e4. doi: 10.1016/j.cub.2021.04.054.
Yin-Zi Ye 1 Hao Zhang 2 Jiameng Li 3 Ren Lai 4 Shilong Yang 5 Wei-Guo Du 6
Affiliations

Affiliations

  • 1 Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.
  • 2 Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Kunming, Yunnan 650223, China; University of Chinese Academy of Science, Beijing 100049, China.
  • 3 College of Wildlife and Protected Area, Northeast Forestry University, Harbin 150040, China.
  • 4 Key Laboratory of Animal Models and Human Disease Mechanisms of Chinese Academy of Sciences/Key Laboratory of Bioactive Peptides of Yunnan Province, Kunming Institute of Zoology, Kunming, Yunnan 650223, China. Electronic address: rlai@mail.kiz.ac.cn.
  • 5 College of Wildlife and Protected Area, Northeast Forestry University, Harbin 150040, China. Electronic address: syang2020@nefu.edu.cn.
  • 6 Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming 650223, China. Electronic address: duweiguo@ioz.ac.cn.
Abstract

Temperature sensing is essential for the survival of living organisms. Some reptile embryos can reposition themselves within the egg to seek optimal temperatures, but the molecular sensors involved in this temperature detection remain unknown. Here, we show that such thermotaxic behavior is directly determined by the activation of two heat-sensitive ion channels of the turtle: the transient receptor potential ankyrin 1 (MrTRPA1) and transient receptor potential vanilloid-1 (MrTRPV1). These two TRP channels were found to exhibit distinctive distributions among turtle dorsal root ganglion (DRG) neurons. Additionally, our laser irradiation assays illustrated that the heat activation thresholds of MrTRPA1 and MrTRPV1 are consistent with the mild (28-33°C) and noxious (>33°C) heat determined by behavioral tests, respectively. Further pharmacological studies have demonstrated that ligand-induced intervention of MrTRPA1 or MrTRPV1 is sufficient to mimic heat stimuli or block temperature signaling, causing changes in embryo movement. These findings indicate that the initiation of thermotaxic response in turtle embryos relies on a delicate functional balance between the heat activation of MrTRPA1 and MrTRPV1. Our study reveals, for the first time, a unique molecular mechanism underlying thermal detection: the two TRP channels act as a physiological tandem to control the thermotaxic behavior of turtle embryos.

Keywords

TRP; ion channel; temperature detection; thermoregulation; turtle.

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