School of Biological and Chemical Sciences, Queen Mary, University of London, London E1 4NS, UK.
Proc Biol Sci. 2013 Oct 7;280(1768):20130959. doi: 10.1098/rspb.2013.0959.
Circadian clocks are endogenous approximately 24 h oscillators that temporally regulate many physiological and behavioural processes. In order to be beneficial for the organism, these clocks must be synchronized with the environmental cycles on a daily basis. Both light : dark and the concomitant daily temperature cycles (TCs) function as Zeitgeber ('time giver') and efficiently entrain circadian clocks. The temperature receptors mediating this synchronization have not been identified. Transient receptor potential (TRP) channels function as thermo-receptors in animals, and here we show that the Pyrexia (Pyx) TRP channel mediates temperature synchronization in Drosophila melanogaster. Pyx is expressed in peripheral sensory organs (chordotonal organs), which previously have been implicated in temperature synchronization. Flies deficient for Pyx function fail to synchronize their behaviour to TCs in the lower range (16-20°C), and this deficit can be partially rescued by introducing a wild-type copy of the pyx gene. Synchronization to higher TCs is not affected, demonstrating a specific role for Pyx at lower temperatures. In addition, pyx mutants speed up their clock after being exposed to TCs. Our results identify the first TRP channel involved in temperature synchronization of circadian clocks.
生物钟是内源性的大约 24 小时振荡器，它在时间上调节许多生理和行为过程。为了对生物体有益，这些生物钟必须每天与环境周期同步。光：暗和伴随的每日温度周期（TCs）作为 Zeitgeber（“时间给予者”）有效地使生物钟同步。介导这种同步的温度感受器尚未确定。瞬时受体电位（TRP）通道在动物中作为热感受器发挥作用，在这里我们表明，发热（Pyx）TRP 通道介导果蝇中的温度同步。Pyx 在周围感觉器官（弦音器官）中表达，先前已被牵连到温度同步中。缺乏 Pyx 功能的果蝇无法将其行为与较低范围（16-20°C）的 TCs 同步，并且可以通过引入野生型 pyx 基因的副本部分挽救这种缺陷。对较高 TCs 的同步不受影响，表明 Pyx 在较低温度下具有特定作用。此外，暴露于 TCs 后，pyx 突变体会加速其生物钟。我们的结果确定了第一个参与生物钟温度同步的 TRP 通道。
