Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany ; Institute of Functional Interfaces, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
Institute of Toxicology and Genetics, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany.
Biomed Res Int. 2014;2014:930308. doi: 10.1155/2014/930308. Epub 2014 Mar 27.
The circadian clock enables animals to adapt their physiology and behaviour in anticipation of the day-night cycle. Light and temperature represent two key environmental timing cues (zeitgebers) able to reset this mechanism and so maintain its synchronization with the environmental cycle. One key challenge is to unravel how the regulation of the clock by zeitgebers matures during early development. The zebrafish is an ideal model for studying circadian clock ontogeny since the process of development occurs ex utero in an optically transparent chorion and many tools are available for genetic analysis. However, the role played by temperature in regulating the clock during zebrafish development is poorly understood. Here, we have established a clock-regulated luciferase reporter transgenic zebrafish line (Tg (-3.1) per1b::luc) to study the effects of temperature on clock entrainment. We reveal that under complete darkness, from an early developmental stage onwards (48 to 72 hpf), exposure to temperature cycles is a prerequisite for the establishment of self-sustaining rhythms of zfper1b, zfaanat2, and zfirbp expression and also for circadian cell cycle rhythms. Furthermore, we show that following the 5-9 somite stage, the expression of zfper1b is regulated by acute temperature shifts.
生物钟使动物能够预测昼夜周期，从而适应生理和行为。光和温度是两种关键的环境时间线索（zeitgebers），能够重置这个机制，从而保持与环境周期的同步。一个关键的挑战是揭示环境线索如何调节生物钟在早期发育过程中的成熟。斑马鱼是研究生物钟个体发生的理想模型，因为其胚胎外发育过程发生在光学透明的卵黄囊中，并且有许多遗传分析工具可用。然而，温度在调节斑马鱼发育过程中的生物钟方面的作用还知之甚少。在这里，我们建立了一个时钟调节的荧光素酶报告基因转基因斑马鱼系（Tg（-3.1）per1b::luc），以研究温度对时钟驯化的影响。我们揭示了在完全黑暗的条件下，从早期发育阶段（48 到 72 小时）开始，温度循环的暴露是建立 zfper1b、zfaanat2 和 zfirbp 表达的自我维持节律以及昼夜细胞周期节律的前提。此外，我们还表明，在 5-9 体节阶段之后，zfper1b 的表达受到急性温度变化的调节。
