temperature regulates transcription in the zebrafish circadian clock温度在斑马鱼生物钟调节转录.pdf

Open access, freely available online PLoS BIOLOGY Temperature Regulates Transcription in the Zebrafish Circadian Clock * Kajori Lahiri, Daniela Vallone, Srinivas Babu Gondi, Cristina Santoriello, Thomas Dickmeis, Nicholas S. Foulkes ¨ ¨ Max-Planck Institut fur Entwicklungsbiologie, Tubingen, Germany It has been well-documented that temperature influences key aspects of the circadian clock. Temperature cycles entrain the clock, while the period length of the circadian cycle is adjusted so that it remains relatively constant over a wide range of temperatures (temperature compensation). In vertebrates, the molecular basis of these properties is poorly understood. Here, using the zebrafish as an ectothermic model, we demonstrate first that in the absence of light, exposure of embryos and primary cell lines to temperature cycles entrains circadian rhythms of clock gene expression. Temperature steps drive changes in the basal expression of certain clock genes in a gene-specific manner, a mechanism potentially contributing to entrainment. In the case of the per4 gene, while E-box promoter elements mediate circadian clock regulation, they do not direct the temperature-driven changes in transcription. Second, by studying E-box-regulated transcription as a reporter of the core clock mechanism, we reveal that the zebrafish clock is temperature-compensated. In addition, temperature strongly influences the amplitude of circadian transcriptional rhythms during and following entrainment by light–dark cycles, a property that could confer temperature compensation.