Revel Florent G, Herwig Annika, Garidou Marie-Laure, Dardente Hugues, Menet Jérôme S, Masson-Pévet Mireille, Simonneaux Valérie, Saboureau Michel, Pévet Paul
Département de Neurobiologie des Rythmes, Institut des Neurosciences Cellulaires et Intégratives, Unité Mixte de Recherche 7168/LC2, Centre National de la Recherche Scientifique, Université Louis Pasteur, Strasbourg Cedex, France.
Proc Natl Acad Sci U S A. 2007 Aug 21;104(34):13816-20. doi: 10.1073/pnas.0704699104.
Hibernation is a fascinating, yet enigmatic, physiological phenomenon during which body temperature and metabolism are reduced to save energy. During the harsh season, this strategy allows substantial energy saving by reducing body temperature and metabolism. Accordingly, biological processes are considerably slowed down and reduced to a minimum. However, the persistence of a temperature-compensated, functional biological clock in hibernating mammals has long been debated. Here, we show that the master circadian clock no longer displays 24-h molecular oscillations in hibernating European hamsters. The clock genes Per1, Per2, and Bmal1 and the clock-controlled gene arginine vasopressin were constantly expressed in the suprachiasmatic nucleus during deep torpor, as assessed by radioactive in situ hybridization. Finally, the melatonin rhythm-generating enzyme, arylalkylamine N-acetyltransferase, whose rhythmic expression in the pineal gland is controlled by the master circadian clock, no longer exhibits day/night changes of expression but constantly elevated mRNA levels over 24 h. Overall, these data provide strong evidence that in the European hamster the molecular circadian clock is arrested during hibernation and stops delivering rhythmic output signals.
冬眠是一种迷人但又神秘的生理现象，在此期间体温和新陈代谢会降低以节省能量。在严酷季节，这种策略通过降低体温和新陈代谢实现大量能量节省。相应地，生物过程会大幅减缓并降至最低限度。然而，冬眠哺乳动物中温度补偿性的功能性生物钟的持续性长期以来一直存在争议。在此，我们表明，在冬眠的欧洲仓鼠中，主生物钟不再呈现24小时的分子振荡。通过放射性原位杂交评估发现，在深度蛰伏期间，生物钟基因Per1、Per2和Bmal1以及生物钟控制基因精氨酸加压素在视交叉上核中持续表达。最后，褪黑素节律生成酶——芳基烷基胺N - 乙酰基转移酶，其在松果体中的节律性表达受主生物钟控制，不再呈现昼夜表达变化，而是在24小时内mRNA水平持续升高。总体而言，这些数据提供了有力证据，表明在欧洲仓鼠中，分子生物钟在冬眠期间停止运行并停止传递节律性输出信号。
