据新华社巴黎11月15日电，法国国家科研中心15日发表公报说，该机构研究人员通过对绿藻的观测，揭开了生物钟“守时”的秘密。
为了揭开其中的奥秘，法国国家科研中心巴纽尔斯海洋观测站的研究人员对常见的单细胞绿藻进行了24小时观测，并根据其体内蛋白质的生成数量绘制了曲线图。结果他们发现，生物钟只在某些特定时刻对光线敏感，比如早上日出或晚间日落的时刻，在其他时间里，生物钟能够“守时”是由于基因和蛋白质的调节机制发挥作用。
在这种机制作用下，生物体内蛋白质数量会定时增长或是消退。比如基因A能够生成蛋白质，激发基因B的活性，后者在被激活后同样产生蛋白质，让基因A停止活动，如此周而复始，在24小时内，生物体内的蛋白质数量随着时间不断变化，会从零开始达到一定数量，然后又自动消退，从而使生物钟发挥作用。
这项成果发表在新一期的美国《科学公共图书馆计算生物学》杂志上。目前，研究人员正在进行深入研究，希望验证这种机制是否适用于人类。（生物谷Bioon.com）
更多阅读
Cell：生物钟调节基因可影响机体代谢
PNAS：生物钟与血糖调节密切相关
PNAS：头发助检测人体的生物钟
Nature：影响生物钟节律PRMT5蛋白质
生物谷推荐英文摘要：
PLoS Comput Biol 6(11): e1000990. doi:10.1371/journal.pcbi.1000990
Robustness of Circadian Clocks to Daylight Fluctuations: Hints from the Picoeucaryote Ostreococcus tauri
Quentin Thommen1,2,3,4, Benjamin Pfeuty1,2,3,4, Pierre-Emmanuel Morant1,2,3,4, Florence Corellou5,6, Fran?ois-Yves Bouget5,6, Marc Lefranc1,2,3,4*
1 Laboratoire de Physique des Lasers, Atomes, et Molécules, UFR de Physique, Université Lille 1, Villeneuve d'Ascq, France, 2 Centre National de la Recherche Scientifique, UMR 8523, Villeneuve d'Ascq Cedex, France, 3 Institut de Recherche Interdisciplinaire, Université Lille 1, Villeneuve d'Ascq, France, 4 Centre National de la Recherche Scientifique, USR 3078, Villeneuve d'Ascq, France, 5 Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, Université Pierre and Marie Curie Paris 06, Banyuls/Mer, France, 6 Laboratoire d'Océanographie Microbienne, Observatoire Océanologique, Centre National de la Recherche Scientifique, Banyuls/Mer, France
The development of systemic approaches in biology has put emphasis on identifying genetic modules whose behavior can be modeled accurately so as to gain insight into their structure and function. However, most gene circuits in a cell are under control of external signals and thus, quantitative agreement between experimental data and a mathematical model is difficult. Circadian biology has been one notable exception: quantitative models of the internal clock that orchestrates biological processes over the 24-hour diurnal cycle have been constructed for a few organisms, from cyanobacteria to plants and mammals. In most cases, a complex architecture with interlocked feedback loops has been evidenced. Here we present the first modeling results for the circadian clock of the green unicellular alga Ostreococcus tauri. Two plant-like clock genes have been shown to play a central role in the Ostreococcus clock. We find that their expression time profiles can be accurately reproduced by a minimal model of a two-gene transcriptional feedback loop. Remarkably, best adjustment of data recorded under light/dark alternation is obtained when assuming that the oscillator is not coupled to the diurnal cycle. This suggests that coupling to light is confined to specific time intervals and has no dynamical effect when the oscillator is entrained by the diurnal cycle. This intringuing property may reflect a strategy to minimize the impact of fluctuations in daylight intensity on the core circadian oscillator, a type of perturbation that has been rarely considered when assessing the robustness of circadian clocks.
