生物谷：科罗拉多州立大学（Colorado State University）的新研究显示，哺乳动物中所有基因的功能都是受昼夜节律（circadian rhythm；或者说日节律）调控的。此项发表在6月15日PLoS Computational Biology杂志上的文章，驳斥了现有理论，即仅仅10%～15%的基因受到生物钟的影响。尽管在此之前，科学家们已经认识到昼夜节律调控着生物体的行为，但是此项研究将之摆在了更为重要的地位，即日节律可以掌控所有的生命功能，尤其是代谢活动。此项研究认为振荡（oscillation）是生物体所有基因的基本特征，而非之前认为的只是部分基因的特殊功能。
对于在代谢活动中相关基因的振荡特性的了解，有助于我们对基因如何相互作用并调控健康和疾病的理解。科罗拉多州立大学的研究者Andrey Ptitsyn搜集了相关研究，并通过高级计算机算法为98%～99%的基因建立了基线。在之前的研究结果中，当中的大部分基因从未有过与日周期相联系的表达水平变化的报道。甚至于一些基因被认为是持家基因（housekeeping gene），作为基因表达研究的稳定照。
“只要正常进食的人都有体会，人是不能太迟进食的，现在我们离这个现象的答案更近一步了，” 兽医和生物医学学院（College of Veterinary Medicine and Biomedical Sciences）的研究员Ptitsyn介绍说，“我们发现所有的基因在一天过程中总是呈现出显著的变化规律，这种规律体现在了活性的模式，或者表达的模式上。每条基因表达通路都受到昼夜节律的影响，而且不同通路基因的节律的同步性对于生命活动是非常重要的。”
（援引生命经纬）
原始出处:
PLoS Computational Biology Vol. 3, No. 6, e120 doi:10.1371/journal.pcbi.0030120
Digital Signal Processing Reveals Circadian Baseline Oscillation in Majority of Mammalian Genes
Andrey A. Ptitsyn1*, Sanjin Zvonic2, Jeffrey M. Gimble2,3
1 Department of Microbiology, Immunology and Pathology, College of Veterinary and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, United States of America, 2 Stem Cell Laboratory, Clinical Nutrition Research Unit, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana, United States of America, 3 Cell Biology Core Facility, Clinical Nutrition Research Unit, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana, United States of America
In mammals, circadian periodicity has been described for gene expression in the hypothalamus and multiple peripheral tissues. It is accepted that 10%–15% of all genes oscillate in a daily rhythm, regulated by an intrinsic molecular clock. Statistical analyses of periodicity are limited by the small size of datasets and high levels of stochastic noise. Here, we propose a new approach applying digital signal processing algorithms separately to each group of genes oscillating in the same phase. Combined with the statistical tests for periodicity, this method identifies circadian baseline oscillation in almost 100% of all expressed genes. Consequently, circadian oscillation in gene expression should be evaluated in any study related to biological pathways. Changes in gene expression caused by mutations or regulation of environmental factors (such as photic stimuli or feeding) should be considered in the context of changes in the amplitude and phase of genetic oscillations.
Funding. The authors received no specific funding for this study.
Competing interests. The authors have declared that no competing interests exist.
Editor: Roy Kishony, Harvard University, United States of America
Citation: Ptitsyn AA, Zvonic S, Gimble JM (2007) Digital Signal Processing Reveals Circadian Baseline Oscillation in Majority of Mammalian Genes. PLoS Comput Biol 3(6): e120 doi:10.1371/journal.pcbi.0030120
Received: November 14, 2006; Accepted: May 14, 2007; Published: June 15, 2007
Copyright: © 2007 Ptitsyn et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Abbreviations: K-S, Kolmogorov-Smirnov
* To whom correspondence should be addressed. E-mail: Andrey.Ptitsyn@colostate.edu
英文全文链接：
http://compbiol.plosjournals.org/perlserv/?request=get-document&doi=10.1371/journal.pcbi.0030120
