弗吉尼亚的生物技术专家和工程学专家建立了一套数学模型，根据这一模型，研究者可以观察细胞在分裂周期中处理信息的模式，其中有多少分子会参与其中。这一有趣的成果发表在最新一期的《美国科学院院报》（PNAS）上。
参与研究的有博士后Sandip Kar，电子计算机工程学教授William Baumann，工程机制研究教授，著名的生物科学教授John Tyson。
研究小组以单个酵母细胞为模型，研究细胞的信息流，输入的信息流和输出的信息流，细胞中mRNA的流向和功效。
研究结果表明，在细胞分裂周期中平均参与的mRNA数是正常状态下的5-10倍；mRNA分子的半衰期比正常状态下短10-20倍；在细胞中，有50%的蛋白传递的信息是杂音，因此细胞必然有套独特的消除背景本底的系统以便清除一些无用的信息。研究发现在细胞中每个基因对应一个mRNA分子，每个mRNA分子只有15-20分钟的存活时间，之后便降解。（生物谷Bioon.com）
生物谷推荐原始出处：
PNAS February 25, 2009, doi: 10.1073/pnas.0810034106
Exploring the roles of noise in the eukaryotic cell cycle
Sandip Kara, William T. Baumannb, Mark R. Paulc and John J. Tysona,1
aDepartments of aBiological Sciences,
bElectrical and Computer Engineering, and
cMechanical EngineeringVirginia Polytechnic Institute and State UniversityBlacksburg, VA 24061
Edited by John RossStanford UniversityStanfordCA approved January 11, 2009 (received for review December 30, 2008)
Abstract
The DNA replication–division cycle of eukaryotic cells is controlled by a complex network of regulatory proteins, called cyclin-dependent kinases, and their activators and inhibitors. Although comprehensive and accurate deterministic models of the control system are available for yeast cells, reliable stochastic simulations have not been carried out because the full reaction network has yet to be expressed in terms of elementary reaction steps. As a first step in this direction, we present a simplified version of the control system that is suitable for exact stochastic simulation of intrinsic noise caused by molecular fluctuations and extrinsic noise because of unequal division. The model is consistent with many characteristic features of noisy cell cycle progression in yeast populations, including the observation that mRNAs are present in very low abundance (≈1 mRNA molecule per cell for each expressed gene). For the control system to operate reliably at such low mRNA levels, some specific mRNAs in our model must have very short half-lives (<1 min). If these mRNA molecules are longer-lived (perhaps 2 min), then the intrinsic noise in our simulations is too large, and there must be some additional noise suppression mechanisms at work in cells.
