Lehner Ben
EMBL-CRG Systems Biology Unit, Barcelona, Spain.
Mol Syst Biol. 2008;4:170. doi: 10.1038/msb.2008.11. Epub 2008 Mar 4.
Gene expression, like many biological processes, is subject to noise. This noise has been measured on a global scale, but its general importance to the fitness of an organism is unclear. Here, I show that noise in gene expression in yeast has evolved to prevent harmful stochastic variation in the levels of genes that reduce fitness when their expression levels change. Therefore, there has probably been widespread selection to minimise noise in gene expression. Selection to minimise noise, because it results in gene expression that is stable to stochastic variation in cellular components, may also constrain the ability of gene expression to respond to non-stochastic variation. I present evidence that this has indeed been the case in yeast. I therefore conclude that gene expression noise is an important biological trait, and one that probably limits the evolvability of complex living systems.
基因表达与许多生物过程一样，容易受到噪声的影响。这种噪声已在全球范围内进行了测量，但其对生物体适应性的普遍重要性尚不清楚。在这里，我表明酵母中基因表达的噪声已经进化，以防止当基因表达水平发生变化时降低适应性的基因水平出现有害的随机变化。因此，可能已经存在广泛的选择以最小化基因表达中的噪声。选择最小化噪声，因为它导致基因表达对细胞成分的随机变化具有稳定性，也可能限制基因表达对非随机变化作出反应的能力。我提供的证据表明酵母中确实如此。因此，我得出结论，基因表达噪声是一种重要的生物学特性，并且可能限制了复杂生命系统的进化能力。
