Bragg Jason G, Wagner Andreas
Biology Department, University of New Mexico, Albuquerque, NM 87131, USA.
Trends Genet. 2009 Jan;25(1):5-8. doi: 10.1016/j.tig.2008.10.007. Epub 2008 Nov 17.
The process of gene expression has material costs caused by the quantities of carbon, nitrogen, sulfur and phosphorus that are needed to make mRNAs and proteins. When any such chemical element is ecologically limiting, mutations increasing these costs can reduce growth. Here, we ask if such mutations are 'visible' to natural selection in the yeast Saccharomyces cerevisiae. We find that mutations causing small increases in expression and even single amino acid replacements can be subject to natural selection on the basis of their material costs.
基因表达过程存在物质成本，这是由制造信使核糖核酸（mRNA）和蛋白质所需的碳、氮、硫和磷的量所导致的。当任何一种此类化学元素在生态上受到限制时，增加这些成本的突变会降低生长速度。在此，我们探究此类突变在酿酒酵母中是否能被自然选择“识别”。我们发现，导致表达小幅增加的突变，甚至单个氨基酸替换，都可能因其物质成本而受到自然选择。
