Experimental approaches to evaluate the contributions of candidate protein-coding mutations to phenotypic evolution.-猫眼课题宝

评估候选蛋白质编码突变对表型进化的贡献的实验方法。

DOI：

10.1007/978-1-61779-228-1_22

发表时间：

2011

期刊：

Methods in molecular biology (Clifton, N.J.)

影响因子：

通讯作者：

中科院分区：

文献类型：

作者：

Storz,JayF;Zera,AnthonyJ

Identifying mechanisms of molecular adaptation can provide important insights into the process of phenotypic evolution, but it can be exceedingly difficult to quantify the phenotypic effects of specific mutational changes. To verify the adaptive significance of genetically based changes in protein function, it is necessary to document functional differences between the products of derived and wild-type alleles and to demonstrate that such differences impinge on higher-level physiological processes (and ultimately, fitness). In the case of metabolic enzymes, this requires documenting in vivo differences in reaction rate that give rise to differences in flux through the pathway in which the enzymes function. These measured differences in pathway flux should then give rise to differences in cellular or systemic physiology that affect fitness-related variation in whole-organism performance. Efforts to establish these causal connections between genotype, phenotype, and fitness require experiments that carefully control for environmental variation and background genetic variation. Here, we discuss experimental approaches to evaluate the contributions of amino-acid mutations to adaptive phenotypic change. We discuss conceptual and methodological issues associated with in vitro and in vivo studies of protein function, and the evolutionary insights that can be gleaned from such studies. We also discuss the importance of isolating the effects of individual mutations to distinguish between positively selected substitutions that directly contribute to improvements in protein function versus positively selected, compensatory substitutions that mitigate negative pleiotropic effects of antecedent changes.