Nonlinear dynamics of nonsynonymous (dN) and synonymous (dS) substitution rates affects inference of selection.

ABSTRACT: Selection modulates gene sequence evolution in different ways by constraining potential changes of amino acid sequences (purifying selection) or by favoring new and adaptive genetic variants (positive selection). The number of nonsynonymous differences in a pair of protein-coding sequences can be used to quantify the mode and strength of selection. To control for regional variation in substitution rates, the proportionate number of nonsynonymous differences (d(N)) is divided by the proportionate number of synonymous differences (d(S)). The resulting ratio (d(N)/d(S)) is a widely used indicator for functional divergence to identify particular genes that underwent positive selection. With the ever-growing amount of genome data, summary statistics like mean d(N)/d(S) allow gathering informati

SUBMITTER: Wolf JB 

PROVIDER: S-EPMC2817425 | biostudies-literature | 2009 Aug

REPOSITORIES: biostudies-literature