On the evolution of codon volatility

Genetics. 2005 Jan;169(1):495-501. doi: 10.1534/genetics.104.034884. Epub 2004 Sep 30.

Abstract

Volatility of a codon is defined as the probability that a random point mutation in the codon generates a nonsynonymous change. It has been proposed that higher-than-expected mean codon volatility of a gene indicates that positive selection for nonsynonymous changes has acted on the gene in the recent past. I show that strong frequency-dependent selection (minority advantage) in large populations can increase codon volatility slightly, whereas directional positive selection has no effect on volatility. Factors unrelated to positive selection, such as expression-related or GC-content-related codon usage bias, also affect volatility. These and other considerations suggest that codon volatility has only limited utility for detecting positive selection at the DNA sequence level.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Base Composition
  • Biological Evolution*
  • Codon / genetics*
  • GC Rich Sequence
  • Genes / genetics*
  • Genome*
  • Humans
  • Mutation / genetics*
  • Selection, Genetic*

Substances

  • Codon