Molecular Evolution Activities
 

This is a comprehensive bibliography (under construction) of primary and secondary sources on the neutral theory of molecular evolution. It currently covers the period 1973-2001.

Author :

Sharp, P. M.

Year :

1991

Title :

Determinants of DNA-Sequence Divergence between Escherichia- Coli and Salmonella-Typhimurium - Codon Usage, Map Position, and Concerted Evolution

Journal :

Journal of Molecular Evolution

Volume :

33

Issue :

1

Pages :

23-33

Date :

Jul

Short Title :

Determinants of DNA-Sequence Divergence between Escherichia- Coli and Salmonella-Typhimurium - Codon

Alternate Journal :

J. Mol. Evol.

Custom 2 :

ISI:A1991FT88000005

Abstract :

The nature and extent of DNA sequence divergence between homologous protein-coding genes from Escherichia coli and Salmonella typhimurium have been examined. The degree of divergence varies greatly among genes at both synonymous (silent) and nonsynonymous sites. Much of the variation in silent substitution rates can be explained by natural selection on synonymous codon usage, varying in intensity with gene expression level. Silent substitution rates also vary significantly with chromosomal location, with genes near oriC having lower divergence. Certain genes have been examined in more detail. In particular, the duplicate genes encoding elongation factor Tu, tufA and tufB, from S. typhimurium have been compared to their E. coli homologues. As expected these very highly expressed genes have high codon usage bias and have diverged very little between the two species. Interestingly, these genes, which are widely spaced on the bacterial chromosome, also appear to be undergoing concerted evolution, i.e., there has been exchange between the loci subsequent to the divergence of the two species.

Notes :

Times Cited: 105 FT880 J MOL EVOL
 -- contributed by John Beatty, March 29, 2002