Back to Search Start Over

Selection on amino acid substitutions in Arabidopsis.

Authors :
Foxe JP
Dar VU
Zheng H
Nordborg M
Gaut BS
Wright SI
Source :
Molecular biology and evolution [Mol Biol Evol] 2008 Jul; Vol. 25 (7), pp. 1375-83. Date of Electronic Publication: 2008 Apr 04.
Publication Year :
2008

Abstract

Studies of nucleotide diversity have found an excess of low-frequency amino acid polymorphisms segregating in Arabidopsis thaliana, suggesting a predominance of weak purifying selection acting on amino acid polymorphism in this inbreeding species. Here, we investigate levels of diversity and divergence at synonymous and nonsynonymous sites in 6 circumpolar populations of the outbreeding Arabidopsis lyrata and compare these results with A. thaliana, to test for differences in mutation and selection parameters across genes, populations, and species. We find that A. lyrata shows an excess of low-frequency nonsynonymous polymorphisms both within populations and species wide, consistent with weak purifying selection similar to the patterns observed in A. thaliana. Furthermore, nonsynonymous polymorphisms tend to be more restricted in their population distribution in A. lyrata, consistent with purifying selection preventing their geographic spread. Highly expressed genes show a reduced ratio of amino acid to synonymous change for both polymorphism and fixed differences, suggesting a general pattern of stronger purifying selection on high-expression proteins.

Details

Language :
English
ISSN :
1537-1719
Volume :
25
Issue :
7
Database :
MEDLINE
Journal :
Molecular biology and evolution
Publication Type :
Academic Journal
Accession number :
18390851
Full Text :
https://doi.org/10.1093/molbev/msn079