Format

Send to

Choose Destination
Mol Biol Evol. 2010 Aug;27(8):1813-21. doi: 10.1093/molbev/msq062. Epub 2010 Mar 1.

Genome-wide evidence for efficient positive and purifying selection in Capsella grandiflora, a plant species with a large effective population size.

Author information

1
Department of Ecology and Evolutionary Biology, University of Toronto, Toronto, Ontario, Canada. tanja.slotte@ebc.uu.se

Abstract

Recent studies comparing genome-wide polymorphism and divergence in Drosophila have found evidence for a surprisingly high proportion of adaptive amino acid fixations, but results for other taxa are mixed. In particular, few studies have found convincing evidence for adaptive amino acid substitution in plants. To assess the generality of this finding, we have sequenced 257 loci in the outcrossing crucifer Capsella grandiflora, which has a large effective population size and low population structure. Using a new method that jointly infers selective and demographic effects, we estimate that 40% of amino acid substitutions were fixed by positive selection in this species, and we also infer a low proportion of slightly deleterious amino acid mutations. We contrast these estimates with those for a similar data set from the closely related Arabidopsis thaliana and find significantly higher rates of adaptive evolution and fewer nearly neutral mutations in C. grandiflora. In agreement with results for other taxa, genes involved in reproduction show the strongest evidence for positive selection in C. grandiflora. Taken together, these results imply that both positive and purifying selection are more effective in C. grandiflora than in A. thaliana, consistent with the contrasting demographic history and effective population sizes of these species.

PMID:
20194429
DOI:
10.1093/molbev/msq062
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Silverchair Information Systems
Loading ...
Support Center