Genetics. Published Articles Ahead of Print: May 27, 2008, Copyright © 2008
doi:10.1534/genetics.107.085282


A more recent version of this article appeared on June 1, 2008.

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High DNA sequence diversity in pericentromeric genes of the plant Arabidopsis lyrata

Akira Kawabe 1, Alan Forrest 2, Stephen I. Wright 3 and Deborah Charlesworth 2*

1 National Institute of Genetics
2 University of Edinburgh
3 York University

* To whom correspondence should be addressed. E-mail: deborah.charlesworth{at}ed.ac.uk.

Submitted on November 30, 2007
Revised on January 4, 2008
Accepted on 5 April 2008


Abstract

Differences in neutral diversity at different loci are predicted to arise due to differences in mutation rates and from the "hitchhiking" effects of natural selection. Consistent with hitch-hiking models, Drosophila melanogaster chromosome regions with very low recombination have unusually low nucleotide diversity. We compared levels of diversity from five pericentromeric regions with regions of normal recombination in Arabidopsis lyrata, an outcrossing close relative of the highly selfing A. thaliana. In contrast with the accepted theoretical prediction, and the pattern in Drosophila, we found generally high diversity in pericentromeric genes, which is consistent with the observation in A. thaliana. Our data rule out balancing selection in the pericentromeric regions, suggesting that hitch-hiking is more strongly reducing diversity in the chromosome arms than the pericentromere regions.

Key Words: Arabidopsis lyrata, diversity, hitch-hiking, pericentromeric region, recombination