High DNA sequence diversity in pericentromeric genes of the plant Arabidopsis lyrata.
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 hitchhiking 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 hitchhiking is more strongly reducing diversity in the chromosome arms than the pericentromere regions.
Kawabe
Akira
A
Institute of Evolutionary Biology, University of Edinburgh, Edinburgh EH9 3JT, United Kingdom.
Forrest
Alan
A
Wright
Stephen I
SI
Charlesworth
Deborah
D
D017360:Arabidopsis / Q000145:classification / Q000235:genetics*; D002503:Centromere / Q000235:genetics; D032461:Chromosomes, Plant / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics*; D017343:Genes, Plant; D014644:Genetic Variation; D005828:Genetics, Population; D016013:Likelihood Functions; D015810:Linkage Disequilibrium; D008957:Models, Genetic; D008969:Molecular Sequence Data; D012641:Selection, Genetic; D013045:Species Specificity
D018744:DNA, Plant