Leveraging the genome sequences of two Arabidopsis relatives for evolutionary and ecological genomes.

DNA sequences of 49 loci were obtained for samples from 11 European populations of Arabidopsis lyrata and a worldwide A. thaliana sample (11 strains). Diversity for the genes was studied for the first time in A. thaliana populations. Nucleotide diversities estimated from silent sites are much lower in A. thaliana. Genes in pericentromere region do not differ significantly in diversity from chromosome arm region genes, confirming previous unexpected findings.

It is predicted that natural selection will be weak in self-fertilizing species, but the expected difference was not found previously, comparing A. thaliana (selfer) with A. lyrata (outcrosser). Our new analyses with the same two species, plus Capsella rubella (selfer) and C. grandiflora (outcrosser) used extensive data from new DNA sequencing. Our new analyses take biologically important factors into account, making it possible to investigate selection, even if after recent changes in population size. Published in Genome Biology & Evolution.

It is predicted that natural selection will be weak in self-fertilizing species, but the expected difference was not found in previous comparisons of the selfing plant Arabidopsis thaliana with its outcrossing relative A. lyrata. Our new analyses with the same two species, plus Capsella rubella (selfer) and C. grandiflora (outcrosser) used extensive data from new DNA sequencing. We developed new analysis methods that can take biologically important factors into account, including recent changes in population size. Using these methods, we now detect the expected difference in selection.

New DNA sequences from natural populations, and analyses to test an important hypothesis. It is predicted that natural selection will be weak in self-fertilizing species, but the expected difference was not found in previous comparisons of the selfing plant Arabidopsis thaliana with its outcrossing relative A. lyrata. Our new analyses with the same two species, plus Capsella rubella (selfer) and C. grandiflora (outcrosser) used extensive data from new DNA sequencing. We developed new analysis methods that can take biologically important factors into account, including recent changes in population size. Using these methods, we now detect the expected difference in selection.