Whole-genome sequencing of multiple Arabidopsis thaliana populations

Detlef Weigel and colleagues report results from the first phase of the Arabidopsis 1001 Genomes Project, based on short-read sequencing of 80 geographically diverse strains. This collection of strains has been made available to the scientific community, and the authors show that the identified polymorphisms in these strains can be useful for imputation and genome-wide association studies. The plant Arabidopsis thaliana occurs naturally in many different habitats throughout Eurasia. As a foundation for identifying genetic variation contributing to adaptation to diverse environments, a 1001 Genomes Project to sequence geographically diverse A. thaliana strains has been initiated. Here we present the first phase of this project, based on population-scale sequencing of 80 strains drawn from eight regions throughout the species' native range. We describe the majority of common small-scale polymorphisms as well as many larger insertions and deletions in the A. thaliana pan-genome, their effects on gene function, and the patterns of local and global linkage among these variants. The action of processes other than spontaneous mutation is identified by comparing the spectrum of mutations that have accumulated since A. thaliana diverged from its closest relative 10 million years ago with the spectrum observed in the laboratory. Recent species-wide selective sweeps are rare, and potentially deleterious mutations are more common in marginal populations.