454 sequencing pools of barcoded BAC clones to survey the gene space of the barley genome

Genome size and complexity hampered so far sequencing the barley genome by imposing too high costs. After introduction of second generation sequencing technology decreasing sequencing costs per base pair were realized providing also new possibilities for large and complex crop genome sequencing. We tested the suitability of the Roche/454 pyrosequencing platform for pooled sequencing of barcoded BAC clones. About 3000 BACclones were selected based on pre-existing information about the presence of at least one contained gene. Further 500 BACs were selected at random providing an independent and unbiased reference set. All BACs were previously analysed by High Information Content Fingerprinting in frame of a comprehensive study to build a physical map of the barley genome. The entire BAC sequencing survey is expected to deliver gene density and repetitive DNA composition information at genome scale. The contained gene information will be exploited to anchor BACs/contigs to a genetic gene-based marker map of barley.