The complex genome organization and large genome size has delayed the development of a reference grass genome sequence. The GenomeZipper, a novel approach incorporating cytogenetics, next generation sequencing and bioinformatics to systematically exploit synteny with the model grasses Brachypodium, rice and sorghum, was recently used in barley to establish a genome-wide putative linear gene index of the barley genome (Mayer et al. 2011).
For forage and turf grass species, the development of tools and resourced to conduct genomic research has so far lagged behind major cereal crop species and genome sequences have yet to be established. Targeted use of grass genome resources allows to assign 3,315 previously unmapped perennial ryegrass genes to individual chromosomes. Based on a transcriptome map the perennial ryegrass GenomeZipper integrates gene indices of Brachypodium, rice and sorghum as well as barley fl-cDNAs in a conserved synteny model and assemble 4,035 conserved grass gene loci. The seven GenomeZipper files provide information-rich scaffolds that anchor in silico a collection of perennial ryegrass genes to their predicted position within the genome.