The Brachypodium (Poacea) genus is a useful model system for studying grass genome organisation. Its key representative B. distachyon is well characterised at the cytogenetic and genomic level, unlike other Brachypodium species such as B. stacei and B. hybridum.
Using comparative chromosome mapping with B. distachyon-originated BAC-based probes, Lusinska et al. identify individual chromosomes of B. stacei and B. hybridum. They also demonstrate various and complex rearrangements including nested chromosome fusions and Robertsonian rearrangements, which shaped the B. stacei and B. hybridum karyotypes in terms of their chromosome number and structure.