Reconstruction of evolutionary trajectories of chromosomes unraveled independent genomic repatterning between Triticeae and Brachypodium

摘要

BackgroundAfter polyploidization, a genome may experience large-scale genome-repatterning, featuring wide-spread DNA rearrangement and loss, and often chromosome number reduction. Grasses share a common tetraploidization, after which the originally doubled chromosome numbers reduced to different chromosome numbers among them. A telomere-centric reduction model was proposed previously to explain chromosome number reduction. With Brachpodium as an intermediate linking different major lineages of grasses and a model plant of the Pooideae plants, we wonder whether it mediated the evolution from ancestral grass karyotype to Triticeae karyotype.