Dynamic Genome Evolution of Oryza——A Genus-Wide Comparative Analysis

摘要

Multi-species comparisons in a phylogenetic context improve the sensitivity and precision of evolutionary inference.The genus Oryza consists of more than 20 species and 10 genome types with a robust phylogeny.Comparative sequence analyses across the genus Oryza in three genomic regions,Adhl,Mocl,and Hdl,have provided insight into the genomic evolution of Oryza species.Studies have revealed the maintenance of high gene colinearity in euchromatic regions.Disruptions of microcolinearity are common,some of which have functional consequences.New genes have been created by de novo mechanisms,transposon mediation,and/or duplication and recombination.In natural allotetraploids,the silencing of duplicated genes can be caused by deletions,frameshifting mutations,nonsense mutations,or epigenetic modifications.Future comparative studies of heterochromatin and centromeres will undoubtedly reveal novel features of these cytologically defined genome components.We propose that newgeneration sequencing will promote whole-chromosome and whole-genome comparative studies in Oryza species in the near future.