title: Doubling genome size without polyploidization: dynamics of retrotransposition-driven genomic expansions in Oryza australiensis, a wild relative of rice.
abstract: Retrotransposons are the main components of eukaryotic genomes, representing up to 80% of some large plant genomes. These mobile elements transpose via a "copy and paste" mechanism, thus increasing their copy number while active. Their accumulation is now accepted as the main factor of genome size increase in higher eukaryotes, besides polyploidy. However, the dynamics of this process are poorly understood. In this study, we show that Oryza australiensis, a wild relative of the Asian cultivated rice O. sativa, has undergone recent bursts of three LTR-retrotransposon families. This genome has accumulated more than 90,000 retrotransposon copies during the last three million years, leading to a rapid twofold increase of its size. In addition, phenetic analyses of these retrotransposons clearly confirm that the genomic bursts occurred posterior to the radiation of the species. This provides direct evidence of retrotransposon-mediated variation of genome size within a plant genus.
authors.affiliation: Laboratoire Génome et Développement des Plantes, UMR 5096 CNRS-IRD, Université de Perpignan, Perpignan 66860, France.
authors.forename: Benoit
authors.initials: B
authors.lastname: Piegu
authors.forename: Romain
authors.initials: R
authors.lastname: Guyot
authors.forename: Nathalie
authors.initials: N
authors.lastname: Picault
authors.forename: Anne
authors.initials: A
authors.lastname: Roulin
authors.forename: Abhijit
authors.initials: A
authors.lastname: Sanyal
authors.forename: Abhijit
authors.initials: A
authors.lastname: Saniyal
authors.forename: Hyeran
authors.initials: H
authors.lastname: Kim
authors.forename: Kristi
authors.initials: K
authors.lastname: Collura
authors.forename: Darshan S
authors.initials: DS
authors.lastname: Brar
authors.forename: Scott
authors.initials: S
authors.lastname: Jackson
authors.forename: Rod A
authors.initials: RA
authors.lastname: Wing
authors.forename: Olivier
authors.initials: O
authors.lastname: Panaud
mesh_terms: D001483:Base Sequence; D015139:Blotting, Southern; D002874:Chromosome Mapping; D022202:Chromosomes, Artificial, Bacterial; D016000:Cluster Analysis; D020440:Gene Duplication; D018745:Genome, Plant / Q000235:genetics*; D008969:Molecular Sequence Data; D012275:Oryza / Q000235:genetics*; D010802:Phylogeny; D018626:Retroelements / Q000235:genetics*; D017422:Sequence Analysis, DNA
chemical_list: D018626:Retroelements