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Doubling genome size without polyploidization: Dynamics of retrotransposition-driven genomic expansions in Oryza australiensis, a wild relative of rice - 2006 - News
2006 : Doubling genome size without polyploidization: Dynamics of retrotransposition-driven genomic expansions in Oryza australiensis, a wild relative of rice
Posted by webmaster on 2006/10/31 23:50:00 ( 411 reads )

Benoit Piegu,1 Romain Guyot,1 Nathalie Picault,1 Anne Roulin,1 Abhijit Saniyal,3 Hyeran Kim,4 Kristi Collura,4 Darshan S. Brar,2 Scott Jackson,3 Rod A. Wing,4 and Olivier Panaud1,1

Genome Res. 2006 October; 16(10): 1262–1269.
doi: 10.1101/gr.5290206

PMCID: PMC1581435

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.

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Attached Files: OMAP_Piegu_2006.pdf
Sponsors: A portion of AGIs material is based upon work supported by the National Science Foundation under Grant Number 102620