Duplication and DNA segmental loss in the rice genome: implications for diploidization

New Phytol. 2005 Mar;165(3):937-46. doi: 10.1111/j.1469-8137.2004.01293.x.


* Large-scale duplication events have been recently uncovered in the rice genome, but different interpretations were proposed regarding the extent of the duplications. * Through analysing the 370 Mb genome sequences assembled into 12 chromosomes of Oryza sativa subspecies indica, we detected 10 duplicated blocks on all 12 chromosomes that contained 47% of the total predicted genes. Based on the phylogenetic analysis, we inferred that this was a result of a genome duplication that occurred c. 70 million years ago, supporting the polyploidy origin of the rice genome. In addition, a segmental duplication was also identified involving chromosomes 11 and 12, which occurred c. 5 million years ago. * Following the duplications, there have been large-scale chromosomal rearrangements and deletions. About 30-65% of duplicated genes were lost shortly after the duplications, leading to a rapid diploidization. * Together with other lines of evidence, we propose that polyploidization is still an ongoing process in grasses of polyploidy origins.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biological Evolution*
  • Chromosomes, Plant
  • Gene Duplication*
  • Genome, Plant*
  • Oryza / genetics*
  • Ploidies*