Evidence for an ancient whole-genome duplication event in rice and other cereals.
Gene duplication has been proposed as an accelerator of evolution. Ancient genome duplication events have been identified in diverse organisms, such as yeast, vertebrates, and Arabidopsis. Here, we have identified a whole genome duplication event (WGD) in the rice genome, which took place prior to the divergence of grasses about 70 million years ago (mya). A total of 117 duplicated blocks were detected, which are distributed on all 12 chromosomes and cover about 60% of the rice genome. About 20% genes on these duplicated segments are retained as duplicate pairs. In contrast, 60% of the transcription factor genes are retained as duplicates. The identification of a WGD in the ancestral grass genome will impact the study of grass genome evolution, and suggest that polyploidization and subsequent gene losses and chromosomal rearrangements have played an important role in the diversification of grasses.
Tian
Chao-Guang
CG
Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
Xiong
Yu-Qing
YQ
Liu
Tie-Yan
TY
Sun
Shou-Hong
SH
Chen
Liang-Biao
LB
Chen
Ming-Sheng
MS
D002523:Edible Grain / Q000235:genetics*; D019143:Evolution, Molecular; D020440:Gene Duplication; D017343:Genes, Plant / Q000235:genetics; D018745:Genome, Plant; D008957:Models, Genetic; D012275:Oryza / Q000235:genetics*; D010802:Phylogeny; D011123:Polyploidy; D013997:Time Factors