The new starch biosynthesis pathway reflects one aspect of the impact of WGD on grass evolution.
In , only about 32% of duplicated genes have been retained in sister duplicated regions derived of polyploidy (Blanc et al. The loss and retention of polyploidy-derived duplicated genes are nonrandom and related to function.
In , genes involved in transcriptional regulation and signal transduction have been preferentially retained and genes involved in DNA repair have been preferentially lost (Blanc and Wolfe 2004; Seoighe and Gehring 2004). (2006) found that some gene families have convergent fates in independent WGD events, such as enrichments of myb-like and protein kinase families in plants. However, the evolutionary impact of this WGD has yet to be elucidated.
Here, we analyzed the fate of duplicated genes following the ancient whole-genome duplication (WGD) in rice.
Polyploidy-derived duplicated genes were found to be preferentially lost from one of each pair of duplicated chromosomal segments, suggesting that the asymmetric gene loss may result from transcriptome dominance of the ancestral allotetraploid genome.
Our results suggest that paleopolyploidy was widespread and played an important role in the evolution of rice.