Evolutionary rate variation, genomic dominance and duplicate gene expression evolution during allotetraploid cotton speciation
Article first published online: 30 NOV 2009
© The Authors (2009). Journal compilation © New Phytologist Trust (2009)
Special Issue: Plant polyploidy
Volume 186, Issue 1, pages 184–193, April 2010
How to Cite
Flagel, L. E. and Wendel, J. F. (2010), Evolutionary rate variation, genomic dominance and duplicate gene expression evolution during allotetraploid cotton speciation. New Phytologist, 186: 184–193. doi: 10.1111/j.1469-8137.2009.03107.x
- Issue published online: 3 MAR 2010
- Article first published online: 30 NOV 2009
- Received: 30 August 2009, Accepted: 11 October 2009
- gene expression;
- Gossypium (cotton);
- •Here, we describe the evolution of gene expression among a diversified cohort of five allopolyploid species in the cotton genus (Gossypium). Using this phylogenetic framework and comparisons with expression changes accompanying F1 hybridization, we provide a temporal perspective on expression diversification following a shared genome duplication.
- •Global patterns of gene expression were studied by the hybridization of petal RNAs to a custom microarray. This platform measures total expression for c. 42 000 duplicated genes, and genome-specific expression for c. 1400 homoeologs (genes duplicated by polyploidy).
- •We report homoeolog expression bias favoring the allopolyploid D genome over the A genome in all species (among five polyploid species, D biases ranging from c. 54 to 60%), in addition to conservation of biases among genes. Furthermore, we find surprising levels of transgressive up- and down-regulation in the allopolyploids, a diminution of the level of bias in genomic expression dominance but not in its magnitude, and high levels of rate variation among allotetraploid species.
- •We illustrate how phylogenetic and temporal components of expression evolution may be partitioned and revealed following allopolyploidy. Overall patterns of expression evolution are similar among the Gossypium allotetraploids, notwithstanding a high level of interspecific rate variation, but differ strikingly from the direction of genomic expression dominance patterns in the synthetic F1 hybrid.