Edinburgh, Scotland, United Kingdom - TAIR

Evidence of neutral transcriptome evolution
in plants
An organism’s transcriptome is its set of gene transcripts (mRNAs) at a defined
spatial and temporal location. Since gene expression is affected markedly by
environmental and developmental perturbations, transcriptome divergence
among taxa will evolve through adaptive phenotypic selection. Here we show
that stochastic, evolutionarily neutral processes also drive transcriptome
divergence in plants. Among 14 Brassicaceae (cabbage family) taxa,
transcriptome divergence correlates positively with evolutionary distance
between taxa and with gene expression diversity within replicate samples.
Remarkably, the transcriptomes of functionally homologous tissues sampled
from different taxa have diverged more than the transcriptomes of functionally
discrete – and highly specialised – tissues from one taxa. These observations
are consistent with neutral evolutionary theories. Analysis at the individual gene
level has been performed using the ‘analysis of trait’ module of the Phylocom
software package, which is designed for the analysis of community phylogenetic
structure and character evolution. This has identified genes whose expression
level is under phylogenetic constraint and ‘Phylogenetic independent contrasts’
have been used in parallel to calculate evolutionary correlations of gene
expression across the Brassicaceae. Correlation analyses can then be used to
infer gene interaction networks that are evolutionary conserved. Web based tools
will be developed to enable users to identify genes that are evolutionary
correlated with their gene of interest.
Broadley et al 2008, New Phytologist: 180, 587-593
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C16
Wednesday 17:30 - 17:45
Tools and Resources
Neil Graham1
Martin Broadley1
Philip White2
John Hammond3
Helen Bowe3
Zoe Emmerson1
Rupert Fray1
Pietro Iannetta2
Jim McNicol2
Sean May1
1University of Nottingham
Loughborough
UK
2SCRI
Dundee
UK
3University of Warwick
Wellesbourne
UK