Plant conserved non-coding sequences and paralogue evolution.
Genome duplication is a powerful evolutionary force and is arguably most prominent in plants, where several ancient whole-genome duplication events have been documented. Models of gene evolution predict that functional divergence between duplicates (subfunctionalization) is caused by the loss of regulatory elements. Studies of conserved non-coding sequences (CNSs), which are putative regulatory elements, indicate that plants have far fewer CNSs per gene than mammals, suggesting that plants have less complex regulatory mechanisms. Furthermore, a recent study of a duplicated gene pair in maize suggests that CNSs are lost in a complementary fashion, perhaps driving subfunctionalization. If subfunctionalization is common, one expects duplicate genes to diverge in expression; recent microarray analyses in Arabidopsis thalinia suggest that this is the case. Plant genomes are relatively complex on a genomic level because of the prevalence of whole-genome duplication and, paradoxically, subfunctionalization after duplication can lead to relatively simple regulatory regions on a per gene basis.
Lockton
Steven
S
Department of Ecology and Evolution, University of California, Irvine, CA 92697, USA.
Gaut
Brandon S
BS
D001483:Base Sequence; D017124:Conserved Sequence; D019143:Evolution, Molecular; D010802:Phylogeny; D010944:Plants / Q000145:classification / Q000235:genetics*