Determinants of exon-level evolutionary rates in Arabidopsis species.

What causes the variations in evolutionary rates is fundamental to molecular evolution. However, in plants, the causes of within-gene evolutionary rate variations remain underexplored. Here we use the principal component regression to examine the contributions of eleven exon features to the within-gene variations in nonsynonymous substitution rate (d(N)), synonymous substitution rate (d(S)), and the d(N)/d(S) ratio in Arabidopsis species.