Correlation between expression and gene structure. (a) The average intron and exon sizes of the ten most and least expressed genes bearing KEGG Orthology assignments, from A. indica, A.thaliana, O.sativa and V.vinifera are plotted separately for the low and high expression level categories. The error bars indicate standard deviation in the intron and exon sizes respectively. These sizes were obtained from gene structures provided by PASA assemblies mapping these genes to corresponding genome scaffolds. (b) The gene structures depicting the organization and sizes of exons (boxes) and introns (lines) are represented using the web tool StrDraw, for the above mentioned low (left panel) and high (right panel) transcript expression categories in all species.