Information contents and correlations of three splice signal motifs. (A) The information contents of 5'ss (blue), 3'ss (red), and BP (green) motifs are measured in bits. Results for only representative species are shown here. Complete numerical data are presented in Additional file 4. (B) Correlation between (a) information contents of 3'ss and 5'ss, (b) information contents of BP and 3'ss, (c) % PPT of all introns and information content of 3'ss, and (d) information contents of BP and 5'ss. 61 species are categorized into six groups, as shown in the legend on the left. The Pearson correlation coefficient and the significance thereof are shown on top of each plot.