Figure 2.

Average lengths of gene parameters as functions of average expression level category. Total 10,289 genes grouped into 30 categories based on the length parameters, and then the average lengths (transformed to denary logarithm) and average expression levels (p.p.m) for each category were computed. (a) CDS length versus expression level; (b) first intron length versus expression level; (c) average intron length versus expression level; (d) total intron length versus expression level; (e) gene size versus expression level. The relationship between expression level and gene size shows a "Λ-shape". For the decreasing part, gene compactness shows a strong correlation with gene expression level with very high coefficient (P < 0.0001, r = -0.9347). After adjusted values of type I error using a Bonferroni correction for multiple tests, all P-values remain statistically significant. Error bars show ± twice the standard error.