Gene length and expression level as primary genic properties. (A) Expression level is positively correlated with the number of transcripts. Genes were binned into 160 expression groups (each with 50 genes) and the average number of transcripts is shown for each expression group. (B) Gene length is generally negatively correlated with expression level, but not for mid-range expression level (bounded by dashed lines, see text). (C,D) The landscape of gene length and expression show inverse patterns of gene family sizes and alternative splicing. For each combination of gene length and expression level bins, the average number of gene family size (C) and the average number of transcripts (D) is shown.
