Figure 3.

Relationship between CBI and expression level in ASEs of Dscam exon 6. Relationship between codon usage and the relative order of expression level (splicing frequency) of the D. melanogaster Dscam exon 6 ASEs in hemocyte-derived S2 cell lines [43]. Relationship between the expression level and the difference in CBI between the 5' intron-exon boundary plus central regions and the 3' intron-exon boundary regions (Δ-CBI_{rest – 3'boundary}; A), that between the expression level and CBI in the 5' intron-exon boundary plus central regions (CBI_{5'boundary + central}; B), and that between the expression level and CBI in the 3' intron-exon boundary regions (CBI_3'boundary; C). A positive correlation was detected between the expression level and Δ-CBI_{rest – 3'boundary} (r = 0.33, P < 0.05, Spearman's rank order correlation; N = 46), and between the expression level and CBI_{5'boundary + central} (r = 0.34, P < 0.05, Spearman's rank order correlation; N = 46). No significant correlation was detected between the expression level and CBI_3'boundary (r = -0.11, P = 0.45, Spearman's rank order correlation; N = 46). Arrowhead indicates an outlier > 3 × S. D.