Figure 2

Regional differences in codon usage pattern among ASEs of Dscam. Relationship between the codon bias indices (CBI) of the center and the intron-exon boundary regions (15 full codons from the junction) among the ASEs of D. melanogaster Dscam exon 4 (A), among those of exon 6 (B), and among those of exon 9 (C). Those among other internal coding exons longer than 135 bp (exon 3, 5, 7, 8, 11–16, 17.1, 17.2, 18–22) are also shown (D). Closed and open circles indicate 5' and 3' boundary regions, respectively.