Across-paralog comparison of the exon patterns for Cpeb2. The numbers represent the lengths of exons in a sequential order. The locations and size of exons were determined by aligning the cDNA sequence to the genomic sequence. For simplicity, only one RefSeq sequence is used for each organism. The pattern in C. elegans is not consistent with those in the vertebrates. However the patterns among the vertebrates are highly conserved. The asterisks represent the variable regions of ±90-nt and ±24-nt discussed in the text, which would subsequently lead to 30-aa and 8-aa deletion or insertion. The pound sign indicates a newly updated isoform in which the use of an alternative exon leads to an extralong protein.