Across-paralog comparison of the exon patterns for Cpeb4. 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 patterns among the vertebrates are highly conserved. The asterisks * represent the variable regions of ±51-nt and ±24-nt discussed in the text, which would subsequently lead to 17-aa and 8-aa deletion or insertion. The question mark indicates that the size of the exon was unknown due to missing information in the genomic sequence. As a result, the alignment of the exons in grey to this map is uncertain.