The corresponding P. marinus genomic sequences of 39 and 29 full-length cDNAs from P. marinus and P. chesapeaki, respectively [8] , [14] , were obtained. Comparison of these 68 cDNAs with the genomic DNA sequences revealed the presence of introns in 42 genes, yielding a 61.8% intron rate. Through GenBank database searches, we obtained an additional 36 common genes with known genomic structures, 30 of which have intron(s) (Table S1 ). Overall, the intron rate for P. marinus genes was 69.2% (72 out of 104). The intron-containing genes harbored between one and ten introns with the lengths ranging from 39 to 1622 bp, the majority of which were ,100 bp.