Ribbon worms are members of a taxonomic group (phylum Nemertea) for which little information regarding gene structure is available. This study looked at intron number, intron length, intron position, and intron/exon junctions for the introns of eight genes from the milky ribbon worm, Cerebratulus lacteus. A total of 22 introns were present in the eight genes, averaging approximately 1200 base pairs in length. All intron/exon junctions contained consensus splice site sequences. Intron placement in these eight nemertean genes was compared to introns in homologous counterparts of other species. There were numerous cases where an intron from C. lacteus shared the same position and phase with introns from homologous genes in various other animals, including vertebrates. There was one case where an intron from C. lacteus shared the same position and phase with introns from homologous genes in an assortment of organisms, including vertebrates,other invertebrates, and higher plants.
Research highlights: Eight genes in the nemertean C. lacteus contain an average of 2.75 introns Eight genes in C. lacteus have introns with an average length of 1200 base pairs Twenty-two introns in C. lacteus all contain consensus splice sites Nemertean intron position and phase are often found to be conserved across kingdoms