The genome of Strongylocentrotus purpuratus was among the sequences compared for this study
(Image by Minette Layne/Wikimedia Commons.)
“This experiment recapitulates in vivo the birth of an intron that arose in the ancestral jawed vertebrate lineage nearly half-a-billion years ago,” wrote first author Hellsten and his colleagues in the paper. They noted that early eukaryotic genomes had more introns than modern-day eukaryotic genomes. However, they said, the genome of the water flea Daphnia pulex, that the DOE JGI published earlier this year in Science, contained examples of recently-inserted introns.