Worms reveal intron insights

Irish researchers have discovered 122 novel introns that appeared in the genomes of Caenorhabditis elegans and Caenorhabditis briggsae since the two species diverged 80 to 120 million years ago, shedding light on how new introns arise and are subsequently spread among genes.

The genomes of both worms contain roughly 100,000 introns, of which more than 6000 are unique to one species or the other. Kenneth Wolfe and Avril Coghlan identified 81 new introns in C. elegans and 41 new introns in C. briggsae. Of these, 13 are found in genes implicated in premRNA processing, the authors report in the June 28 PNAS early online edition.

"We used BLAST [Basic Local Alignment Search Tool] to identify orthologous genes across all the species (animal and nematode), and by comparison of all genes, we were able to find intron sites present in one of the nematodes, but absent in all other species," Wolfe, ...