U12-type introns are spliced by the U12-dependent spliceosome and are present in the genomes of many higher eukaryotic lineages including plants, chordates and some invertebrates. The resource described here, the U12 Intron Database (U12DB), aims to catalog the U12-type introns of completely sequenced eukaryotic genomes in a framework that groups orthologous introns with each other. This will aid further investigations into the evolution and mechanism of U12-dependent splicing as well as assist ongoing genome annotation efforts. Public access to the U12 Intron Database is available at http://genome.crg.es/cgi-bin/u12db/u12db.cgi.
nucleic acid sequence gene structure, introns and exons, splice sites