title: mRNA 5'-leader trans-splicing in the chordates.
abstract: We report the discovery of mRNA 5'-leader trans-splicing (SL trans-splicing) in the chordates. In the ascidian protochordate Ciona intestinalis, the mRNAs of at least seven genes undergo trans-splicing of a 16-nucleotide 5'-leader apparently derived from a 46-nucleotide RNA that shares features with previously characterized splice donor SL RNAs. SL trans-splicing was known previously to occur in several protist and metazoan phyla, however, this is the first report of SL trans-splicing within the deuterostome division of the metazoa. SL trans-splicing is not known to occur in the vertebrates. However, because ascidians are primitive chordates related to vertebrate ancestors, our findings raise the possibility of ancestral SL trans-splicing in the vertebrate lineage.
authors.affiliation: Montreal Neurological Institute and Biology Department, McGill University, Montreal, Quebec, Canada H3A 2B4.
authors.forename: A E
authors.initials: AE
authors.lastname: Vandenberghe
authors.forename: T H
authors.initials: TH
authors.lastname: Meedel
authors.forename: K E
authors.initials: KE
authors.lastname: Hastings
mesh_terms: D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D002678:Chimera; D002938:Ciona intestinalis / Q000235:genetics*; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D011401:Promoter Regions, Genetic / Q000502:physiology; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism*; D020038:RNA, Spliced Leader / Q000737:chemistry; D020040:Trans-Splicing; D001616:beta-Galactosidase / Q000235:genetics
chemical_list: D012333:RNA, Messenger; D020038:RNA, Spliced Leader; D001616:beta-Galactosidase