title: RNA trans-splicing in flatworms. Analysis of trans-spliced mRNAs and genes in the human parasite, Schistosoma mansoni.
abstract: Characteristics of trans-splicing in Schistosoma mansoni were examined to explore the significance and determinants of spliced leader (SL) addition in flatworms. Only a small subset of mRNAs acquire the SL. Analysis of 30 trans-spliced mRNAs and four genes revealed no discernable patterns or common characteristics in the genes, mRNAs, or their encoded proteins that might explain the functional significance of SL addition. While the mRNA encoding the glycolytic enzyme enolase is trans-spliced, mRNAs encoding four other glycolytic enzymes are not, indicating trans-splicing is not prevalent throughout this metabolic pathway. Although the 3' end of flatworm SLs contribute an AUG to mRNAs, the SL AUG does not typically serve to provide a methionine for translation initiation of reading frames in recipient mRNAs. SL RNA expression exhibits no apparent sex, tissue, or cell specificity. Trans-spliced genes undergo both cis- and trans-splicing, and the sequence contexts for these respective acceptor sites are very similar. These results suggest trans-splicing in flatworms is most likely associated either with some property conferred on recipient mRNAs by SL addition or related to some characteristic of the primary transcripts or transcription of trans-spliced genes.
authors.affiliation: Department of Biology, San Francisco State University, California 94132, USA.
authors.forename: R E
authors.initials: RE
authors.lastname: Davis
authors.forename: C
authors.initials: C
authors.lastname: Hardwick
authors.forename: P
authors.initials: P
authors.lastname: Tavernier
authors.forename: S
authors.initials: S
authors.lastname: Hodgson
authors.forename: H
authors.initials: H
authors.lastname: Singh
mesh_terms: D000818:Animals; D001483:Base Sequence; D016384:Consensus Sequence; D017931:DNA Primers; D018076:DNA, Complementary; D015723:Gene Library; D017125:Genes, Protozoan; D006019:Glycolysis; D006801:Humans; D006903:Hydroxymethylglutaryl CoA Reductases / Q000096:biosynthesis; D017403:In Situ Hybridization; D007438:Introns; D008565:Membrane Proteins / Q000096:biosynthesis; D051379:Mice; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000096:biosynthesis; D010751:Phosphopyruvate Hydratase / Q000096:biosynthesis; D016133:Polymerase Chain Reaction; D021382:Protein Sorting Signals / Q000378:metabolism; D050683:R-SNARE Proteins; D012326:RNA Splicing; D012333:RNA, Messenger / Q000096:biosynthesis* / Q000302:isolation & purification; D016053:RNA, Protozoan / Q000096:biosynthesis* / Q000302:isolation & purification; D012550:Schistosoma mansoni / Q000235:genetics / Q000378:metabolism*
chemical_list: D017931:DNA Primers; D018076:DNA, Complementary; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D021382:Protein Sorting Signals; D050683:R-SNARE Proteins; D012333:RNA, Messenger; D016053:RNA, Protozoan; D006903:Hydroxymethylglutaryl CoA Reductases; D010751:Phosphopyruvate Hydratase