Trans-splicing

Trans‐splicing is the joining together of portions of two separate pre‐mRNA molecules. The two distinct categories of spliceosomal trans‐splicing are genic trans‐splicing, which joins exons of different pre‐mRNA transcripts, and spliced leader (SL) trans‐splicing, which involves an exon donated from a specialized SL RNA. Both depend primarily on the same signals and components as cis‐splicing. Genic trans‐splicing events producing protein‐coding mRNAs have been described in a variety of organisms, including Caenorhabditis elegans and Drosophila. In mammalian cells, genic trans‐splicing can be associated with cancers and translocations. SL trans‐splicing has mainly been studied in nematodes and trypanosomes, but there are now numerous and diverse phyla (including primitive chordates) where this type of trans‐splicing has been detected. Such diversity raises questions as to the evolutionary origin of the process. Another intriguing question concerns the function of trans‐splicing, as operon resolution can only account for a small proportion of the total amount of SL trans‐splicing. WIREs RNA 2011 2 417–434 DOI: 10.1002/wrna.71 This article is categorized under: RNA Processing > Splicing Mechanisms RNA Processing > Splicing Regulation/Alternative Splicing