Characterization of -spliced chimeric RNAs: insights into the mechanism of -splicing.

-splicing is a post-transcriptional processing event that joins exons from separate RNAs to produce a chimeric RNA. However, the detailed mechanism of -splicing remains poorly understood. Here, we characterize -spliced genes and provide insights into the mechanism of -splicing in the tunicate . Tunicates are the closest invertebrates to humans, and their genes frequently undergo -splicing. Our analysis revealed that, in genes that give rise to both -spliced and non--spliced messenger RNAs, -splice acceptor sites were preferentially located at the first functional acceptor site, and their paired donor sites were weak in both and humans. Additionally, we found that -spliced genes had GU- and AU-rich 5' transcribed regions. Our data and findings not only are useful for research community, but may also aid in a better understanding of the -splicing mechanism, potentially advancing the development of gene therapy based on -splicing.