This phenomenon can be exploited for molecular therapy to address mutated gene products.
[4][5] Spliced leader (SL) trans-splicing is used by certain microorganisms, notably protists of the Kinetoplastea class to express genes.
[7] These early-diverging eukaryotes use few introns, and the spliceosome they possess show some unusual variations in their structure assembly.
[9] The spliced leader sequence is highly conserved in lower species that undergo trans-splicing.
[10] Some other eukaryotes, notably among dinoflagellates, sponges, nematodes, cnidarians, ctenophores, flatworms, crustaceans, chaetognaths, rotifers, and tunicates also use more or less frequently the SL trans-splicing.
[12] The SL trans-splicing functions in the resolution of polycistronic transcripts of operons into individual 5'-capped mRNAs.
This processing is achieved when the outrons are trans-spliced to unpaired, downstream acceptor sites adjacent to cistron open reading frames.