TRANSSPLICING AND POLYCISTRONIC TRANSCRIPTION IN CAENORHABDITIS-ELEGANS

Caenorhabditis elegans engages in three distinct versions of nuclear p re-mRNA splicing: cis-splicing of introns and two kinds of trans-splic ing that result in the addition of two different spliced leaders onto mRNAs. One leader (SL1) is used near the 5' ends of pre-mRNAs while th e other (SL2) is used at internal trans-splice sites of polycistronic pre-mRNAs. Here, I consider bow these three types of splicing event ar e faithfully carried out.