Fig. 3.

Convergent nuclear gene expression in kinetoplastids and dinoflagellates. In both kinetoplastids and dinoflagellates, genes (gray) may be arranged in tandem arrays (Top) that are expressed on a single polycistronic mRNA (Middle). This mRNA is broken into multiple monocistronic mRNAs concomitantly with trans-splicing, which adds a short, capped spliced leader sequence (black) to the 5′ end of all monocistronic mRNAs. In kinetoplastids, the genes (A–C) are arranged randomly and are functionally unrelated, but, in dinoflagellates, the coding sequences on a single polycistronic mRNA are tandem repeats of one gene.