Dinoflagellate ribosomal RNA; an evolutionary relic?

Summary

The apparent molecular weights of the rRNA subunits of the dinoflagellatePeridinium cinctum fa.westii were determined by polyacrylamide gel electrophoresis to obtain an indication of its evolutionary status. The apparent molecular weights of thePeridinium light and heavy rRNA subunits were 0.7 and 1.23 × 10⁶ respectively. The light rRNA is therefore typically eukaryotic but the heavy rRNA has a significantly lower MW than previously reported for higher eukaryotes which range from 1.3 to 1.75 × 10⁶ depending on their evolutionary position. Thus by this criterionPeridinium is similar to red algae and may represent a eukaryotic stage, lower than fungi or green plants.