AN ULTRASTRUCTURAL COMPARISON OF THE MITOTIC APPARATUS, FEEDING APPARATUS, FLAGELLAR APPARATUS AND CYTOSKELETON IN EUGLENOIDS AND KINETOPLASTIDS

The euglenoids and kinetoplastids form a diverse assemblage of organisms which show no obvious phylogenetic relationship with other flagellates. An ultrastructural examination and comparison of the flagellar apparatus, the feeding apparatus, and mitotic nucleus indicate a number of shared morphological features which support a common ancestry for the two groups. Of particular interest is the euglenoid, Petalomonas cantuscygni, which shares many of the ultrastructural features common to both groups. Based on the data Presented, we hypothesize that a euglenoid with features similar to those now present in P. cantuscygni was ancestral to both the euglenoid and kinetoplastid lines.