Extensive flagellar remodeling during the complex life cycle of <i>Paratrypanosoma</i> , an early-branching trypanosomatid

Abstract

Significance Kinetoplastids are a group of protists with unique morphology and molecular features. Many have developed a parasitic lifestyle and are economically and medically important causative agents of serious crop, animal, and human diseases. Evolutionarily, Paratrypanosoma confusum sits between parasitic trypanosomatids and free-living bodonids and therefore is uniquely informative for study of the emergence of parasitism. It is morphologically very flexible, as it forms three distinct life stages that can be studied separately. Particularly interesting is the haptomonad stage in which it rebuilds its flagellum into an extensive adhesive plaque. As an adaptation to parasitism, Paratrypanosoma lost a plethora of enzymes involved in breakdown of macromolecules and the capacity of receptor-mediated endocytosis but has gained surface proteins and membrane transporters to obtain nutrients from the host.