Fig 1.
Diagrams of trypanosomatids in their motile and attached forms.
The large dark oval is the nucleus. The small dark disk is the kDNA. Green is the axoneme. Attachment plaques are shown as green lines in attached forms. A detailed description of swimming morphologies can be found in [15]. In monoxenous parasites and Leishmania spp., the attachment plaque forms at the tip of the shortened flagellum. In T. cruzi, the attachment plaque is also found at the tip but the flagellum is only slightly shorter. In T. brucei and T. congolense, the attachment plaque(s) form on the lateral portion of the flagellum.
Fig 2.
Stages of attachment visualized using in vitro systems.
C. fasciculata and P. confusum attach via the base of the flagellum, which then shortens until the cell rests perpendicular to the surface on the flagellar attachment plaque [21,57]. T. congolense trypomastigotes initially attach via the tip of the flagellum. The cell body and flagellum then slide until the cell is resting on the surface connected by a lateral flagellar attachment plaque [62]. L. mexicana can attach via the tip or lateral (shown) portion of the flagellum. A loop sometimes forms between the point of attachment and the cell body. The flagellum then shortens until the haptomonad rests perpendicular to the surface on the flagellar attachment plaque [56].
Table 1.
Gene products with possible roles in trypanosomatid adhesion and attachment.