Biology and mechanism of trypanosome cell motility

Abstract

Flagellum-mediated cell motility has captured the attention and imagination of biologists for more than 300 years (68). Trypanosomes provide an excellent experimental system for studying cell motility. These parasites are easily cultured in semidefined medium, and the ultrastructure of their flagellar apparatus and other cellular structures have been extensively characterized. Importantly, several state-of-the-art tools for molecular genetic manipulation of trypanosomes are now available. In particular, inducible silencing of gene expression via RNAi provides an extremely powerful method for determining the function of essential genes. As discussed above, these approaches have allowed the first glimpse of function for several prominent and enigmatic components of the trypanosome flagellar apparatus. Ongoing genome projects for T. brucei and related kinetoplastid parasites (17) will further enhance the utility of these organisms as experimental systems. In addition to presenting a fascinating biological phenomenon, cell motility plays an important role in the pathogenesis of infectious disease. In the case of trypanosomes and other protozoan pathogens, we are only now beginning to understand the nature of this relationship, and further study of both the biological and mechanistic aspects of cell motility are necessary before we can accurately describe the relationship between parasite and host.