| Speaker: | Nathan R. Hutchings (Biology, Northwestern State University, Natchitoches, Louisiana) | |||
| Title: | Quantitative properties of trypanosome cell motility. |
| Abstract: |
The African trypanosome, Trypanosoma brucei sp, utilizes a single flagellum to create an auger-like swimming motion. The trypanosome flagellum is tightly sutured along the length of the dirigible-like cell body. Unlike organisms with free flagella, propagating flagellar bends combine with oscillations in the anterior end of the trypanosome cell body to propel the cell along a 3-dimensional helical path in the direction of the free-end of the flagellum. We have utilized digital video microscopy to (1) quantify trypanosome swimming properties at various growth stages, (2) quantify and describe trypanosome flagellar bend shapes, and (3) identify cation concentrations that alter trypanosome flagellar dynamics. Our results indicate that although trypanosome flagellar bends have a wide range of amplitudes and wavelengths, a simple empirical equation accurately describes trypanosome flagellar bend shapes. To assess the dynamics of trypanosome flagellar bends, we have identified behavioral differences between cells at different growth stages, and we have observed changes in flagellar dynamics between cells treated with different concentrations of cations. Interestingly, calcium ions inhibit trypanosome flagellar motility in vivo yet stimulate flagellar motility in vitro. In conjunction with a novel mathematical formalism (based on the differential geometry of curves) to measure arbitrary filament shifting within a filament bundle, we plan to utilize parameters derived from our experimental observations to model and deepen our understanding of trypanosome cell motility.
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