The aim of this research is to determine the three-dimensional structure of the native intact eukaryotic flagellum and of the major components participating in its motion. This will be done by reconstruction from low dose electron micrographs of hydrated, unfixed, unstained, unshadowed, intact flagella, trapped in their native state by ultra-rapid freezing in thin layers of amorphous ice. Many of the movements and rearrangements that occur within cells utlize microtubule-based motors. Imprtant examples include the movement of chromosomes during cell division, and the transport of materials from the cell body of neurons to their distant termini. Little is known of the mechanism of any microtubule-based motile process, even in the case of its most highly organized manifestation, eukaryotic flagella. At present, the structure of these microtubule based motors is not known well enough to suport hypotheses about possible mechanisms. This research will greatly extend our knowledge of ciliary and flagellar structure and provide an insight into the mechanisms of their movement, as well as the structural basis for other microtubule dependent movement such as chromosome separation and vesicle transport in nerve.
