The determination of the structure of the dyneins is of fundamental importance to the understanding of microtubule- mediated motility. This project will identify the structural relationships among the dyneins which are expressed in the gametes and early embryo of a single animal species, the sea urchin, a uniquely well-suited model system. By focussing on a single animal which expresses multiple dyneins in different developmental contexts, information related directly to function and to development will be obtained. Specific aims are to: determine the polypeptide composition of the ca. 21S ciliary dynein which is obtained by the high salt extraction of embryonic cilia; raise new antibodies to ciliary dynein polypeptides; and to determine the structure of the ciliary 12S and 21S dyneins by electron microscopy. The results of these studies will add to our understanding of dynein structual heterogeneity and how it might affect dynein function.
