| wide variety of eukaryotic cells are able to propel themselves through a liquid medium as a consequence of ciliary activity. The ciliary axoneme, with its associated basal bodies and rootlets, forms a complex motile apparatus. The assembly of this motile apparatus is a developmental event that is usually difficult to study because in most organisms it is localized to relatively few cells where it occurs asynchronously. The work presented in this dissertation uses spermiogenesis in the water fern, Marsilea vestita, as a model to investigate some aspects of the assembly of a motile apparatus. Spermiogenesis in M. vestita occurs rapidly and synchronously after initiating the developmental program by placing dry microspores into an aqueous medium. Several approaches demonstrate that most of the proteins required for this process are synthesized, and stored in the dry microspore prior to differentiation. Furthermore, most of the proteins that are newly synthesized are translated from mRNA stored in the dry microspore. This mechanism of regulation appears to underlie the rapid differentiation of spermatids into mature spermatozoids. Western blot analysis demonstrates that... |
