spire; Acts as a actin nucleation factor, remains associated with the slow-growing pointed end of the new filament. Involved in vesicle transport processes providing a novel link between actin organization and intracellular transport. Required for localization of determinants within the developing oocyte to the posterior pole and to the dorsal anterior corner. Links Rho family signaling and Jnk function to the actin cytoskeleton (1020 aa)