Dynein-related polypeptides in pollen and pollen tubes

Microtubules in pollen tubes are evident within the vegetative and generative cell cytoplasm. This observation led to the formulation of several hypotheses regarding the role of microtubules in cytoplasmic movement and the migration of the vegetative nucleus/generative cell along the pollen tube. The study of microtubular motor proteins in pollen tubes followed the discovery and characterization of an immunoreactive homolog of mammalian kinesin in tobacco pollen tubes. Recent identification of dynein-related polypeptides in pollen tubes of Nicotiana tabacum and pollen of Ginkgo biloba is a significant step in the definition of the role of microtubule function within pollen and pollen tubes.