Relationship between movement and aggregation of centrioles in syncytia and formation of microtubule bundles.

Abstract

Evidence suggests that microtubules and 10 nm filaments serve both cytoskeletal and force-generating functions in the intracellular movement and positioning of nuclei in syncytia. During the process of [baby hamster kidney BHK21-F] cell fusion and nuclear migration in syncytia, induced by the paramyxovirus simian virus 5, centrioles are transported in the cytoplasm and form large aggregates. These aggregates are usually found in regions adjacent to rows of aligned nuclei and large bundles of microtubules and 10 nm filaments. Colchicine prevents the translocation and aggregation of centrioles, but cytochalasin B has little effect on this process. The same cytoskeletal elements that are involved in nuclear migration and positioning, i.e., microtubules and 10 nm filaments, are apparently also involved in the transport of centrioles. The possibility that aggregates of centrioles may serve as centers for the organization of microtubules and 10 nm filaments into the large bundles observed in the syncytia is discussed.