title: Sliding of centrosome-unattached microtubules defines key features of neuronal phenotype.
abstract: Contemporary models for neuronal migration are grounded in the view that virtually all functionally relevant microtubules (MTs) in migrating neurons are attached to the centrosome, which occupies a position between the nucleus and a short leading process. It is assumed that MTs do not undergo independent movements but rather transduce forces that enable movements of the centrosome and nucleus. The present results demonstrate that although this is mostly true, a small fraction of the MTs are centrosome-unattached, and this permits limited sliding of MTs. When this sliding is pharmacologically inhibited, the leading process becomes shorter, migration of the neuron deviates from its normal path, and the MTs within the leading process become buckled. Partial depletion of ninein, a protein that attaches MTs to the centrosome, leads to greater numbers of centrosome-unattached MTs as well as greater sliding of MTs. Concomitantly, the soma becomes less mobile and the leading process acquires an elongated morphology akin to an axon.
authors.affiliation: Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129.
authors.forename: Anand N
authors.initials: AN
authors.lastname: Rao
authors.affiliation: Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129.
authors.forename: Aditi
authors.initials: A
authors.lastname: Falnikar
authors.affiliation: Boulder Laboratory for 3D Electron Microscopy of Cells, University of Colorado, Boulder, CO 80309.
authors.forename: Eileen T
authors.initials: ET
authors.lastname: O'Toole
authors.affiliation: Boulder Laboratory for 3D Electron Microscopy of Cells, University of Colorado, Boulder, CO 80309.
authors.forename: Mary K
authors.initials: MK
authors.lastname: Morphew
authors.affiliation: Boulder Laboratory for 3D Electron Microscopy of Cells, University of Colorado, Boulder, CO 80309.
authors.forename: Andreas
authors.initials: A
authors.lastname: Hoenger
authors.affiliation: National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32310 Department of Biological Science, Florida State University, Tallahassee, FL 32310.
authors.forename: Michael W
authors.initials: MW
authors.lastname: Davidson
authors.affiliation: Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129.
authors.forename: Xiaobing
authors.initials: X
authors.lastname: Yuan
authors.affiliation: Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA 19129 pbaas@drexelmed.edu.
authors.forename: Peter W
authors.initials: PW
authors.lastname: Baas
mesh_terms: D000818:Animals; D002465:Cell Movement / Q000502:physiology; D018385:Centrosome / Q000378:metabolism / Q000648:ultrastructure; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D046529:Microscopy, Electron, Transmission; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D008870:Microtubules / Q000378:metabolism* / Q000648:ultrastructure; D009474:Neurons / Q000378:metabolism* / Q000502:physiology / Q000648:ultrastructure; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D010641:Phenotype; D034622:RNA Interference; D051381:Rats
chemical_list: D003598:Cytoskeletal Proteins; D008869:Microtubule-Associated Proteins; C512806:NIN protein, human; C000619274:Nin protein, rat; D009687:Nuclear Proteins