Filopodia and actin arcs guide the assembly and transport of two populations of microtubules with unique dynamic parameters in neuronal growth cones.

ABSTRACT: We have used multimode fluorescent speckle microscopy (FSM) and correlative differential interference contrast imaging to investigate the actin-microtubule (MT) interactions and polymer dynamics known to play a fundamental role in growth cone guidance. We report that MTs explore the peripheral domain (P-domain), exhibiting classical properties of dynamic instability. MT extension occurs preferentially along filopodia, which function as MT polymerization guides. Filopodial bundles undergo retrograde flow and also transport MTs. Thus, distal MT position is determined by the rate of plus-end MT assembly minus the rate of retrograde F-actin flow. Short MT displacements independent of flow are sometimes observed. MTs loop, buckle, and break as they are transported into the T-zone by retrograde

SUBMITTER: Schaefer AW 

PROVIDER: S-EPMC2173029 | biostudies-literature | 2002 Jul

REPOSITORIES: biostudies-literature