Imaging Microtubule Dynamics In Vivo in Drosophila Sensory Dendrites

Drosophila larval class IV sensory neurons are located just beneath the cuticle and are characterized by highly branched dendritic arbors that expand isotropically in two dimensions as the larvae develop. The growth of these arbors is driven by stochastic processes involving growth, shrinkage, and pausing of the dendritic terminal tips. To test the hypothesis that tip dynamics are driven by microtubule dynamics, protocols have been developed for imaging fluorescently labeled microtubules within dendrites. The method enables visualization of microtubule dynamics in fine terminal dendrites of class IV sensory neurons using confocal microscopy. It is designed to preserve dendritic arbor morphology during imaging while allowing microtubules to be visualized together with a membrane marker. This manuscript describes the procedures used to prepare Drosophila larvae for live imaging and to visualize fluorescently labeled microtubules in dendrites. The protocol, therefore, provides an approach to examining microtubule behavior in fine terminal dendrites while remaining compatible with membrane co-labeling.