Neuronal morphogenesis in Drosophila
The Rumpf lab uses Drosophila to study the processes that determine the morphology of axons and dendrites during development. Due to their well-established genetics and short life cycle (see schematic), flies are an ideal model organism in developmental biology. Our favourite model neurons are „class IV dendritic arborization“ (c4da) neurons, peripheral sensory neurons located in the skin of Drosophila larvae. Their axons and dendrites can be easily visualized by expression of fluorescent markers. The big picture above (by Sandra Rode & Svende Herzmann) is a whole-mount Drosophila larva expressing Green Fluorescent Protein (GFP) specifically in c4da neurons.
In collaboration with Jan Huisken, MPI Dresden.
Not only outgrowth of neuronal processes, but also regressive events are important for a neuron to reach its mature morphology during development. Retraction or degeneration of axons and dendrites without loss of the cell body are collectively referred to as „pruning“. C4da neurons specifically prune their larval dendrites at the onset of the pupal phase (see movie). C4da neuron dendrite pruning is induced by the steroid hormone ecdysone and involves the local degeneration of the larval dendrites. Dendrite pruning is a stunning example of spatial regulation: in the dendrites, the cytoskeleton is locally destroyed, and the plasma membrane is precisely cut at a predetermined break site. All the while, the cytoskeleton and membrane of the cell body and axon are maintained and remain untouched.