Axon and dendrite pruning in Drosophila

•Neuronal pruning is a widespread strategy crucial for refining the nervous systems.•MB γ and ddaC neurons are two attractive models for studying neurite pruning.•Neurite pruning involves the communication between neurons and neighboring cells.•Axon and dendrite pruning requires activation and transduction of ecdysone pathway.•Axon and dendrite pruning requires conserved and differential mechanisms.

Pruning, a process by which neurons selectively remove exuberant or unnecessary processes without causing cell death, is crucial for the establishment of mature neural circuits during animal development. Yet relatively little is known about molecular and cellular mechanisms that govern neuronal pruning. Holometabolous insects, such as Drosophila, undergo complete metamorphosis and their larval nervous systems are replaced with adult-specific ones, thus providing attractive models for studying neuronal pruning. Drosophila mushroom body and dendritic arborization neurons have been utilized as two appealing systems to elucidate the underlying mechanisms of axon and dendrite pruning, respectively. In this review we highlight recent developments and discuss some similarities and differences in the mechanisms that regulate these two distinct modes of neuronal pruning in Drosophila.