Synaptogenesis in Drosophila: coupling genetics and electrophysiology

Drosophila is one of the most fully described eukaryotic organisms and, as a system, offers the most advanced genetic and molecular techniques. In particular, Drosophila embryonic development has been subject to intensive genetic and molecular examination. Drosophila is also one of the few genetically malleable organisms to permit electrophysiological investigation and so allow detailed physiological characterization of specific molecular lesions. These two fields, the developmental and electrophysiological, are being coupled for the first time to examine a key aspect of neural development, synaptogenesis. Here, I describe synaptogenesis in the Drosophila embryo at the identified neuromuscular junction. I focus particular attention on the use of known genetic mutations to dissect the mechanisms of synapse formation. This simple, well-characterized synapse is already proving valuable in describing the defects of mutations in genes essential for synaptic development and function. In the long term, this system will allow us to systematically mutate the Drosophila genome to identify and describe the genetic and molecular pathways directing the construction of a synapse.