Studies of mechanosensation using the fly

Mechanosensation requires the transduction of mechanical stimuli into neuronal impulses. It encompasses not only the sense of touch but also proprioception and hearing. In contrast to sight, smell and taste, relatively little is known about the molecular machinery of mechanosensation. It is already clear, however, that important aspects are conserved across phyla, from Caenorhabditis elegans to humans. Drosophila melanogaster is well placed to make a significant contribution to this field. Its advantages include a sequenced genome allied with powerful genetic techniques, and the ability to conduct electrophysiological recording from mechanoreceptor neurons. For human geneticists, it is expected that Drosophila studies will provide a source of candidate genes whose human homologues can be examined for roles in mechanosensory development, function and disease. ANATOMY OF MECHANOSENSATION As an arthropod, Drosophila has a tough, mechanically resistant exoskeleton, which is not conducive to sensation of touch, and so this modality is largely detected via a battery of specialised mechanoreceptive sense organs inserted in the cuticle (external sense organs) (1). These are most noticeable a