Int. J. Dev. Biol. 51: 679 - 687 (2007)
Special Issue: Ear Development
Development of Johnston's organ in Drosophila
Published: 1 September 2007
Abstract
Practically the entire progress in genetic and molecular elucidation of hearing mechanisms in the fruitfly, Drosophila melanogaster has occurred in the last decade. The Johnston's organ (JO), located in the fly's antenna, formally has been confirmed as the major auditory organ and mutations in many genes required for hearing have been identified using a variety of approaches. These include mutagenesis screens, gene expression patterns and other candidate gene approaches including homology to known human hereditary hearing loss genesalmost all of which have been identified over the same time period. Thus, Drosophila hearing research has metamorphosed into an exciting research field that ties together intricate physiological and mechanical mechanisms with complex developmental biology. Several reviews have summarized aspects of this progress (Eberl, 1999, Caldwell and Eberl, 2002, Jarman, 2002, Robert and Göpfert, 2002, Todi et al., 2004, Boekhoff-Falk, 2005). In this paper, we first focus on advances that reinforce the emerging conclusion that the JO is much more than a mere recapitulation of the canonical larval chordotonal sense organ type. Instead, the Drosophila JO represents an evolution to a highly specialized organ for hearing, clearly chordotonal in nature, but with some features as different from ancestral proprioceptors as the butterfly is from the caterpillar. Second, we highlight some important questions raised by these considerations, the answers to which will represent significant advances in the decade(s) to come.
Keywords
audition, hearing, scolopidia, chordotonal organ, active mechanics