Axonal targeting of olfactory receptor neurons in Drosophila is controlled by Dscam

Neuron. 2003 Jan 23;37(2):221-31. doi: 10.1016/s0896-6273(02)01183-2.


Different classes of olfactory receptor neurons (ORNs) in Drosophila innervate distinct targets, or glomeruli, in the antennal lobe of the brain. Here we demonstrate that specific ORN classes require the cell surface protein Dscam (Down Syndrome Cell Adhesion Molecule) to synapse in the correct glomeruli. Dscam mutant ORNs frequently terminated in ectopic sites both within and outside the antennal lobe. The morphology of Dscam mutant axon terminals in either ectopic or cognate targets was abnormal. Target specificity for other ORNs was not altered in Dscam mutants, suggesting that different ORNs use different strategies to regulate wiring. Multiple forms of Dscam RNA were detected in the developing antenna, and Dscam protein was localized to developing ORN axons. We propose a role for Dscam protein diversity in regulating ORN target specificity.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Alleles
  • Animals
  • Axons / physiology*
  • Cell Adhesion Molecules
  • Drosophila / physiology*
  • Drosophila Proteins*
  • Immunohistochemistry
  • In Situ Hybridization
  • Isomerism
  • Mutation / physiology
  • Neuropil / physiology
  • Olfactory Receptor Neurons / metabolism
  • Olfactory Receptor Neurons / physiology*
  • Phenotype
  • Presynaptic Terminals / physiology
  • Proteins / genetics
  • Proteins / physiology*
  • Pupa / physiology
  • RNA, Messenger / biosynthesis
  • Reverse Transcriptase Polymerase Chain Reaction
  • Sense Organs / growth & development
  • Sense Organs / physiology
  • Synapses / physiology


  • Cell Adhesion Molecules
  • Drosophila Proteins
  • Dscam1 protein, Drosophila
  • Proteins
  • RNA, Messenger