Ionotropic crustacean olfactory receptors

PLoS One. 2013;8(4):e60551. doi: 10.1371/journal.pone.0060551. Epub 2013 Apr 3.


The nature of the olfactory receptor in crustaceans, a major group of arthropods, has remained elusive. We report that spiny lobsters, Panulirus argus, express ionotropic receptors (IRs), the insect chemosensory variants of ionotropic glutamate receptors. Unlike insects IRs, which are expressed in a specific subset of olfactory cells, two lobster IR subunits are expressed in most, if not all, lobster olfactory receptor neurons (ORNs), as confirmed by antibody labeling and in situ hybridization. Ligand-specific ORN responses visualized by calcium imaging are consistent with a restricted expression pattern found for other potential subunits, suggesting that cell-specific expression of uncommon IR subunits determines the ligand sensitivity of individual cells. IRs are the only type of olfactory receptor that we have detected in spiny lobster olfactory tissue, suggesting that they likely mediate olfactory signaling. Given long-standing evidence for G protein-mediated signaling in activation of lobster ORNs, this finding raises the interesting specter that IRs act in concert with second messenger-mediated signaling.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Arthropod Proteins / chemistry
  • Arthropod Proteins / genetics
  • Arthropod Proteins / metabolism*
  • Dendrites / metabolism*
  • Gene Expression
  • Molecular Sequence Data
  • Olfactory Receptor Neurons / metabolism*
  • Olfactory Receptor Neurons / ultrastructure
  • Organ Specificity
  • Palinuridae / cytology
  • Palinuridae / physiology*
  • Protein Structure, Tertiary
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Receptors, Ionotropic Glutamate / chemistry
  • Receptors, Ionotropic Glutamate / genetics
  • Receptors, Ionotropic Glutamate / metabolism*
  • Sequence Homology, Amino Acid
  • Smell


  • Arthropod Proteins
  • RNA, Messenger
  • Receptors, Ionotropic Glutamate