Ionotropic Chemosensory Receptors Mediate the Taste and Smell of Polyamines

PLoS Biol. 2016 May 4;14(5):e1002454. doi: 10.1371/journal.pbio.1002454. eCollection 2016 May.


The ability to find and consume nutrient-rich diets for successful reproduction and survival is fundamental to animal life. Among the nutrients important for all animals are polyamines, a class of pungent smelling compounds required in numerous cellular and organismic processes. Polyamine deficiency or excess has detrimental effects on health, cognitive function, reproduction, and lifespan. Here, we show that a diet high in polyamine is beneficial and increases reproductive success of flies, and we unravel the sensory mechanisms that attract Drosophila to polyamine-rich food and egg-laying substrates. Using a combination of behavioral genetics and in vivo calcium imaging, we demonstrate that Drosophila uses multisensory detection to find and evaluate polyamines present in overripe and fermenting fruit, their favored feeding and egg-laying substrate. In the olfactory system, two coexpressed ionotropic receptors (IRs), IR76b and IR41a, mediate the long-range attraction to the odor. In the gustatory system, multimodal taste sensation by IR76b receptor and GR66a bitter receptor neurons is used to evaluate quality and valence of the polyamine providing a mechanism for the fly's high attraction to polyamine-rich and sweet decaying fruit. Given their universal and highly conserved biological roles, we propose that the ability to evaluate food for polyamine content may impact health and reproductive success also of other animals including humans.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aedes / physiology
  • Animal Feed
  • Animals
  • Animals, Genetically Modified
  • Chemoreceptor Cells / physiology
  • Drosophila Proteins / genetics
  • Drosophila Proteins / metabolism*
  • Drosophila Proteins / physiology
  • Drosophila melanogaster / physiology*
  • Feeding Behavior / physiology*
  • Female
  • Male
  • Musa / chemistry
  • Mutation
  • Oviposition
  • Polyamines*
  • Receptors, Cell Surface / genetics
  • Receptors, Cell Surface / metabolism*
  • Receptors, Ionotropic Glutamate / genetics
  • Receptors, Ionotropic Glutamate / metabolism*
  • Reproduction
  • Smell / physiology
  • Sodium Channels / genetics
  • Sodium Channels / metabolism*


  • Drosophila Proteins
  • Gr66a protein, Drosophila
  • IR41a protein, Drosophila
  • IR76b protein, Drosophila
  • Polyamines
  • Receptors, Cell Surface
  • Receptors, Ionotropic Glutamate
  • Sodium Channels

Grant support

This study was generously supported by the German Research Foundation, CRC870/A05 to ICGK (, an Boehringer Ingelheim Exploration Grant to ICGK (, the Max Planck Society to ICGK (, the Linnaeus Initiative ‘Insect Chemical Ecology, Ethology and Evolution’ IC-E3 to RK, and an EMBO Young Investigator award to ICGK ( The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.