Receptor-type guanylate cyclase is required for carbon dioxide sensation by Caenorhabditis elegans

Proc Natl Acad Sci U S A. 2011 Jan 4;108(1):254-9. doi: 10.1073/pnas.1017354108. Epub 2010 Dec 20.


CO(2) is both a critical regulator of animal physiology and an important sensory cue for many animals for host detection, food location, and mate finding. The free-living soil nematode Caenorhabditis elegans shows CO(2) avoidance behavior, which requires a pair of ciliated sensory neurons, the BAG neurons. Using in vivo calcium imaging, we show that CO(2) specifically activates the BAG neurons and that the CO(2)-sensing function of BAG neurons requires TAX-2/TAX-4 cyclic nucleotide-gated ion channels and the receptor-type guanylate cyclase GCY-9. Our results delineate a molecular pathway for CO(2) sensing and suggest that activation of a receptor-type guanylate cyclase is an evolutionarily conserved mechanism by which animals detect environmental CO(2).

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Base Sequence
  • Biological Evolution
  • Caenorhabditis elegans / enzymology
  • Caenorhabditis elegans / physiology*
  • Caenorhabditis elegans Proteins / metabolism*
  • Carbon Dioxide / metabolism*
  • Carbon Dioxide / toxicity
  • Chemotaxis / drug effects
  • Chemotaxis / physiology*
  • Cluster Analysis
  • DNA Primers / genetics
  • Gene Components
  • Guanylate Cyclase / metabolism*
  • Ion Channels / metabolism*
  • Microscopy, Confocal
  • Molecular Sequence Data
  • Neurons / metabolism*
  • Phylogeny
  • Receptors, Guanylate Cyclase-Coupled / metabolism*
  • Sequence Analysis, DNA
  • Smell / genetics
  • Smell / physiology*
  • Transgenes / genetics


  • Caenorhabditis elegans Proteins
  • DNA Primers
  • Ion Channels
  • tax-2 protein, C elegans
  • tax-4 protein, C elegans
  • Carbon Dioxide
  • GCY-9 protein, C elegans
  • Guanylate Cyclase
  • Receptors, Guanylate Cyclase-Coupled

Associated data

  • GENBANK/HQ636455
  • GEO/GSE23769