Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

The molecular basis for water taste in Drosophila


The detection of water and the regulation of water intake are essential for animals to maintain proper osmotic homeostasis1. Drosophila and other insects have gustatory sensory neurons that mediate the recognition of external water sources2,3,4, but little is known about the underlying molecular mechanism for water taste detection. Here we identify a member of the degenerin/epithelial sodium channel family5, PPK28, as an osmosensitive ion channel that mediates the cellular and behavioural response to water. We use molecular, cellular, calcium imaging and electrophysiological approaches to show that ppk28 is expressed in water-sensing neurons, and that loss of ppk28 abolishes water sensitivity. Moreover, ectopic expression of ppk28 confers water sensitivity to bitter-sensing gustatory neurons in the fly and sensitivity to hypo-osmotic solutions when expressed in heterologous cells. These studies link an osmosensitive ion channel to water taste detection and drinking behaviour, providing the framework for examining the molecular basis for water detection in other animals.

Your institute does not have access to this article

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: ppk28-Gal4 labels neurons that respond to water.
Figure 2: The ppk28 gene is necessary for cellular and behavioural water responses.
Figure 3: Ectopic expression of ppk28 confers water sensitivity.
Figure 4: Heterologous cells expressing PPK28 respond to hypo-osmolarity.


  1. Bourque, C. W. Central mechanisms of osmosensation and systemic osmoregulation. Nature Rev. Neurosci. 9, 519–531 (2008)

    CAS  Article  Google Scholar 

  2. Evans, D. R. & Mellon, D. Electrophysiological studies of a water receptor associated with the taste sensilla of the blow-fly. J. Gen. Physiol. 45, 487–500 (1962)

    CAS  Article  Google Scholar 

  3. Meunier, N., Ferveur, J. F. & Marion-Poll, F. Sex-specific non-pheromonal taste receptors in Drosophila. Curr. Biol. 10, 1583–1586 (2000)

    CAS  Article  Google Scholar 

  4. Inoshita, T. & Tanimura, T. Cellular identification of water gustatory receptor neurons and their central projection pattern in Drosophila. Proc. Natl Acad. Sci. USA 103, 1094–1099 (2006)

    ADS  CAS  Article  Google Scholar 

  5. Kellenberger, S. & Schild, L. Epithelial sodium channel/degenerin family of ion channels: a variety of functions for a shared structure. Physiol. Rev. 82, 735–767 (2002)

    CAS  Article  Google Scholar 

  6. Awasaki, T. & Kimura, K. pox-neuro is required for development of chemosensory bristles in Drosophila. J. Neurobiol. 32, 707–721 (1997)

    CAS  Article  Google Scholar 

  7. Boll, W. & Noll, M. The Drosophila Pox neuro gene: control of male courtship behavior and fertility as revealed by a complete dissection of all enhancers. Development 129, 5667–5681 (2002)

    CAS  Article  Google Scholar 

  8. Yarmolinsky, D. A., Zuker, C. S. & Ryba, N. J. Common sense about taste: from mammals to insects. Cell 139, 234–244 (2009)

    CAS  Article  Google Scholar 

  9. Chyb, S., Dahanukar, A., Wickens, A. & Carlson, J. R. Drosophila Gr5a encodes a taste receptor tuned to trehalose. Proc. Natl Acad. Sci. USA 100 (suppl. 2). 14526–14530 (2003)

    ADS  CAS  Article  Google Scholar 

  10. Thorne, N., Chromey, C., Bray, S. & Amrein, H. Taste perception and coding in Drosophila. Curr. Biol. 14, 1065–1079 (2004)

    CAS  Article  Google Scholar 

  11. Wang, Z., Singhvi, A., Kong, P. & Scott, K. Taste representations in the Drosophila brain. Cell 117, 981–991 (2004)

    CAS  Article  Google Scholar 

  12. Marella, S. et al. Imaging taste responses in the fly brain reveals a functional map of taste category and behavior. Neuron 49, 285–295 (2006)

    CAS  Article  Google Scholar 

  13. Moon, S. J., Kottgen, M., Jiao, Y., Xu, H. & Montell, C. A taste receptor required for the caffeine response in vivo. Curr. Biol. 16, 1812–1817 (2006)

    CAS  Article  Google Scholar 

  14. Fischler, W., Kong, P., Marella, S. & Scott, K. The detection of carbonation by the Drosophila gustatory system. Nature 448, 1054–1057 (2007)

    ADS  CAS  Article  Google Scholar 

  15. Meunier, N., Marion-Poll, F. & Lucas, P. Water taste transduction pathway is calcium dependent in Drosophila. Chem. Senses 34, 441–449 (2009)

    CAS  Article  Google Scholar 

  16. Parks, A. L. et al. Systematic generation of high-resolution deletion coverage of the Drosophila melanogaster genome. Nature Genet. 36, 288–292 (2004)

    CAS  Article  Google Scholar 

  17. Hiroi, M., Meunier, N., Marion-Poll, F. & Tanimura, T. Two antagonistic gustatory receptor neurons responding to sweet-salty and bitter taste in Drosophila. J. Neurobiol. 61, 333–342 (2004)

    Article  Google Scholar 

  18. Liedtke, W. et al. Vanilloid receptor-related osmotically activated channel (VR-OAC), a candidate vertebrate osmoreceptor. Cell 103, 525–535 (2000)

    CAS  Article  Google Scholar 

  19. Werner-Reiss, U., Galun, R., Crnjar, R. & Liscia, A. Sensitivity of the mosquito Aedes aegypti (Culicidae) labral apical chemoreceptors to blood plasma components. J. Insect Physiol. 45, 485–491 (1999)

    CAS  Article  Google Scholar 

  20. Lindemann, B. Taste reception. Physiol. Rev. 76, 718–766 (1996)

    Article  Google Scholar 

  21. Gilbertson, T. A. Hypoosmotic stimuli activate a chloride conductance in rat taste cells. Chem. Senses 27, 383–394 (2002)

    CAS  Article  Google Scholar 

  22. Colbert, H. A., Smith, T. L. & Bargmann, C. I. OSM-9, a novel protein with structural similarity to channels, is required for olfaction, mechanosensation, and olfactory adaptation in Caenorhabditis elegans. J. Neurosci. 17, 8259–8269 (1997)

    CAS  Article  Google Scholar 

  23. Muraki, K. et al. TRPV2 is a component of osmotically sensitive cation channels in murine aortic myocytes. Circ. Res. 93, 829–838 (2003)

    CAS  Article  Google Scholar 

  24. Liu, L. et al. Drosophila hygrosensation requires the TRP channels water witch and nanchung. Nature 450, 294–298 (2007)

    ADS  CAS  Article  Google Scholar 

  25. Hummel, T., Krukkert, K., Roos, J., Davis, G. & Klambt, C. Drosophila Futsch/22C10 is a MAP1B-like protein required for dendritic and axonal development. Neuron 26, 357–370 (2000)

    CAS  Article  Google Scholar 

  26. Hiroi, M., Marion-Poll, F. & Tanimura, T. Differentiated response to sugars among labellar chemosensilla in Drosophila. Zoolog. Sci. 19, 1009–1018 (2002)

    Article  Google Scholar 

  27. Liu, L., Johnson, W. A. & Welsh, M. J. Drosophila DEG/ENaC pickpocket genes are expressed in the tracheal system, where they may be involved in liquid clearance. Proc. Natl Acad. Sci. USA 100, 2128–2133 (2003)

    ADS  CAS  Article  Google Scholar 

Download references


We thank K. Vranizan for assistance with microarray analyses. K. Gerhold and D. Bautista provided the TRPV4 construct, protocols and advice for HEK293 experiments; the Roelink laboratory provided tissue culture facilities and advice. G. Agarwaal generated heat map images in Matlab for data presentation. W. Fischler generated the NP1017 G-CaMP data in Supplementary Information. We are grateful to C. Zuker and members of the Scott laboratory for comments on the manuscript. This work was supported by a grant from the NIH (NIDCD), a Burroughs-Wellcome CAREER Award and a John Merck Award to K.S. and a NIH predoctoral fellowship to P.C. K.S. is an HHMI Early Career Scientist.

Author information

Authors and Affiliations



P.C. performed most experiments and co-wrote the manuscript. M.H. performed the electrophysiological recordings and the HEK293 heterologous experiments. J.N. provided expertise on the microarray experiments. K.S. co-wrote the manuscript and supervised the project.

Corresponding author

Correspondence to Kristin Scott.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

This file contains Supplementary Figures S1-S6 with legends and Supplementary Table S1. (PDF 8415 kb)

PowerPoint slides

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Cameron, P., Hiroi, M., Ngai, J. et al. The molecular basis for water taste in Drosophila. Nature 465, 91–95 (2010).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing