Abstract

Flies, like all animals, need to find suitable and safe food. Because the principal food source for Drosophila melanogaster is yeast growing on fermenting fruit, flies need to distinguish fruit with safe yeast from yeast covered with toxic microbes. We identify a functionally segregated olfactory circuit in flies that is activated exclusively by geosmin. This microbial odorant constitutes an ecologically relevant stimulus that alerts flies to the presence of harmful microbes. Geosmin activates only a single class of sensory neurons expressing the olfactory receptor Or56a. These neurons target the DA2 glomerulus and connect to projection neurons that respond exclusively to geosmin. Activation of DA2 is sufficient and necessary for aversion, overrides input from other olfactory pathways, and inhibits positive chemotaxis, oviposition, and feeding. The geosmin detection system is a conserved feature in the genus Drosophila that provides flies with a sensitive, specific means of identifying unsuitable feeding and breeding sites.

Published in

Cell
2012, Volume: 151, number: 6, pages: 1345-1357
Publisher: CELL PRESS

SLU Authors

• Becher, Paul

  • Department of Plant Protection Biology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Zoology


Publication identifier

DOI: https://doi.org/10.1016/j.cell.2012.09.046

Permanent link to this page (URI)

https://res.slu.se/id/publ/42859