A mechanosensory receptor required for food texture detection in Drosophila

Juan Antonio Sánchez-Alcañiz,Giovanna Zappia,Frédéric Marion-Poll,Richard Benton

doi:10.1038/ncomms14192

Abstract

Textural properties provide information on the ingestibility, digestibility and state of ripeness or decay of sources of nutrition. Compared with our understanding of the chemosensory assessment of food, little is known about the mechanisms of texture detection. Here we show that Drosophila melanogaster can discriminate food texture, avoiding substrates that are either too hard or too soft. Manipulations of food substrate properties and flies' chemosensory inputs indicate that texture preferences are revealed only in the presence of an appetitive stimulus, but are not because of changes in nutrient accessibility, suggesting that animals discriminate the substrates’ mechanical characteristics. We show that texture preference requires NOMPC, a TRP-family mechanosensory channel. NOMPC localizes to the sensory dendrites of neurons housed within gustatory sensilla, and is essential for their mechanosensory-evoked responses. Our results identify a sensory pathway for texture detection and reveal the behavioural integration of chemical and physical qualities of food.

Highlights

Textural properties provide information on the ingestibility, digestibility and state of ripeness or decay of sources of nutrition
Drosophila melanogaster provides an appealing model system to investigate the mechanisms of food texture assessment, as the feeding preferences of flies can be assessed through simple choice assays, and electrophysiological analyses[2] and powerful neurogenetic manipulations[3] can be used to ascribe sensory functions to specific receptors and neural pathways
We found that starved flies’ positional preference for 0.5% over 2% agarose was greatly diminished in the absence of sucrose (Fig. 2b, left and Supplementary Fig. 1b), which correlated with a substantial reduction in the percentage of flies feeding on these plates, as assessed by their ingestion of a food dye mixed in the agarose (Fig. 2b, right)

Summary

Introduction

Textural properties provide information on the ingestibility, digestibility and state of ripeness or decay of sources of nutrition. Manipulations of food substrate properties and flies’ chemosensory inputs indicate that texture preferences are revealed only in the presence of an appetitive stimulus, but are not because of changes in nutrient accessibility, suggesting that animals discriminate the substrates’ mechanical characteristics. Drosophila melanogaster provides an appealing model system to investigate the mechanisms of food texture assessment, as the feeding preferences of flies can be assessed through simple choice assays, and electrophysiological analyses[2] and powerful neurogenetic manipulations[3] can be used to ascribe sensory functions to specific receptors and neural pathways. We show that flies show robust and sensitive discrimination of food substrates of distinct textures, and identify a mechanosensory ion channel and neural population that are important for this sensory-guided feeding behaviour

Methods

Results

Conclusion