Molecular and Cellular Organization of Taste Neurons in Adult Drosophila Pharynx

• Published in: Cell reports (Cambridge) 2017-12, Vol.21 (10), p.2978-2991
• Main Authors: Chen, Yu-Chieh David, Dahanukar, Anupama
• Format: Article
• Language: English
• Subjects: chemosensory receptors; Drosophila; feeding; gustatory receptors; ionotropic receptors; pharynx; taste
• ISSN: 2211-1247; 2211-1247
• DOI: 10.1016/j.celrep.2017.11.041

The Drosophila pharyngeal taste organs are poorly characterized despite their location at important sites for monitoring food quality. Functional analysis of pharyngeal neurons has been hindered by the paucity of molecular tools to manipulate them, as well as their relative inaccessibility for neurophysiological investigations. Here, we generate receptor-to-neuron maps of all three pharyngeal taste organs by performing a comprehensive chemoreceptor-GAL4/LexA expression analysis. The organization of pharyngeal neurons reveals similarities and distinctions in receptor repertoires and neuronal groupings compared to external taste neurons. We validate the mapping results by pinpointing a single pharyngeal neuron required for feeding avoidance of L-canavanine. Inducible activation of pharyngeal taste neurons reveals functional differences between external and internal taste neurons and functional subdivision within pharyngeal sweet neurons. Our results provide roadmaps of pharyngeal taste organs in an insect model system for probing the role of these understudied neurons in controlling feeding behaviors. [Display omitted] •Receptor-to-neuron maps of Drosophila adult pharyngeal taste organs•Functional tests of molecularly predicted L-canavanine-sensing neurons•Inducible activation survey of molecularly defined classes of internal taste neurons•Identification of differences between external and internal taste neurons Chen and Dahanukar carry out a large-scale, systematic analysis to understand the molecular organization of pharyngeal taste neurons. Taking advantage of the molecular genetic toolkit that arises from this map, they use genetic dissection strategies to probe the functional roles of selected pharyngeal neurons in food choice.