Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul, Republic of Korea
Subash Dhakal
Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul, Republic of Korea
Bhanu Shrestha
Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul, Republic of Korea
Dharmendra Kumar Nath
Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul, Republic of Korea
Yunjung Kim
Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul, Republic of Korea
Anindya Ganguly
Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, United States
Neuroscience Research Institute and Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, Santa Barbara, United States
Salt (NaCl), is an essential nutrient for survival, while excessive salt can be detrimental. In the fruit fly, Drosophila melanogaster, internal taste organs in the pharynx are critical gatekeepers impacting the decision to accept or reject a food. Currently, our understanding of the mechanism through which pharyngeal gustatory receptor neurons (GRNs) sense high salt are rudimentary. Here, we found that a member of the ionotropic receptor family, Ir60b, is expressed exclusively in a pair of GRNs activated by high salt. Using a two-way choice assay (DrosoX) to measure ingestion volume, we demonstrate that IR60b and two co-receptors IR25a and IR76b are required to prevent high salt consumption. Mutants lacking external taste organs but retaining the internal taste organs in the pharynx exhibit much higher salt avoidance than flies with all taste organs but missing the three IRs. Our findings highlight the vital role for IRs in a pharyngeal GRN to control ingestion of high salt.
