Molecular and cellular basis of sodium sensing in Drosophila labellum

• Published in: iScience 2024-07, Vol.27 (7), p.110248, Article 110248
• Main Authors: Asefa, Wayessa Rahel, Woo, Jin-Nyeong, Kim, Seon Yeong, Choi, Hyungjun, Sung, Hayeon, Choi, Min Sung, Choi, Minkook, Yoon, Sung-Eun, Kim, Young-Joon, Suh, Byung-Chang, Kang, KyeongJin, Kwon, Jae Young
• Format: Article
• Language: English
• Subjects: Biological sciences; Natural sciences; Neuroscience
• ISSN: 2589-0042; 2589-0042
• DOI: 10.1016/j.isci.2024.110248

Appropriate ingestion of salt is essential for physiological processes such as ionic homeostasis and neuronal activity. Generally, low concentrations of salt elicit attraction, while high concentrations elicit aversive responses. Here, we observed that sugar neurons in the L sensilla of the Drosophila labellum cf. responses to NaCl, while sugar neurons in the S-c sensilla do not respond to NaCl, suggesting that gustatory receptor neurons involved in NaCl sensing may employ diverse molecular mechanisms. Through an RNAi screen of the entire Ir and ppk gene families and molecular genetic approaches, we identified IR76b, IR25a, and IR56b as necessary components for NaCl sensing in the Drosophila labellum. Co-expression of these three IRs in heterologous systems such as S2 cells or Xenopus oocytes resulted in a current in response to sodium stimulation, suggesting formation of a sodium-sensing complex. Our results should provide insights for research on the diverse combinations constituting salt receptor complexes. [Display omitted] •Sugar neurons in L sensilla cf. responses to NaCl, but not those in S-c sensilla•Ir56b mutant shows impaired physiological responses to NaCl in the Drosophila labellum•IR56b is involved in attraction behavior induced by low concentrations of NaCl•IR76b, IR25a, and IR56b can form a complex that responds to NaCl in heterologous systems Natural sciences; Biological sciences; Neuroscience