Effects of salt taste disorder on behavior and lifespan in Drosophila melanogaster

Objectives: Taste disorders are relatively common, but it is unknown whether taste variations are related to ingestive behaviors and general health. We used genetic manipulation of functional chemosensory receptor neurons in the model organism Drosophila melanogaster (fruit fly) to determine how NaCI taste disorder leads to various changes in its behavior and lifespan. Materials and methods: Two types of flies with peripheral taste deficiency were prepared and analyzed: 1) Gr5a-rpr transgenic flies, which have partially defective receptor neurons that undergo apoptosis, and 2) Delta Xbs6 flies, a homeotic Pox neuro mutant that exhibits specific ablation of external taste organs, including most taste neurons, with other organs remaining intact. These flies were compared with wild type control flies (w(1118)) in terms of feeding and breeding (egg-laying) behaviors, both controlled by inputs from salt-sensitive taste neurons. Results: Control and Gr5a-rpr flies consumed NaCI in a dose-dependent manner, peaking at 80 mM. The Delta Xbs6 flies showed significantly decreased consumption in both sexes. NaCl-based selection of egg laying sites was almost absent in Delta Xbs6 females until the fourth day after emergence, with partial inhibition thereafter. However, there was no difference in lifespan between Delta Xbs6 and control flies. Conclusions: The results of this study suggest that although NaCI taste disorder results in reduced feeding and breeding behaviors in Drosophila, it does not impact lifespan. (C) 2018 Japanese Association for Oral Biology. Published by Elsevier B.V. All rights reserved.