Starvation-Induced Elevation of Taste Responsiveness and Expression of a Sugar Taste Receptor Gene in Drosophila melanogaster

Abstract

Abstract: Animals increase their feeding motivation under starved conditions. Here the authors test if the starvation-induced increase of feeding motivation is different among wild-derived strains of Drosophila melanogaster. In behavioral experiments comparing the feeding behaviors of the strains Mel6 and TW1, only TW1 exhibited a decreased feeding threshold to sucrose following a 24-h starvation period. Starved TW1 preferably ingested a low concentration of sucrose. Starved TW1 also exhibited significant elevation of taste responsiveness to low concentrations of sucrose and enhanced expression of the Gr64a sucrose sugar receptor gene. TW1 survived longer than Mel6 when provided a less nutritious food (10 mM sucrose). Thus, the starvation-induced decrease in the behavioral and the sensory thresholds could be an advantage in searching for and utilizing less nutritious foods. These results show that the starvation-induced functional change in the taste sensory system is a possible strategy for survival during starvation or suboptimal nutrient periods.

Keywords::

• Drosophila
• feeding
• starvation
• sugar receptor
• survival
• taste response

ACKNOWLEDGMENTS

We thank Dr. Midori Sakura for her kind reading of our manuscript and giving helpful advice. This work was supported by Grants-in-Aid for Scientific Research (B) from the Ministry of Education, Culture, Sports, Science and Technology of Japan and by GCOE program, Kobe University, Japan.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.