Defense Date


Document Type


Degree Name

Master of Science



First Advisor

Young-Jai You


Appetite control and satiety mechanisms help animals maintain energy homeostasis; however, these mechanisms can be misregulated, leading to overweight and obesity. Caenorhabditis elegans is an excellent model system to study appetite and satiety because of its conserved behavioral aspects of satiety and conserved molecular mechanisms. ASI senses nutrition and its activity is required for the behavioral state of satiety quiescence. The purpose of this thesis project was to elucidate the function of cGMP signaling in ASI by looking at behavioral effects from the pharmacological use of sildenafil (Viagra), a PDE inhibitor, and the effects on ASI activation from mutating guanylyl cyclase DAF-11. Sildenafil treatment increases satiety quiescence and decreases fat storage in a PDE-dependent manner. The daf-11 mutation decreased overall fluorescence intensity of ASI activation and the frequency at which ASI activated by about 50% compared to wild-type worms, suggesting that DAF-11 plays an important role in ASI to promote satiety.


© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission


Available for download on Monday, May 04, 2020