Major
Neuroscience
Anticipated Graduation Year
2023
Access Type
Open Access
Abstract
Circadian rhythms are approximately 24-hour cycles that occur in many essential biological processes, including feeding, body temperature, sleep, and hormone release. These are driven by an internal clock system that allows animals to coordinate behavioral and physiological processes with each other and to synchronize these processes to external environmental cycles. In the brain of Drosophila melanogaster, ~150 circadian clock neurons generate behavioral rhythms. Molecular clocks in clock neurons are synchronized to external environmental signals such as light through input pathways. In turn, output pathways receive and translate circadian signals from clock neurons to produce biological rhythms. However, there exists a gap in knowledge as to how neuronal pathways within the internal clock system control clock outputs. We recently identified the pars intercerebralis (PI) as an important circadian output center in flies, and furthermore showed that a subset of PI cells that express the neuropeptide SIFamide (SIFa) contributes to circadian rhythms of feeding. Here, we demonstrate a role for SIFa Receptor (SIFaR) in generating feeding rhythms. We find that constitutive loss of SIFaR results in developmental lethality. To circumvent this, we developed a conditional strategy that allows for adult-specific RNAi-mediate knockdown of SIFaR, and found that this produces a progressive degradation of circadian feeding rhythms. In future experiments we will use cell-selective RNAi knockdown to identify specific populations of neurons in which SIFaR must be expressed for flies to exhibit normal feeding rhythms. These studies will further delineate the circadian output pathways through which the circadian system modulates feeding behavior.
Faculty Mentors & Instructors
Dr. Cavanaugh
Supported By
Cura Scholars Program, Mulcahy Fellowship
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 License.
A Role for SIFa Receptor in the Regulation of Drosophila Circadian Feeding Rhythms
Circadian rhythms are approximately 24-hour cycles that occur in many essential biological processes, including feeding, body temperature, sleep, and hormone release. These are driven by an internal clock system that allows animals to coordinate behavioral and physiological processes with each other and to synchronize these processes to external environmental cycles. In the brain of Drosophila melanogaster, ~150 circadian clock neurons generate behavioral rhythms. Molecular clocks in clock neurons are synchronized to external environmental signals such as light through input pathways. In turn, output pathways receive and translate circadian signals from clock neurons to produce biological rhythms. However, there exists a gap in knowledge as to how neuronal pathways within the internal clock system control clock outputs. We recently identified the pars intercerebralis (PI) as an important circadian output center in flies, and furthermore showed that a subset of PI cells that express the neuropeptide SIFamide (SIFa) contributes to circadian rhythms of feeding. Here, we demonstrate a role for SIFa Receptor (SIFaR) in generating feeding rhythms. We find that constitutive loss of SIFaR results in developmental lethality. To circumvent this, we developed a conditional strategy that allows for adult-specific RNAi-mediate knockdown of SIFaR, and found that this produces a progressive degradation of circadian feeding rhythms. In future experiments we will use cell-selective RNAi knockdown to identify specific populations of neurons in which SIFaR must be expressed for flies to exhibit normal feeding rhythms. These studies will further delineate the circadian output pathways through which the circadian system modulates feeding behavior.