The timing of when creatures in the animal kingdom eat plays a crucial role in their survival and overall well-being. This finely tuned behaviour is orchestrated by a combination of internal and external factors, including circadian rhythms, which act as the “master clock.” However, the specific mechanisms governing feeding behaviour in animals remain a puzzle. A recent study, led by Associate Professor Kanae Ando of Tokyo Metropolitan University, used fruit flies as a model organism to shed light on this intricate process.
ANIMALS EAT; CAFE ASSAY REVEALS INSIGHTS
To investigate how fruit flies regulate their eating patterns, the research team employed a CAFE assay. This method allowed them to precisely measure individual flies’ food consumption at different times. The study began by examining how flies align their eating habits with light cues.
In a light/dark cycle, previous research had already shown that flies tend to eat more during the daytime, even when mutations affected core circadian clock genes like period (per) and timeless (tim). Instead, the team turned their attention to the quasimodo (qsm) gene, responsible for a light-responsive protein that influences clock neurons’ activity. By interfering with qsm, they discovered a significant impact on the daytime feeding patterns, revealing that qsm plays a role in synchronizing feeding to a light-mediated rhythm.
However, this synchronization was not observed in flies feeding in constant darkness. For flies with mutations in their core circadian clock genes (per, tim, cyc, and clk), disruptions in their daily feeding patterns were severe. Notably, the loss of cyc and clk genes had a more pronounced effect, especially in creating bimodal feeding patterns that encompass both eating and fasting periods, particularly within metabolic tissues.
ANIMALS EAT; NERVE CELLS AND MOLECULAR CLOCK GENES
The study also delved into how these feeding patterns align with the daily cycle. Rather than metabolic tissues, molecular clock genes in nerve cells emerged as the primary regulators. These findings offer a glimpse into how various internal clocks in an organism coordinate feeding and fasting cycles and align them with diurnal rhythms.
Understanding the mechanisms behind feeding habits not only promises insights into animal behaviour but also holds the potential for novel treatments for eating disorders.
