Understanding Feeding Rhythms in Animals: Tokyo Metropolitan University Study
Introduction: Researchers at Tokyo Metropolitan University delved into the feeding rhythms of fruit flies to unravel the innate knowledge animals possess regarding meal times. This investigation aimed to shed light on how environmental factors influence punctual feeding routines.
The Role of Circadian Rhythm: Many animals feed at specific times each day, and this regularity is influenced by environmental cues like light, temperature, food availability, and potential threats. The circadian rhythm, a shared physiological cycle among diverse organisms, acts as a “master clock” guiding rhythmic behaviors.
Peripheral Clocks and External Cues: Animals also possess “peripheral clocks” with unique biochemical pathways that can adjust based on external cues, such as feeding. However, the direct connection between these peripheral clocks and feeding behaviors has remained largely elusive.
Model Organism: The study focused on fruit flies as a model organism, surprisingly sharing many characteristics with more complex animals, including humans. The researchers employed a meticulous method called CAFE assay to measure individual flies’ feeding amounts and understand their eating patterns in relation to light.
Unraveling Genetic Insights: Previous research indicated that even with mutations in core circadian genes (period and timeless), flies predominantly fed during the day. The researchers then turned their attention to the quasimodo (qsm) gene, discovering its crucial role in aligning feeding with light-based rhythms when its expression was reduced.
Constant Darkness Reveals Disruptions: In constant darkness, flies with mutations in core circadian genes exhibited erratic feeding behaviors. The combination of cycle (cyc) and clock (clk) genes proved crucial for establishing clear eating and fasting intervals, particularly in metabolic tissues. Molecular clock genes in nerve cells emerged as the primary drivers of these patterns in the absence of light.
Implications and Future Directions: The study’s findings offer an initial understanding of how different internal clocks within an organism influence feeding cycles and align with daily rhythms. These insights into feeding behaviors may pave the way for innovative treatments for eating disorders, given the coordination of feeding/fasting rhythms with metabolism, aging, and life span. Further studies in this realm hold promise for contributing to human health.