The Circadian Clock Interacts with Metabolic Physiology to Influence Reproductive Fitness

SummaryCircadian rhythms are regulated by a synchronized system of central and peripheral clocks. Here, we show that a clock in the Drosophila fat body drives rhythmic expression of genes involved in metabolism, detoxification, the immune response, and steroid hormone regulation. Some of these genes cycle even when the fat body clock is disrupted, indicating that they are regulated by exogenous factors. Food is an important stimulus, as limiting food availability to a 6 hr interval each day drives rhythmic expression of genes in the fat body. Restricting food to a time of day when consumption is typically low desynchronizes internal rhythms because it alters the phase of rhythmic gene expression in the fat body without affecting the brain clock. Flies maintained on this paradigm produce fewer eggs than those restricted to food at the normal time. These data suggest that desynchrony of endogenous rhythms, caused by aberrant feeding patterns, affects reproductive fitness.

► Drosophila fat body clock controls rhythmic expression of many genes ► Restricted feeding can drive rhythmic gene expression in fat body, not brain ► Restricted feeding drives rhythmic gene expression in fat bodies of clockless flies ► Mistimed feeding desynchronizes rhythms across tissues