Participates in a novel circadian output pathway that conveys temporal and food status information to feeding-relevant metabolisms and activities. Involved in male courtship behavior. In the brain-associated fat body, transcription is enhanced by the dsx and fru male-specific isoforms and repressed by the dsx female-specific isoform. Expression is largely restricted to head, with limited expression detectable in cardia and crop. In entrained individuals, expression is observed in the brain cortex (region between optic lobe and central complex), photoreceptors and antennae. In asynchronous individuals, expression is seen in third antennal segment and male-specific expression is seen in the brain-associated fat body. Starvation and circadian clock. In the heads of entrained flies, levels fluctuate daily and the cycle phase is delayed with respect to per and tim. Cycling appears to be linked to the endogenous clock rather than light stimuli. Belongs to the TO family.