Internal and body clocks controlling daily rhythms in fruit flies

CLOCK (CLK) and CYCLE (CYC) activate per and tim transcription while simultaneously repressing Clk through vrille (vri).

• CLK-CYC binding to E-box elements leads to the activation of per and tim, which are essential for circadian rhythms.
• Vri acts as a negative regulator in the Clk feedback loop, explaining the alternating phases of Clk and its target genes.
• CRYPTOCHROME (CRY) has a light-independent role in the oscillator that influences olfaction rhythms, similar to its function in mammals.
• Olfaction rhythms depend on peripheral oscillators that differ from the central lateral neuron (LN) oscillators responsible for locomotor activity.
• Preliminary findings indicate that antennal oscillator cells alone can drive olfaction rhythms, while central oscillators have minimal influence in this context.

Simplified