Rhythmic activity of timeless helps regulate daily cycles in period gene control

The clock gene timeless (tim) is required for circadian rhythmicity in Drosophila.

• tim RNA levels follow a circadian rhythm.
• The rhythm of tim RNA accumulation matches the previously reported phase and period of per.
• tim RNA oscillations depend on the presence of PER and TIM proteins.
• The cyclic expression of tim may control the timing of PER protein accumulation and its movement into the nucleus.
• tim could promote circadian rhythms of per and tim transcription by timing their RNA and protein accumulation.

Simplified