Circadian clocks in animals and plants arise from multiple and interconnected transcription–translation feedback loops that ensure the proper oscillation of thousands of genes in a tissue-specific manner. ‘The tick-tock of the molecular clock’ explains the transcription–translation feedback loop by describing the studies of circadian rhythms in Drosophila melanogaster, the fruit fly. The generation of a robust circadian rhythm entrained by the environment is achieved via multiple elements including the rate of transcription, translation, protein complex assembly, phosphorylation, other post-translation modification events, movement into the nucleus, transcriptional inhibition, and protein degradation. Similar mechanisms have been found in mammals, and insight is provided regarding research into how the mammalian molecular clock is entrained by light.
Inactivation of mRNA cap-binding protein complex in Drosophila melanogaster embryos under heat shock