Old cogs, new clocks: a conserved protein complex controls developmental and circadian timing

The circadian clock protein Period and its C. elegans counterpart LIN-42, involved in regulation of daily rhythms and developmental timing, respectively, have long been suspected to function mechanistically in a similar manner. The new study by Spangler et al, (2025) in The EMBO Journal reveals that LIN-42 forms a functional complex with the CkIδ/ε kinase homologue KIN-20, establishing the first conserved timing module shared between circadian and developmental timing programs.