A circadian clock gene homolog regulates developmental timing and male mating circuitry in C. elegans

Circadian rhythms and sleep are known regulators of neurodevelopment, yet the mechanisms by which they influence neuronal circuit formation remain unclear. In Caenorhabditis elegans, postembryonic development comprises four larval stages separated by developmentally timed sleep (DTS) and is regulated by homologs of circadian clock genes. Here, we leverage the well-defined male mating circuitry to investigate how developmental timing and sleep affect neurodevelopment. We found that males exhibit accelerated development with altered DTS patterns and reduced quiescence. Surprisingly, perturbing DTS does not impair male mating, suggesting that developmental sleep is not essential for functional circuit formation in this context. Disruption of the clock gene homolog ces-2 resulted in delayed and variable development in both sexes. In males, these timing defects were associated with reduced mating abilities and decreased synaptic connectivity within the mating circuitry. Together, our findings support the presence of conserved molecular machinery that coordinates developmental rhythms and provide insight into how such rhythms influence neurodevelopment.