Circadian Conflict: Engineering Unihemispheric Sleep in Rodent Models to Probe Mammalian Clock Flexibility

Yin et al. (2024) show that marine mammals have evolved molecular adaptations for unihemispheric slow-wave sleep, but the mechanisms remain mysterious—and are absent in standard lab animals. Using CRISPR/Cas9, we could introduce cetacean-specific mutations (like the F411Y mutation in NFIL3) into mice, and then use EEG and molecular profiling to see if this triggers partial unihemispheric sleep or altered circadian outputs. This experimental "evolutionary engineering" would test how flexible the mammalian circadian system really is, and whether clock genes can be locally regulated in different brain regions. The findings could revolutionize our understanding of sleep, resilience to circadian disruption, and even the evolution of brain function.

References:

1. Circadian Rhythm Mechanisms Underlying Convergent Adaptation of Unihemispheric Slow-Wave Sleep in Marine Mammals. Daiqing Yin, Zhenpeng Yu, Haojia Jiang, Yujie Chong, Cuijuan Zhong, Shixia Xu, Guang Yang (2024). Molecular biology and evolution.