Wild-Derived House Mice (Mus musculus) Are Able to Cope With a Constant Light Environment

Area of Science:

• Chronobiology
• Mitochondrial biology
• Metabolic health

Background:

• Altered nighttime lighting disrupts circadian rhythms, impacting feeding, sleep, and metabolism.
• This disruption increases the risk of cardiometabolic diseases, but underlying mechanisms are unclear.
• Mitochondrial function is crucial for metabolic performance and may reveal physiological costs of light at night.

Purpose of the Study:

• To investigate the physiological effects of altered light environments on wild-derived mice.
• To examine changes in bioenergetic capacity, body condition, and oxidative damage.
• To assess mitochondrial responses in liver and skeletal muscle.

Main Methods:

• 36 wild-derived house mice (Mus musculus) were exposed to continuous light, darkness, or a control light cycle for 6 weeks.
• Whole-organism and subcellular bioenergetic capacity were measured.
• Body condition and oxidative damage markers were assessed.

Main Results:

• Six weeks of constant light or darkness caused negligible changes in bioenergetic capacity, body condition, and oxidative damage.
• No significant mitochondrial responses were observed in the liver or skeletal muscle of either sex.
• No differences in mitochondrial volume or lipid peroxidation in the liver were detected.

Conclusions:

• Wild-derived mice demonstrated resilience to altered light environments.
• Mice were able to circumvent challenges posed by constant light or darkness without apparent physiological consequences.
• Mitochondrial function and metabolic health were not significantly impacted by the tested light conditions.