Biology subjects

Iiams, S. E.

Publications and source records attributed to Iiams, S. E..

2 recordsLinked to original sources

bioRxiv2025

Time-Restricted Feeding Extends Healthspan in Female and Lifespan in Male C57BL/6J Mice

Time-restricted feeding (TRF) aligned with an organisms circadian rhythm has been shown to improve health, but its long-term effects on healthspan and lifespan in mammals, especially under normal dietary conditions, remain unclear. Here, we examined the impact of 12-hour (h) and 8h nightly TRF windows in male and female mice fed regular chow. TRF improved multiple health measures, including behavioral rhythmicity, body weight and composition, frailty, and disease onset. These effects were most pronounced in the 8h-TRF group, which exhibited voluntary caloric restriction in addition to time restriction. A composite Healthspan Index revealed that TRF extended healthspan in both sexes, though the benefits were more prolonged in females relative to their total lifespan. Median lifespan was significantly extended in males under 8h-TRF by 12%, whereas females showed no significant lifespan extension, highlighting sex-specific responses to TRF.

physiology↗

bioRxiv2023

Monarch butterfly Cryptochrome 1 loss-of-function mutants reveal differences in light entrainment of 24-hour behavioral rhythms in insects

Light is one of the strongest cues for entrainment of circadian clocks in most organisms. Previous work in Drosophila melanogaster (dm) has shown that entrainment relies on both the visual system and the circadian, blue-light photoreceptor Cryptochrome (dmCRY). Here, we used the monarch butterfly Danaus plexippus (dp) to test conservation of this mechanism among insects and the relative importance of monarch Cryptochrome 1 (dpCry1) in the entrainment of its clock in vivo. We showed that loss of functional dpCry1 abolishes adult circadian eclosion behavior and molecular circadian rhythms in the monarch brain. These rhythms can be restored by entrainment to temperature cycles, demonstrating that the core circadian clock is intact in dpCry1 mutants. Importantly, we showed that rhythmic flight activity is also disrupted in dpCry1 mutants but not in the visually impaired dpNinaB1 mutants, suggesting that unlike Drosophila light-entrainment of the monarch circadian clock relies solely on dpCRY1 photoreception.

neuroscience↗