Summary
This thesis-level study characterizes how Period (Per1, Per2) and Dec (Dec1, Dec2) genes interact within the SCN circadian pacemaker, revealing synergistic and antagonistic relationships that affect locomotor rhythms, entrainment, and clock gene expression. For lighting designers and chronobiologists, these findings clarify the molecular pathways through which light exposure resets the clock, particularly implicating Per2 as essential for photic phase delay responses.
Key Findings
- Per1/Dec double and triple mutant mice showed advanced activity onset under light-dark cycles, indicative of impaired sleep behavior and synergistic Per1-Dec interactions in photic entrainment.
- Under free-running conditions, Per1-Dec interactions remained synergistic while Per2-Dec interactions became antagonistic, with partial rescue of the Per2 phenotype including period length and rhythmicity.
- Dec genes together with PER1 were shown for the first time to activate Bmal1 transcription in the SCN, revealing a bimodular regulatory function that is time-of-day dependent.
- Photic phase delay resetting was found to require Per2/PER2 as essential, with only a minor role for Per1/PER1, providing a molecular model for how light resets the circadian clock.
Categories
Sleep & Circadian Health: Investigates genetic interactions between Per and Dec clock genes in the mammalian circadian pacemaker, with implications for entrainment, period length, and sleep behavior.
The Science of Light: Examines photic entrainment and phase delay resetting mechanisms at the molecular level, identifying roles of Per1/Per2 and Dec genes in light-driven clock synchronization.
Author(s)
B Bode
Publication Year
2011
Related Publications
Sleep & Circadian Health
- Phototransduction by retinal ganglion cells that set the circadian clock
- The mammalian circadian timing system: organization and coordination of central and peripheral clocks
- The twoāprocess model of sleep regulation: a reappraisal
- Melanopsin is required for non-image-forming photic responses in blind mice
- Strange vision: ganglion cells as circadian photoreceptors
The Science of Light
- Phototransduction by retinal ganglion cells that set the circadian clock
- Color appearance models
- The mammalian circadian timing system: organization and coordination of central and peripheral clocks
- Diminished pupillary light reflex at high irradiances in melanopsin-knockout mice
- Melanopsin is required for non-image-forming photic responses in blind mice