Topic
CLOCK
About: CLOCK is a research topic. Over the lifetime, 4304 publications have been published within this topic receiving 242828 citations. The topic is also known as: KAT13D & bHLHe8.
Papers published on a yearly basis
Papers
TL;DR: Circadian rhythms are generated by one of the most ubiquitous and well-studied timing systems and are tamed by a master clock in the brain, which coordinates tissue-specific rhythms according to light input it receives from the outside world.
Abstract: Time in the biological sense is measured by cycles that range from milliseconds to years. Circadian rhythms, which measure time on a scale of 24 h, are generated by one of the most ubiquitous and well-studied timing systems. At the core of this timing mechanism is an intricate molecular mechanism that ticks away in many different tissues throughout the body. However, these independent rhythms are tamed by a master clock in the brain, which coordinates tissue-specific rhythms according to light input it receives from the outside world.
4,393 citations
TL;DR: Estimation of transcripts encoding selected hypothalamic peptides associated with energy balance was attenuated in the Clock mutant mice, suggesting that the circadian clock gene network plays an important role in mammalian energy balance.
Abstract: The CLOCK transcription factor is a key component of the molecular circadian clock within pacemaker neurons of the hypothalamic suprachiasmatic nucleus. We found that homozygous Clock mutant mice have a greatly attenuated diurnal feeding rhythm, are hyperphagic and obese, and develop a metabolic syndrome of hyperleptinemia, hyperlipidemia, hepatic steatosis, hyperglycemia, and hypoinsulinemia. Expression of transcripts encoding selected hypothalamic peptides associated with energy balance was attenuated in the Clock mutant mice. These results suggest that the circadian clock gene network plays an important role in mammalian energy balance.
2,499 citations
TL;DR: Genetic and genomic analysis suggests that a relatively small number of output genes are directly regulated by core oscillator components, and major processes regulated by the SCN and liver were found to be under circadian regulation.
2,426 citations
TL;DR: It is shown that temporal feeding restriction under light-dark or dark-dark conditions can change the phase of circadian gene expression in peripheral cell types by up to 12 h while leaving thephase of cyclic gene expressionIn the SCN unaffected.
Abstract: In mammals, circadian oscillators exist not only in the suprachiasmatic nucleus, which harbors the central pacemaker, but also in most peripheral tissues. It is believed that the SCN clock entrains the phase of peripheral clocks via chemical cues, such as rhythmically secreted hormones. Here we show that temporal feeding restriction under light–dark or dark–dark conditions can change the phase of circadian gene expression in peripheral cell types by up to 12 h while leaving the phase of cyclic gene expression in the SCN unaffected. Hence, changes in metabolism can lead to an uncoupling of peripheral oscillators from the central pacemaker. Sudden large changes in feeding time, similar to abrupt changes in the photoperiod, reset the phase of rhythmic gene expression gradually and are thus likely to act through a clock-dependent mechanism. Food-induced phase resetting proceeds faster in liver than in kidney, heart, or pancreas, but after 1 wk of daytime feeding, the phases of circadian gene expression are similar in all examined peripheral tissues.
2,354 citations
TL;DR: It is demonstrated that peripheral tissues express self-sustained, rather than damped, circadian oscillations and the existence of organ-specific synchronizers of circadian rhythms at the cell and tissue level is suggested.
Abstract: Mammalian circadian rhythms are regulated by the suprachiasmatic nucleus (SCN), and current dogma holds that the SCN is required for the expression of circadian rhythms in peripheral tissues. Using a PERIOD2::LUCIFERASE fusion protein as a real-time reporter of circadian dynamics in mice, we report that, contrary to previous work, peripheral tissues are capable of self-sustained circadian oscillations for >20 cycles in isolation. In addition, peripheral organs expressed tissue-specific differences in circadian period and phase. Surprisingly, lesions of the SCN in mPer2Luciferase knockin mice did not abolish circadian rhythms in peripheral tissues, but instead caused phase desynchrony among the tissues of individual animals and from animal to animal. These results demonstrate that peripheral tissues express self-sustained, rather than damped, circadian oscillations and suggest the existence of organ-specific synchronizers of circadian rhythms at the cell and tissue level.
2,334 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2025 | 49 |
| 2024 | 88 |
| 2023 | 179 |
| 2022 | 269 |
| 2021 | 262 |
| 2020 | 261 |