Chronobiology of the intestinal tract of the mouse

Scheving, Lawrence E.; Tsai, T H

doi:10.1002/aja.1001680405

Cited by 82 publications

(32 citation statements)

References 73 publications

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“…The higher FE caused by feeding in the morning may be attributed to low-maintenance requirements, efficient nutrient accumulation or an alteration in body composition. Circadian rhythms of cell proliferation, intestinal enzymes, monosaccharide transport, and the height and width of villi in the intestinal tract are entrained (or synchronized) to the feeding schedule; however, numerous enzyme rhythms persist in fasting animals (Scheving et al, 1983). Pigs that were fed identical meals at 12-h intervals showed higher amino-acid utilization and lower plasma urea response in the morning than in the evening (Koopmans et al, 2006).…”

Section: Discussionmentioning

confidence: 99%

The effects of feeding time and time-restricted feeding on the fattening traits of White Roman geese

Chen

et al. 2014

Animal

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This study comprises two trials that investigated the effects of feeding time and time-restricted feeding on the fattening traits and plasma metabolite levels of White Roman geese. In Trial I, 24 geese aged 8 weeks of each sex were allowed free access to a fattening diet for 1 h either in the morning (morning-feeding group) or afternoon (afternoon-feeding group). At 12 weeks of age, blood samples were collected hourly for 4 h, beginning 1 h after feeding to determine the plasma levels of glucose, triacylglycerols and uric acid. The results showed a lower ( P < 0.05) daily feed intake (DFI) and daily gain (DG) and higher ( P < 0.05) feed efficiency (FE) for the morning-feeding group compared with those of the afternoon-feeding group. In addition, the postprandial plasma levels of glucose, triacylglycerols and uric acid did not differ ( P > 0.05) between groups. In Trial II, 12 geese aged 8 weeks of each sex were randomly assigned to either the ad libitum feeding group (control group) or time-restricted feeding group (restricted group). The geese in the control group were fed a fattening diet ad libitum, whereas those in the restricted group were allowed access to the diet for 2 h every morning. All geese were killed at 13 weeks of age and their carcass traits were evaluated. The results showed a lower DFI and DG and higher FE for the restricted group compared with those of the control group ( P < 0.05). In addition, the restricted group exhibited lower visceral and abdominal fat and higher empty digestive tract and liver weights than those of the control group (P < 0.05). The results showed that time-restricted feeding in the morning resulted in superior DG and FE compared with feeding in the afternoon. Moreover, time-restricted feeding implemented in the morning during the fattening period reduced DFI and increased FE in geese compared with ad libitum feeding.

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Section: Discussionmentioning

confidence: 99%

The effects of feeding time and time-restricted feeding on the fattening traits of White Roman geese

Chen

et al. 2014

Animal

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“…Previous studies have shown that cell mitosis occurs at a specific time of day in animal tissues in vivo (2)(3)(4)(47)(48)(49), suggesting that the timing of cell mitosis is gated by the circadian cycle. Therefore, we hypothesized that there would be a consistent phase relationship between the circadian and cellcycle rhythms in cultured cells.…”

Section: Resultsmentioning

confidence: 99%

Circadian-independent cell mitosis in immortalized fibroblasts

Yeom

Pendergast

Ohmiya

et al. 2010

Proc. Natl. Acad. Sci. U.S.A.

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Two prominent timekeeping systems, the cell cycle, which controls cell division, and the circadian system, which controls 24-h rhythms of physiology and behavior, are found in nearly all living organisms. A distinct feature of circadian rhythms is that they are temperaturecompensated such that the period of the rhythm remains constant (∼24 h) at different ambient temperatures. Even though the speed of cell division, or growth rate, is highly temperature-dependent, the cell-mitosis rhythm is temperature-compensated. Twenty-fourhour fluctuations in cell division have also been observed in numerous species, suggesting that the circadian system is regulating the timing of cell division. We tested whether the cell-cycle rhythm was coupled to the circadian system in immortalized rat-1 fibroblasts by monitoring cell-cycle gene promoter-driven luciferase activity. We found that there was no consistent phase relationship between the circadian and cell cycles, and that the cell-cycle rhythm was not temperature-compensated in rat-1 fibroblasts. These data suggest that the circadian system does not regulate the cell-mitosis rhythm in rat-1 fibroblasts. These findings are inconsistent with numerous studies that suggest that cell mitosis is regulated by the circadian system in mammalian tissues in vivo. To account for this discrepancy, we propose two possibilities: (i) There is no direct coupling between the circadian rhythm and cell cycle but the timing of cell mitosis is synchronized with the rhythmic host environment, or (ii) coupling between the circadian rhythm and cell cycle exists in normal cells but it is disconnected in immortalized cells.O rganization of physiology and behavior into specific time domains is a fundamental property of nearly all living organisms. Anticipation of periodic changes in the environment presumably increased survival and reinforced the development of endogenous circadian oscillators (1). Because cell division is critical to the survival of unicellular organisms and the integrity of DNA is susceptible to UV irradiation, the progression of the cell cycle was probably also strongly affected by daily changes in the environment. Indeed, multiple studies have measured diurnal fluctuations in cell division such that mitosis occurs at a specific time of day in numerous species ranging from unicellular organisms (2) to humans (3-5). These data suggest that the circadian and cell cycles may be coupled in vivo.Circadian rhythms are self-sustained oscillations in physiology and behavior with endogenous periods of ≈24 h that can be synchronized, or entrained, to environmental cues such as the light/dark cycle or temperature (6). In mammals, the master circadian clock is located in the suprachiasmatic nuclei (SCN) of the anterior hypothalamus. Genes that are important for circadian timekeeping are expressed not only in the SCN but also in many peripheral tissues, including fibroblasts (7-11). Immortalized embryonic fibroblasts exhibit circadian rhythms of gene expression (12) and, using singlecell imaging...

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“…There are substantial evidences that progression through the cell cycle occurs at specific times of the day/night cycle, suggesting that a function of the circadian clock system is to control this fundamental process. 42,[48][49][50] Indeed, microarray analyses revealed that key elements of the cell cycle machinery including cyclin D1, cyclin B1, cyclin E, cyclin A, P53, Wee1, c-myc, Mdm2 and Gadd45 exhibit circadian-dependent expression (Table 2). 51 …”

Section: Clock-related Genes Regulate the Transcription Of Cell Cyclementioning

confidence: 99%

Cell “circadian” cycle: New role for mammalian core clock genes

Borgs¹,

Beukelaers²,

Vandenbosch³

et al. 2009

Cell Cycle

109

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In mammals, 24 hours rhythms are organized as a biochemical network of molecular clocks that are operative in all tissues, with the master clock residing in the hypothalamic suprachiasmatic nucleus (SCN). The core pacemakers of these clocks consist of auto-regulatory transcriptional/post-transcriptional feedback loops. Several lines of evidence suggest the existence of a crosstalk between molecules that are responsible for the generation of circadian rhythms and molecules that control the cell cycle progression. In addition, highly specialized cell cycle checkpoints involved in DNA repair after damage seem also, at least in part, mediated by clock proteins. Recent studies have also highlighted a putative connection between clock protein dysfunction and cancer progression. This review discusses the intimate relation that exists between cell cycle progression and components of the circadian machinery.

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Chronobiology of the intestinal tract of the mouse

Cited by 82 publications

References 73 publications

The effects of feeding time and time-restricted feeding on the fattening traits of White Roman geese

The effects of feeding time and time-restricted feeding on the fattening traits of White Roman geese

Circadian-independent cell mitosis in immortalized fibroblasts

Cell “circadian” cycle: New role for mammalian core clock genes

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