Abstract：
:The authors analyzed the upstream regulatory region of purF, a gene that is expressed in a minority phase that peaks at dawn (class 2 circadian phasing) in Synechococcus elongatus, to determine whether specific cis elements are responsible for this characteristic expression pattern. Fusions of various promoter-bearing fragments to luciferase reporter genes showed that normal class 2 phasing of purF expression was correlated with promoter strength. No specific cis element that is separable from the promoter was responsible for determining phase. Very weak promoter activity of unstable phasing was mapped to a 50-bp segment. Inclusion of sequences that flank this minimal promoter either upstream or downstream increased the promoter strength and stabilized the phase in class 2, but neither segment was individually necessary. Because the data suggested a role for the overall promoter context rather than a specific "phase element," the authors proposed that DNA topology is important in the phase determination of circadian gene expression in S. elongatus. To test this hypothesis, they fused the well-characterized DNA topology-dependent Escherichia coli fis promoter to luciferase and showed that it acts as a class 2 promoter in S. elongatus.
journal_name
J Biol Rhythmsjournal_title
Journal of biological rhythmsauthors
Min H,Liu Y,Johnson CH,Golden SSdoi
10.1177/0748730403262056subject
Has Abstractpub_date
2004-04-01 00:00:00pages
103-12issue
2eissn
0748-7304issn
1552-4531journal_volume
19pub_type
杂志文章abstract：:The temporal expression pattern of the circadian clock gene period was compared between heads of the linden bug, Pyrrhocoris apterus , kept under diapause-promoting short days (SD) and diapause-preventing long days (LD) using a real-time PCR quantification. Diapause or reproduction was programmed by photoperiod during...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730407303624
更新日期：2007-08-01 00:00:00
abstract：:The light preferences of fruit flies were tested by 2 different means. First, flies were allowed to choose between different illuminations, and their favorite resting, grooming, and feeding places were determined with an infrared-sensitive camera. Second, the activity levels of the animals during their main daily acti...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730407306198
更新日期：2007-10-01 00:00:00
abstract：:Daylight saving time (DST) is a source of circadian disruption impinging on millions of people every year. Our aim was to assess modifications, if any, in the number, type, and outcome of Accident & Emergency (A&E) visits/return visits over the DST months. The study included 366,527 visits and 84,380 return visits to ...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730418791097
更新日期：2018-10-01 00:00:00
abstract：:The mammalian endogenous circadian clock, the suprachiasmatic nuclei, receives environmental inputs, namely the light-dark cycle, through photopigments located in the eye and from melanopsin-expressing retinal ganglion cells. The authors investigated the influence of light wavelength and intensity on the synchronizati...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730410368244
更新日期：2010-06-01 00:00:00
abstract：:The human circadian timing system has previously been shown to free run with a period slightly longer than 24 h in subjects living in the laboratory under conditions of forced desynchrony. In forced desynchrony, subjects are shielded from bright light and periodic time cues and are required to live on a day length out...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873099129000597
更新日期：1999-06-01 00:00:00
abstract：:Sex differences in circadian rhythms have been reported with some conflicting results. The timing of sleep and length of time in bed have not been considered, however, in previous such studies. The current study has 3 major aims: (1) replicate previous studies in a large sample of young adults for sex differences in s...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730413511771
更新日期：2013-12-01 00:00:00
abstract：:Rats anticipate a fixed daily feeding time by entrainment of a component of their multioscillatory circadian system. The range of stimuli capable of entraining this component is little studied. Previous studies suggest that restricted water access is not an effective entrainment stimulus, as measured by general locomo...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873049200700206
更新日期：1992-07-01 00:00:00
abstract：:Male rose-ringed parakeets (Psittacula krameri) were transferred to a long photoperiod (LP; LD 16:8) or a short photoperiod (SP; LD 8:16) for 45 or 90 days on four dates corresponding to the beginnings of different reproductive phases in an annual testicular cycle, and testicular responsiveness was evaluated by compar...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873049200700102
更新日期：1992-04-01 00:00:00
abstract：:Endogenous circadian rhythms are involved in various photoperiodic responses of birds. Investigations involving the mechanisms of photoperiodic time measurement in birds have been confined mainly to temperate zone species using males exclusively. Due to the paucity of experimental evidence on subtropical birds that ha...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873049501000405
更新日期：1995-12-01 00:00:00
abstract：:Obesity during pregnancy causes numerous maternal and fetal health complications, but the underlying mechanisms remain unclear. Adipose tissue dysfunction in obesity has previously been linked to disruption of the intrinsic adipose clock gene network that is crucial for normal metabolic function. This adipose clock al...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730418772499
更新日期：2018-06-01 00:00:00
abstract：:Crustaceans have frequently been used to study the neuroethology of both agonistic behavior and circadian rhythms, but whether their highly stereotyped and quantifiable agonistic activity is controlled by circadian pacemakers has, so far, not been investigated. Isolated marbled crayfish (Procambarus spec.) displayed r...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730408328933
更新日期：2009-02-01 00:00:00
abstract：:Rhodopsin 7 ( Rh7), a new invertebrate Rhodopsin gene, was discovered in the genome of Drosophila melanogaster in 2000, but its function has remained elusive. We generated an Rh7 null mutant ( Rh70) by P element-mediated mutagenesis and found that an absence of Rh7 had significant effects on fly activity patterns duri...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730417721826
更新日期：2017-10-01 00:00:00
abstract：:Numerous studies have used the classic van der Pol oscillator, which contains a cubic nonlinearity, to model the effect of light on the human circadian pacemaker. Jewett and Kronauer demonstrated that Aschoff's rule could be incorporated into van der Pol type models and used a van der Pol type oscillator with higher o...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873099129000867
更新日期：1999-12-01 00:00:00
abstract：:The suprachiasmatic nucleus (SCN) drives circadian rhythms in locomotion through coupled, single-cell oscillations. Global genetic deletion of the neuropeptide Vip or its receptor Vipr2 results in profound deficits in daily synchrony among SCN cells and daily rhythms in locomotor behavior and glucocorticoid secretion....
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730420932073
更新日期：2020-10-01 00:00:00
abstract：:The possibility that feeding may act as a zeitgeber has been investigated in captive Svalbard ptarmigan by recording feeding or food-searching activity (FA) in birds given periodic access to food (PAF) under light-dark (LD) cycles or in continuous bright (LL) or dim light (DD) conditions. Except during LL, anticipator...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873049801300504
更新日期：1998-10-01 00:00:00
abstract：:The endogenous circadian rhythm of melatonin in humans provides information regarding the resetting response of the human circadian timing system to changes in the light-dark (LD) cycle. Alterations in the LD cycle have both acute and chronic effects on the observed melatonin rhythm. Investigations to date have firmly...
journal_title：Journal of biological rhythms
pub_type： 杂志文章,评审
doi：10.1177/074873049701200610
更新日期：1997-12-01 00:00:00
abstract：:The hematologic system performs a number of essential functions, including oxygen transport, the execution of the immune response against tumor cells and invading pathogens, and hemostasis (blood clotting). These roles are performed by erythrocytes (red blood cells), leukocytes (white blood cells), and thrombocytes (p...
journal_title：Journal of biological rhythms
pub_type： 杂志文章,评审
doi：10.1177/0748730415592729
更新日期：2015-10-01 00:00:00
abstract：:In mammals, molecular circadian rhythms are generated by autoregulatory transcriptional-translational feedback loops with PERIOD/CRYPTOCHROME containing complexes inhibiting the transcription of their own genes. Although the major circadian oscillator components seem to be identified, an increasing number of additiona...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730415587407
更新日期：2015-08-01 00:00:00
abstract：:Aging alters numerous aspects of circadian biology, including the amplitude of rhythms generated by the suprachiasmatic nuclei (SCN) of the hypothalamus, the site of the central circadian pacemaker in mammals, and the response of the pacemaker to environmental stimuli such as light. Although previous studies have desc...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730403251802
更新日期：2003-04-01 00:00:00
abstract：:Threads of evidence from recent experimentation in retinal morphology, neurochemistry, electrophysiology, and visual perception point toward rhythmic ocular processes that may be integral components of circadian entrainment in mammals. Components of retinal cell biology (rod outer-segment disk shedding, inner-segment ...
journal_title：Journal of biological rhythms
pub_type： 杂志文章,评审
doi：10.1177/074873049100600104
更新日期：1991-04-01 00:00:00
abstract：:Intertidal species have both circadian and circatidal clocks. Although the behavioral evidence for these oscillators is more than 5 decades old, virtually nothing is known about their molecular clockwork. Pigment-dispersing hormones (PDHs) were originally described in crustaceans. Their insect homologs, pigment-disper...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730411420242
更新日期：2011-12-01 00:00:00
abstract：:The SCN has long had organizational schemas imposed on it. In most, the SCN is dichotomized, with one region typically associated with the presence of vasopressin cells and the other associated with cells containing vasoactive intestinal polypeptide and certain afferent terminal fields. If assumed to be accurate, the ...
journal_title：Journal of biological rhythms
pub_type： 杂志文章,评审
doi：10.1177/0748730406296749
更新日期：2007-02-01 00:00:00
abstract：:Although pineal "synaptic" ribbons (SR) are frequently examined by means of quantitative electron microscopy, their functional significance remains unclear. The same is true for related structures--"synaptic" spherules (SPH). In the course of such studies, it has been noted that SR counts may differ from laboratory to...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873048800300103
更新日期：1988-04-01 00:00:00
abstract：:Honey bee (Apis mellifera) workers emerge from the pupae with no circadian rhythms in behavior or brain clock gene expression but show strong rhythms later in life. This postembryonic development of circadian rhythms is reminiscent of that of infants of humans and other primates but contrasts with most insects, which ...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730412440851
更新日期：2012-06-01 00:00:00
abstract：:Individuals of the shore crab Carcinus maenas were exposed to artificial cycles, applied in tidal antiphase, of pairs of the three major environmental variables that entrain circatidal rhythmicity in this species: salinity, temperature, and hydrostatic pressure. During entrainment, the observed locomotor activity patt...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873049000500405
更新日期：1990-01-01 00:00:00
abstract：:Entrainability of the circadian rhythm of mosquito flight and locomotor activity was investigated by giving a 24-hr temperature cycle (28 degrees C for 16 hr, 23 degrees C for 8 hr) to the free-running rhythm or by shifting the temperature cycle. The phase angle difference between the entrained rhythm and the temperat...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873049300800304
更新日期：1993-10-01 00:00:00
abstract：:Photic signals affect circadian activity rhythms by both phasic and tonic mechanisms that modulate pacemaker phase and period. In mammals, the effects of light on circadian activity are mediated by the retina, which communicates with the suprahiasmatic nucleus (SCN) by two different anatomical routes: the retino-hypot...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873048700200104
更新日期：1987-04-01 00:00:00
abstract：:The frequency demultiplication hypothesis (FDH) posits that circannual rhythms are generated from circadian cycles by frequency transformation to the lower-frequency rhythm. To test the FDH, we determined the periods of the circannual body mass and estrous cycles of golden-mantled ground squirrels with circadian locom...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/074873048600100402
更新日期：1986-01-01 00:00:00
abstract：:During the first 7 weeks of postnatal life, short day lengths inhibit the onset of puberty in many photoperiodic rodents, but not in Syrian hamsters. In this species, timing of puberty and fecundity are independent of the early postnatal photoperiod. Gestational day length affects postnatal reproductive development in...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730408322985
更新日期：2008-10-01 00:00:00
abstract：:Seasonal changes in numerous aspects of mammalian immune function arise as a result of the annual variation in environmental day length (photoperiod), but it is not known if absolute photoperiod or relative change in photoperiod drives these changes. This experiment tested the hypothesis that an individual's history o...
journal_title：Journal of biological rhythms
pub_type： 杂志文章
doi：10.1177/0748730409349714
更新日期：2009-12-01 00:00:00
