Biological mechanism that controls CIRCADIAN RHYTHM. Circadian clocks exist in the simplest form in cyanobacteria and as more complex systems in fungi, plants, and animals. In humans the system includes photoresponsive RETINAL GANGLION CELLS and the SUPRACHIASMATIC NUCLEUS that acts as the central oscillator.
Basic helix-loop-helix (bHLH) domain-containing proteins that contain intrinsic HISTONE ACETYLTRANSFERASE activity and play important roles in CIRCADIAN RHYTHM regulation. Clock proteins combine with Arntl proteins to form heterodimeric transcription factors that are specific for E-BOX ELEMENTS and stimulate the transcription of several E-box genes that are involved in cyclical regulation. This transcriptional activation also sets into motion a time-dependent feedback loop which in turn down-regulates the expression of clock proteins.
The regular recurrence, in cycles of about 24 hours, of biological processes or activities, such as sensitivity to drugs and stimuli, hormone secretion, sleeping, and feeding.
The physiological mechanisms that govern the rhythmic occurrence of certain biochemical, physiological, and behavioral phenomena.
Circadian rhythm signaling proteins that influence circadian clock by interacting with other circadian regulatory proteins and transporting them into the CELL NUCLEUS.
Basic helix-loop-helix (bHLH) domain-containing proteins that play important roles in CIRCADIAN RHYTHM regulation. They combine with CLOCK PROTEINS to form heterodimeric transcription factors that are specific for E-BOX ELEMENTS and stimulate the transcription of several E-box genes that are involved in cyclical regulation.
Flavoproteins that function as circadian rhythm signaling proteins in ANIMALS and as blue-light photoreceptors in PLANTS. They are structurally-related to DNA PHOTOLYASES and it is believed that both classes of proteins may have originated from an earlier protein that played a role in protecting primitive organisms from the cyclical exposure to UV LIGHT.
The time period of daily exposure that an organism receives from daylight or artificial light. It is believed that photoperiodic responses may affect the control of energy balance and thermoregulation.
A broad category of proteins that regulate the CIRCADIAN RHYTHM of an organism. Included here are proteins that transmit intracellular and intercellular signals in a chronological manner along with proteins that sense light and time-dependent changes in the environment such as the PHOTOPERIOD.
An ovoid densely packed collection of small cells of the anterior hypothalamus lying close to the midline in a shallow impression of the OPTIC CHIASM.
That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.
A DNA-binding orphan nuclear receptor that negatively regulates expression of ARNTL TRANSCRIPTION FACTORS and plays a role as a regulatory component of the circadian clock system. The Nr1d1 nuclear receptor expression is cyclically-regulated by a feedback loop involving its positive regulation by CLOCK PROTEIN; BMAL1 PROTEIN heterodimers and its negative regulation by CRYPTOCHROME and PERIOD PROTEINS.
The absence of light.
A mechanism of communication with a physiological system for homeostasis, adaptation, etc. Physiological feedback is mediated through extensive feedback mechanisms that use physiological cues as feedback loop signals to control other systems.
Disruptions of the rhythmic cycle of bodily functions or activities.
A plant genus of the family BRASSICACEAE that contains ARABIDOPSIS PROTEINS and MADS DOMAIN PROTEINS. The species A. thaliana is used for experiments in classical plant genetics as well as molecular genetic studies in plant physiology, biochemistry, and development.
Proteins that originate from plants species belonging to the genus ARABIDOPSIS. The most intensely studied species of Arabidopsis, Arabidopsis thaliana, is commonly used in laboratory experiments.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action in plants.
A casein kinase I isoenzyme with specificity for proteins involved the regulation of the CIRCADIAN RHYTHM.
Endogenous substances, usually proteins, which are effective in the initiation, stimulation, or termination of the genetic transcription process.
Specialized cells in the invertebrates that detect and transduce light. They are predominantly rhabdomeric with an array of photosensitive microvilli. Illumination depolarizes invertebrate photoreceptors by stimulating Na+ influx across the plasma membrane.
A family of DNA-binding transcription factors that contain a basic HELIX-LOOP-HELIX MOTIF.
Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control (induction or repression) of gene action at the level of transcription or translation.
A form-genus of spherical to rod-shaped CYANOBACTERIA in the order Chroococcales. They contain THYLAKOIDS and are found in a wide range of habitats.
Proteins that originate from insect species belonging to the genus DROSOPHILA. The proteins from the most intensely studied species of Drosophila, DROSOPHILA MELANOGASTER, are the subject of much interest in the area of MORPHOGENESIS and development.
A species of ascomycetous fungi of the family Sordariaceae, order SORDARIALES, much used in biochemical, genetic, and physiologic studies.
Bouts of physical irritability or movement alternating with periods of quiescence. It includes biochemical activity and hormonal activity which may be cellular. These cycles are shorter than 24 hours and include sleep-wakefulness cycles and the periodic activation of the digestive system.
Proteins found in the nucleus of a cell. Do not confuse with NUCLEOPROTEINS which are proteins conjugated with nucleic acids, that are not necessarily present in the nucleus.
The conversion of absorbed light energy into molecular signals.
A biogenic amine that is found in animals and plants. In mammals, melatonin is produced by the PINEAL GLAND. Its secretion increases in darkness and decreases during exposure to light. Melatonin is implicated in the regulation of SLEEP, mood, and REPRODUCTION. Melatonin is also an effective antioxidant.
The physical activity of a human or an animal as a behavioral phenomenon.
DNA locations with the consensus sequence CANNTG. ENHANCER ELEMENTS may contain multiple copies of this element. E-boxes play a regulatory role in the control of transcription. They bind with basic helix-loop-helix (bHLH) type TRANSCRIPTION FACTORS. Binding specificity is determined by the specific bHLH heterodimer or homodimer combination and by the specific nucleotides at the 3rd and 4th position of the E-box sequence.
A light-sensitive neuroendocrine organ attached to the roof of the THIRD VENTRICLE of the brain. The pineal gland secretes MELATONIN, other BIOGENIC AMINES and NEUROPEPTIDES.
A casein kinase I isoenzyme that plays a regulatory role in a variety of cellular functions including vesicular transport, CHROMOSOME SEGREGATION; CYTOKINESIS, developmental processes, and the CIRCADIAN RHYTHM.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
A chronobiologic disorder resulting from rapid travel across a number of time zones, characterized by insomnia or hypersomnolence, fatigue, behavioral symptoms, headaches, and gastrointestinal disturbances. (From Cooper, Sleep, 1994, pp593-8)
The adaptation of drug administration to the known variations in biological RHYTHMICITY, such as CIRCADIAN RHYTHMS. The treatment is aimed at supporting normal rhythms, or modifying the timing of therapy to achieve maximal efficacy and minimal adverse effect.
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
The measurement of frequency or oscillation changes.
Proteins that control the CELL DIVISION CYCLE. This family of proteins includes a wide variety of classes, including CYCLIN-DEPENDENT KINASES, mitogen-activated kinases, CYCLINS, and PHOSPHOPROTEIN PHOSPHATASES as well as their putative substrates such as chromatin-associated proteins, CYTOSKELETAL PROTEINS, and TRANSCRIPTION FACTORS.
Warm-blooded vertebrate animals belonging to the class Mammalia, including all that possess hair and suckle their young.
The tendency of a phenomenon to recur at regular intervals; in biological systems, the recurrence of certain activities (including hormonal, cellular, neural) may be annual, seasonal, monthly, daily, or more frequently (ultradian).
A genus of ascomycetous fungi, family Sordariaceae, order SORDARIALES, comprising bread molds. They are capable of converting tryptophan to nicotinic acid and are used extensively in genetic and enzyme research. (Dorland, 27th ed)
Diffusible gene products that act on homologous or heterologous molecules of viral or cellular DNA to regulate the expression of proteins.
The reproductive organs of plants.
A genus of small, two-winged flies containing approximately 900 described species. These organisms are the most extensively studied of all genera from the standpoint of genetics and cytology.
An acetyltransferase with specificity towards the amine group of aromatic alkylamines (arylalkylamines) such as SEROTONIN. This enzyme is also referred to as serotonin acetylase despite the fact that serotonin acetylation can also occur through the action of broad specificity acetyltransferases such as ARYLAMINE N-ACETYLTRANSFERASE.
The region of the stem beneath the stalks of the seed leaves (cotyledons) and directly above the young root of the embryo plant. It grows rapidly in seedlings showing epigeal germination and lifts the cotyledons above the soil surface. In this region (the transition zone) the arrangement of vascular bundles in the root changes to that of the stem. (From Concise Dictionary of Biology, 1990)
A species of fruit fly much used in genetics because of the large size of its chromosomes.
The functional hereditary units of PLANTS.
Seasonal suspension of insect growth development. It can be either induced by environmental cues (e.g., PHOTOPERIOD) or as a facultative part of the life cycle in order to time development with seasonal changes.
RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3' end, referred to as the poly(A) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm.
A blue-green biliprotein widely distributed in the plant kingdom.
The biosynthesis of RNA carried out on a template of DNA. The biosynthesis of DNA from an RNA template is called REVERSE TRANSCRIPTION.
Enzymes that oxidize certain LUMINESCENT AGENTS to emit light (PHYSICAL LUMINESCENCE). The luciferases from different organisms have evolved differently so have different structures and substrates.
A phylum of oxygenic photosynthetic bacteria comprised of unicellular to multicellular bacteria possessing CHLOROPHYLL a and carrying out oxygenic PHOTOSYNTHESIS. Cyanobacteria are the only known organisms capable of fixing both CARBON DIOXIDE (in the presence of light) and NITROGEN. Cell morphology can include nitrogen-fixing heterocysts and/or resting cells called akinetes. Formerly called blue-green algae, cyanobacteria were traditionally treated as ALGAE.
The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.
The branch of biology dealing with the effect of light on organisms.
ANIMALS whose GENOME has been altered by GENETIC ENGINEERING, or their offspring.
A plant photo regulatory protein that exists in two forms that are reversibly interconvertible by LIGHT. In response to light it moves to the CELL NUCLEUS and regulates transcription of target genes. Phytochrome B plays an important role in shade avoidance and mediates plant de-etiolation in red light.
Elements of limited time intervals, contributing to particular results or situations.
A continuous cell line of high contact-inhibition established from NIH Swiss mouse embryo cultures. The cells are useful for DNA transfection and transformation studies. (From ATCC [Internet]. Virginia: American Type Culture Collection; c2002 [cited 2002 Sept 26]. Available from http://www.atcc.org/)
A DNA-binding orphan nuclear receptor that positively regulates expression of ARNTL TRANSCRIPTION FACTORS and is a regulatory component of the circadian clock system. The protein also has a role in neuron cell survival and differentiation in that loss of function mutations of its gene result in the mouse phenotype referred to as the STAGGERER MOUSE.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Emission of LIGHT when ELECTRONS return to the electronic ground state from an excited state and lose the energy as PHOTONS. It is sometimes called cool light in contrast to INCANDESCENCE. LUMINESCENT MEASUREMENTS take advantage of this type of light emitted from LUMINESCENT AGENTS.
Biological systems as affected by time. Aging, biological rhythms, and cyclic phenomena are included. Statistical, computer-aided mathematical procedures are used to describe, in mathematical terminology, various biological functions over time.
A casein kinase that was originally described as a monomeric enzyme with a molecular weight of 30-40 kDa. Several ISOENZYMES of casein kinase I have been found which are encoded by separate genes. Many of the casein kinase I isoenzymes have been shown to play distinctive roles in intracellular SIGNAL TRANSDUCTION.
The observable response an animal makes to any situation.
Photosensitive proteins expressed in the ROD PHOTORECEPTOR CELLS. They are the protein components of rod photoreceptor pigments such as RHODOPSIN.
Dyssomnias associated with disruption of the normal 24 hour sleep wake cycle secondary to travel (e.g., JET LAG SYNDROME), shift work, or other causes.
Ribonucleic acid in plants having regulatory and catalytic roles as well as involvement in protein synthesis.
The adaptation of therapeutic approaches such as pharmacological (DRUG CHRONOTHERAPY), surgical, radiological, or physical to the known variations in biological RHYTHMICITY, such as CIRCADIAN RHYTHMS. The treatment is aimed at supporting normal rhythms, or modifying the timing of therapy to achieve maximal efficacy and minimal adverse effect.
The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.
A mechanism of communication within a system in that the input signal generates an output response which returns to influence the continued activity or productivity of that system.
PLANTS, or their progeny, whose GENOME has been altered by GENETIC ENGINEERING.
Peptides released by NEURONS as intercellular messengers. Many neuropeptides are also hormones released by non-neuronal cells.
A readily reversible suspension of sensorimotor interaction with the environment, usually associated with recumbency and immobility.
DNA sequences which are recognized (directly or indirectly) and bound by a DNA-dependent RNA polymerase during the initiation of transcription. Highly conserved sequences within the promoter include the Pribnow box in bacteria and the TATA BOX in eukaryotes.
The group of celestial bodies, including the EARTH, orbiting around and gravitationally bound by the sun. It includes eight planets, one minor planet, and 34 natural satellites, more than 1,000 observed comets, and thousands of lesser bodies known as MINOR PLANETS (asteroids) and METEOROIDS. (From Academic American Encyclopedia, 1983)
A genus of the family Muridae having three species. The present domesticated strains were developed from individuals brought from Syria. They are widely used in biomedical research.
Proteins found in any species of insect.
The largest family of cell surface receptors involved in SIGNAL TRANSDUCTION. They share a common structure and signal through HETEROTRIMERIC G-PROTEINS.
The introduction of a phosphoryl group into a compound through the formation of an ester bond between the compound and a phosphorus moiety.
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
Behavioral responses or sequences associated with eating including modes of feeding, rhythmic patterns of eating, and time intervals.
Proteins which bind to DNA. The family includes proteins which bind to both double- and single-stranded DNA and also includes specific DNA binding proteins in serum which can be used as markers for malignant diseases.
Strains of mice in which certain GENES of their GENOMES have been disrupted, or "knocked-out". To produce knockouts, using RECOMBINANT DNA technology, the normal DNA sequence of the gene being studied is altered to prevent synthesis of a normal gene product. Cloned cells in which this DNA alteration is successful are then injected into mouse EMBRYOS to produce chimeric mice. The chimeric mice are then bred to yield a strain in which all the cells of the mouse contain the disrupted gene. Knockout mice are used as EXPERIMENTAL ANIMAL MODELS for diseases (DISEASE MODELS, ANIMAL) and to clarify the functions of the genes.
Movement or the ability to move from one place or another. It can refer to humans, vertebrate or invertebrate animals, and microorganisms.
The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the NERVOUS SYSTEM.
Techniques used for determining the values of photometric parameters of light resulting from LUMINESCENCE.
The functional hereditary units of INSECTS.
The natural satellite of the planet Earth. It includes the lunar cycles or phases, the lunar month, lunar landscapes, geography, and soil.
The physiological processes, properties, and states characteristic of plants.
The determination of the pattern of genes expressed at the level of GENETIC TRANSCRIPTION, under specific circumstances or in a specific cell.
Proteins found in any species of fungus.
A plant family of the order Fagales subclass Hamamelidae, class Magnoliopsida.
An exotic species of the family CYPRINIDAE, originally from Asia, that has been introduced in North America. They are used in embryological studies and to study the effects of certain chemicals on development.
A suborder of HEMIPTERA, called true bugs, characterized by the possession of two pairs of wings. It includes the medically important families CIMICIDAE and REDUVIIDAE. (From Dorland, 28th ed)
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
The illumination of an environment and the arrangement of lights to achieve an effect or optimal visibility. Its application is in domestic or in public settings and in medical and non-medical environments.
The primary plant photoreceptor responsible for perceiving and mediating responses to far-red light. It is a PROTEIN-SERINE-THREONINE KINASE that is translocated to the CELL NUCLEUS in response to light signals.
The processes whereby the internal environment of an organism tends to remain balanced and stable.
The relationships of groups of organisms as reflected by their genetic makeup.
The ten-layered nervous tissue membrane of the eye. It is continuous with the OPTIC NERVE and receives images of external objects and transmits visual impulses to the brain. Its outer surface is in contact with the CHOROID and the inner surface with the VITREOUS BODY. The outer-most layer is pigmented, whereas the inner nine layers are transparent.
Proteins found in plants (flowers, herbs, shrubs, trees, etc.). The concept does not include proteins found in vegetables for which VEGETABLE PROTEINS is available.
A pituitary adenylate cyclase-activating peptide receptor subtype found in LYMPHOCYTES. It binds both PACAP and VASOACTIVE INTESTINAL PEPTIDE and regulates immune responses.
The phenotypic manifestation of a gene or genes by the processes of GENETIC TRANSCRIPTION and GENETIC TRANSLATION.
A state in which there is an enhanced potential for sensitivity and an efficient responsiveness to external stimuli.
A family of G-protein-coupled receptors that are specific for and mediate the effects of MELATONIN. Activation of melatonin receptors has been associated with decreased intracellular CYCLIC AMP and increased hydrolysis of PHOSPHOINOSITIDES.
Specialized cells that detect and transduce light. They are classified into two types based on their light reception structure, the ciliary photoreceptors and the rhabdomeric photoreceptors with MICROVILLI. Ciliary photoreceptor cells use OPSINS that activate a PHOSPHODIESTERASE phosphodiesterase cascade. Rhabdomeric photoreceptor cells use opsins that activate a PHOSPHOLIPASE C cascade.
A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.
A family of proteins that share the F-BOX MOTIF and are involved in protein-protein interactions. They play an important role in process of protein ubiquition by associating with a variety of substrates and then associating into SCF UBIQUITIN LIGASE complexes. They are held in the ubiquitin-ligase complex via binding to SKP DOMAIN PROTEINS.
A form-genus of unicellular coccoid to rod-shaped CYANOBACTERIA, in the order Chroococcales. Three different clusters of strains from diverse habitats are included.

Circadian clock resetting in the mouse changes with age. (1/573)

 (+info)

Chronopharmaceutical drug delivery systems: Hurdles, hype or hope? (2/573)

 (+info)

Interplay between low-temperature pathways and light reduction. (3/573)

Low temperature is one of the major factors that adversely affect crop yields by causing restraints on plant growth and productivity. However, most temperate plants have the ability to acclimate to cooler temperatures. Cold acclimation is a process which increases the freezing tolerance of an organism after exposure to low, non-freezing temperatures. The main trigger is a decrease in temperature levels, but light reduction has also been shown to have an important impact on acquired tolerance. Since the lowest temperatures are commonly reached during the night hours in winter time and is an annually recurring event, a favorable trait for plants is the possibility of sensing an imminent cold period. Consequently, extensive crosstalk between light- and temperature signaling pathways has been demonstrated and in this review interesting interaction points that have been previously reported in the literature are highlighted.  (+info)

Heritable circadian period length in a wild bird population. (4/573)

 (+info)

Circadian rhythms in gene expression: Relationship to physiology, disease, drug disposition and drug action. (5/573)

 (+info)

PERsuading nuclear receptors to dance the circadian rhythm. (6/573)

The recurring light/dark cycle that has a period length of about 24 hours has been internalized in various organisms in the form of a circadian clock. This clock allows a precise orchestration of biochemical and physiological processes in the body thus improving performance. Recently, we found that the clock component PERIOD2 (PER2) can coordinate transcriptional regulation of metabolic, physiological, or behavioral pathways by interacting with nuclear receptors. PER2 appears to act as co-regulator of nuclear receptors linking clock function and transcriptional regulation at the level of protein-protein interactions. Here, we provide additional evidence for modulation of nuclear receptor dependent transcription by PER2 underscoring the broad implication of our finding. Taken together, our findings provide a base for the understanding of various disorders including mood disorders that have their roots in a temporal deregulation of basic metabolic processes.  (+info)

Circadian clocks in the ovary. (7/573)

 (+info)

Similarities in the circadian clock and photoperiodism in plants. (8/573)

 (+info)

The identification of circadian clocks in endocrine tissues has added considerable depth and complexity to our understanding of their physiology. A growing body of research reveals circadian clock gene expression in the uterus of non-pregnant and pregnant mammals. A key study to draw attention to the potential role of the circadian clock and pregnancy was that of Miller et al (2004), who reported that pregnant mice lacking the functional Clock gene (ClockΔ19) had prolonged and non-productive parturition, suggestive of a role for circadian clocks in the parturition event. Nakamura et al. (2010) showed changes in Per2::LUC rhythmic phase and amplitude in uterine explants treated with estrogen and progesterone. These results are consistent with the idea that ovarian steroid levels during the estrous cycle have a modulating influence of clock gene expression in the uterus. Ratajczak et al. (2010) examined expression of circadian clock genes in the mouse uterus in late pregnancy and
The circadian clock is an endogenous time-keeping system that coordinates the physiology and behavior of a living organism to its environment [1]. In plants, the clock modulates rhythmic leaf movement, elongation rate of hypocotyls, roots, and stems, stomata aperture, stem circumnutation, and flower opening [1, 2].. Three major interlocked feedback loops constitute the plant circadian clock: the central loop, the morning loop, and the evening loop [3-5]. The central loop is mediated by the reciprocal repression between the morning-phased MYB transcription factors, CIRCADIAN CLOCK ASSOCIATED 1 (CCA1) and LATE ELONGATED HYPOCOTYL (LHY), and the evening-phased pseudo-response regulator TIMING OF CAB EXPRESSION 1 (TOC1) [6, 7]. In the morning loop, CCA1 and LHY promote the transcription of PSEUDO-RESPONSE REGULATOR 9 (PRR9) and PRR7 genes [8, 9]. Closing the loop, the PRR members inhibit the transcription of CCA1 and LHY genes by sequentially binding to the gene promoters from early morning (PRR9) ...
Circadian clocks are molecular oscillators with ~24-hour periods that drive daily biological rhythms. Such clocks are found in all of the major branches of life, and they likely represent ancient timekeeping systems important for predicting daily environmental cycles on our rotating planet. In mammals, circadian clocks are present in most if not all cells. These distributed clocks control a myriad of processes, in aggregate creating coherent 24-hour programs of physiology and behavior.. A picture of how circadian clocks are built has emerged in the last two decades. The core mechanism is a transcriptional feedback loop, wherein the protein products of several clock genes build the molecular machinery to inhibit the transcription factor responsible for their own production. The molecular components of circadian clocks are conserved from insects to humans.. The Weitz lab uses molecular biology, biochemistry, genetics, and structural biology to investigate the mammalian circadian clock. The focus ...
Marked circadian rhythms in myocardial metabolism are mediated by as yet unidentified mechanism(s). Virtually every mammalian cell possesses an intrinsic circadian clock, a transcriptionally-based molecular mechanism capable of regulating multiple cellular functions. Recent studies suggest that the transcriptional co-activator, PGC1α, is an integral component of the mammalian circadian clock, which links this molecular mechanism to oxidative metabolism. To test the hypothesis that the circadian clock directly influences myocardial metabolism, a cardiomyocyte-specific circadian clock mutant (CCM) mouse was generated. Wild-type (WT) and CCM hearts were isolated and perfused in the working mode, for simultaneous assessment of myocardial contractile function and metabolism. Compared to WT, CCM hearts exhibited decreased cardiac efficiency independent of the time of day (13% lower; p,0.05), with greatest differences observed during the middle of the dark (awake) phase (29% lower; p,0.01). ...
Circadian rhythms control processes ranging from human sleep-wake cycles to cyanobacterial cell division. This is made possible by the circadian clock, an internal biochemical oscillator. The circadian clock allows organisms to anticipate daily changes in the environment such as the onset of dawn and dusk, providing them with an adaptive advantage (1). Physiological processes regulated by the clock in higher plants include photoperiodic induction of flowering (2) and rhythmic hypocotyl elongation, cotyledon movement, and stomatal opening (3). A small number of genes regulated by the clock have been found in an essentially serendipitous fashion (4, 5). However, a global examination of genes controlled by the clock in plants, or in any eukaryote, has been lacking.. The circadian clock regulates hundreds of genes. We have used highly reproducible oligonucleotide-based arrays (6) to determine steady-state mRNA levels inArabidopsis at 4-hour intervals during the subjective day and night. We examined ...
Manipulating Plants Circadian Clock May Make All-Season Crops Possible http://www.sciencedaily.com/releases/2011/09/110901134643.htm...
The circadian clock is an endogenous timekeeper that allows organisms to anticipate and adapt to the daily variations of their environment. The plant clock is an intricate network of interlocked feedback loops, in which transcription factors regulate each other to generate oscillations with expression peaks at specific times of the day. Over the last decade, mathematical modeling approaches have been used to understand the inner workings of the clock in the model plant Arabidopsis thaliana. Those efforts have produced a number of models of ever increasing complexity. Here, we present an alternative model that combines a low number of equations and parameters, similar to the very earliest models, with the complex network structure found in more recent ones. This simple model describes the temporal evolution of the abundance of eight clock genes and captures key features of the clock on a qualitative level, namely the entrained and free-running behaviors of the wild type clock, as well as the defects
Disruption of circadian homeostasis is frequently observed in tumour cells. In a comprehensive study of circadian clock genes in 21 cancer types that takes into account genomic, transcriptomic and phenotypic (clinical prognosis) data, we demonstrated that clock genes were substantially altered by somatically acquired deletions and amplifications. Recurrent deletions or amplifications that were accompanied by altered transcript expression in tumours could represent novel loss- or gain-of-function phenotypes. To exploit these circadian targets in a clinical setting, we analysed survival outcomes using the ClockLoss and ClockGain and confirmed the utility of both gene sets as prognostic tools in 2914 and 2784 patients involving seven diverse cancer cohorts.. Depending on cellular context, the circadian clock can exert both tumour-promoting or tumour-inhibiting properties. We observed that core clock genes, PERs, CRY2, CLOCK, NR1D2, RORA and RORB exhibited global patterns of somatic loss and ...
Our circadian clocks are centered in the brain and control key physiological processes-sleep, body temperature, organ function, and metabolic activities such as maintaining blood glucose levels. Disrupting the clock can potentially lead to diabetes and other metabolic diseases.. In a study involving mice that was published online on June 21 in Cell Metabolism, Rajat Singh, M.D., M.B.B.S., and his team discovered that autophagy-the cellular process for cleaning up and recycling old proteins and other material-helps regulate circadian rhythms and also governs the daily fluctuations in blood glucose levels.. In autophagy, the unwanted material is digested within enzyme-filled structures called lysosomes. The researchers found that autophagic digestion selectively targets proteins controlling the circadian clock, most notably the clock protein CRY1. CRY1 is a key regulator of circadian cycles and also helps maintain blood glucose levels by inhibiting the liver from forming and secreting glucose. The ...
Work by researchers at the universities of Aberdeen and Nottingham suggest an anatomical basis for the adaptation of the mammalian circadian clock to changing day-length. Endogenous circadian clocks ensure that temporal patterns of physiology and behavior predict environmental changes determined by the Earths rotation and orbit of the Sun. Such clocks are synchronized by the daily light-dark cycle.
Video articles in JoVE about circadian clocks include Single-cell Resolution Fluorescence Live Imaging of Drosophila Circadian Clocks in Larval Brain Culture, Parallel Measurement of Circadian Clock Gene Expression and Hormone Secretion in Human Primary Cell Cultures, Monitoring Cell-autonomous Circadian Clock Rhythms of Gene Expression Using Luciferase Bioluminescence Reporters, In Vitro Bioluminescence Assay to Characterize Circadian Rhythm in Mammary Epithelial Cells, Assaying Locomotor Activity to Study Circadian Rhythms and Sleep Parameters in Drosophila, Analysis of Circadian Photoresponses in Drosophila Using Locomotor Activity, Rapid Analysis of Circadian Phenotypes in Arabidopsis Protoplasts Transfected with a Luminescent Clock Reporter, A Computational Method to Quantify Fly Circadian Activity, Desensitization and Recovery of Crayfish Photoreceptors Upon Delivery of a Light Stimulus, Flexible Measurement of Bioluminescent Reporters Using an Automated Longitudinal
article{3062551, abstract = {Previously, we identified HISTONE MONOUBIQUITINATION1 (HUB1) as an unconventional ubiquitin E3 ligase that is not involved in protein degradation but in the histone H2B modification that is implicated in transcriptional activation in plants. HUB1-mediated regulation of gene expression played a role in periodic and inducible processes such as the cell cycle, dormancy, flowering time and defense responses. Here, we determined the effects of the hub1-1 mutation on expression of a set of diurnally induced circadian clock genes identified from a comparative microarray analysis between the hub1-1 mutant and an HUB1 over-expression line. The hub1-1 mutation reduced the amplitudes of a number of induced clock gene expression peaks, as well as the HUB1-mediated histone H2BUb and H3K4Me3 marks associated with the coding regions, suggesting a role for HUB1 in facilitating transcriptional elongation in plants. Furthermore, double mutants between hub1-1 and elongata (elo) showed ...
Circadian clocks, found widely in nature, act to coordinate biological processes with rhythmic changes in the environment. Light input plays an important role in adjusting the clocks phase as well as maintaining its pace, allowing for perception of both daily and seasonal information (Aschoff, 1979). The central biological oscillator interprets this environmental information and transmits the signal to a diverse set of outputs. A substantial portion of the Arabidopsis (Arabidopsis thaliana) transcriptome is clock regulated, with estimates ranging from 2% to 36% of expressed genes (Harmer et al., 2000; Schaffer et al., 2001; Michael and McClung, 2003a; Edwards et al., 2006; M.F. Covington and S.L. Harmer, personal communication).. In the current model of the Arabidopsis oscillator, TIMING OF CHLOROPHYLL A/B BINDING PROTEIN/PSEUDO RESPONSE REGULATOR1 (TOC1/PRR1) is believed to act as part of a central negative feedback loop with CIRCADIAN CLOCK ASSOCIATED (CCA1) and LATE ELONGATED HYPOCOTYL (LHY; ...
The majority of cells in the body have an internal clock which controls cell cycle factors. However, the internal clock of cancer cells is often non-functioning or malfunctioning.. In the study, the team compared the growth and cell cycle events of B16 melanoma cells and tumors with either a functional or dysfunctional clock. The team demonstrated that clock genes are suppressed in B16 melanoma cells and B16 tumors.. The team then went on to successfully adjust the internal clocks of melanoma B16 cells and human colon carcinoma cells, as to make them function normally. The repair, carried out in tissue cultures and mice, slowed the growth of tumor tissue; a week post-treatment, the treated tumor was two thirds smaller compared to the control tumor.. There were indications suggesting that the malfunctioning clock contributed to rapid tumor growth, but this had never been demonstrated. Thanks to the use of a chemical or a thermic treatment, we succeeded in repairing these cells clock and ...
Further clues into the regulation of circadian clocks are the subject of two reports. In plants and insects, cryptochromes (CRYs) are activated by light, and in the fruit fly Drosophila, CRY blocks the negative feedback action of the PER-TIM complex. Griffin et al. show that CRY1 and CRY2 play a central role in the mammal clock, but in a light-independent fashion--they appear to regulate transcriptional cycling of Per1 by contacting both the activator and its feedback inhibitors. In Drosophila, three of the critical clock genes, period (per), timeless (tim), and Drosophila Clock (dClk), are expressed rhythmically. In their study of the cycling of dClk, Glossop et al. have found that the molecular clock in Drosophila is composed of two interlocked negative feedback loops--the per-tim loop, which is activated by the dCLK and CYCLE proteins and repressed by PER-TIM, and the dClk loop, in which these proteins exert the opposite effect.. Glossop, N.R.J., Lyons, L.C., and Hardin. P.E. (1999) ...
Both epidemiological and clinical data suggest circadian involvement in the predisposition, etiology, and progression of immune-related morbidities, such as cancer and autoimmune diseases (37, 38). Inflammatory diseases, in particular, exhibit strong time-of-day symptoms. For example, rheumatoid arthritis has a strong diurnal variation in disease expression, which is accompanied by fluctuations in circulating IL-6 concentration (39). LPS-induced endotoxin shock displays temporal dependency (40), and circadian disruption mimicking jet lag can greatly magnify LPS response (41). According to recent evidence, components of the circadian clock regulate the expression of innate immune molecules, such as proinflammatory cytokines (42) and pattern recognition receptors (14). Rev-erbα is a key clock gene that controls inflammatory cytokine genes, including Il6, in macrophages, indicating that it negatively regulates the inflammatory responses in macrophages (11). In the current study, we found that ...
As a matter of fact, the notion of an internal clock as the sole timing element does not reflect the complexity of the real circumstances. The daily behaviour of living organisms is a combination of immediate responses to changes in the environment and processes controlled by the circadian clock, says Helfrich-Förster. These two protagonists interact to help organisms adjust to their environment in an optimal way. For example, an animal whose eyes are not adapted to darkness will stop its movements after nightfall. And ideally its circadian clock will make the animal stop its activities before it is dark the next day.. The researchers studied the mechanisms and protagonists involved in these complex processes and the way they interact using the example of the fruit fly. The study looked at healthy flies, clockless flies, eyeless flies and flies lacking other timing-related switches. During the laboratory experiments they were exposed to different light conditions: simulated dusk, almost ...
Our results demonstrate that mammalian alternative splicing is regulated by both the circadian clock and feeding. Regulation by such oscillating physiological processes adds a novel temporal dimension to the regulation of alternative splicing, distinct from that involved in both acute and chronic responses to the environment. Circadian regulation of alternative splicing occurred in a tissue-dependent manner and, similarly to circadian mRNA abundance, we anticipate that the circadian regulation of alternative splicing will be important to tissue identity and function. Moreover, the circadian clock frequently modulates physiological systems so that they respond differently to acute stimuli at different times of the day. For example, mice display circadian variation in the ability to consolidate memories in response to hippocampal-dependent fear conditioning, responding less well when conditioned during the subjective night [45]. Furthermore, the susceptibility of mice to Escherichia coli ...
Intracellular circadian clocks, composed of clock genes that act in transcription-translation feedback loops, drive global rhythmic expression of the mammalian transcriptome and allow an organism to anticipate to the momentum of the day. Using a novel clock-perturbing peptide, we established a pivotal role for casein kinase (CK)-2-mediated circadian BMAL1-Ser90 phosphorylation (BMAL1-P) in regulating central and peripheral core clocks. Subsequent analysis of the underlying mechanism showed a novel role of CRY as a repressor for protein kinase. Co-immunoprecipitation experiments and real-time monitoring of protein-protein interactions revealed that CRY-mediated periodic binding of CK2β to BMAL1 inhibits BMAL1-Ser90 phosphorylation by CK2α. The FAD binding domain of CRY1, two C-terminal BMAL1 domains, and particularly BMAL1-Lys537 acetylation/deacetylation by CLOCK/SIRT1, were shown to be critical for CRY-mediated BMAL1-CK2β binding. Reciprocally, BMAL1-Ser90 phosphorylation is prerequisite for ...
Structural biologists have made important progress towards better understanding the functioning of the circadian clock. The circadian or inner clock coordinates the sleep-wake rhythm and many other body processes that regulate, ...
In the classical view of circadian clock organization, the daily rhythms of most organisms were thought to be regulated by a central, master pacemaker, usually located within neural structures of the animal. However, with the results of experiments performed in zebrafish, mammalian cell lines and, more recently, mammalian tissues, this view has changed to one where clock organization is now seen as being highly decentralized. It is clear that clocks exist in the peripheral tissues of animals as diverse as Drosophila, zebrafish and mammals. In the case of Drosophila and zebrafish, these tissues are also directly light-responsive. This light sensitivity and direct clock entrainability is also true for zebrafish cell lines and early-stage embryos. Using luminescent reporter cell lines containing clock gene promoters driving the expression of luciferase and single-cell imaging techniques, we have been able to show how each cell responds rapidly to a single light pulse by being shifted to a common ...
This weeks GARNet research roundup again features papers on a variety of topics. First is work from the University of Leeds that investigates the physical properties of callose:cellulose hydrogels and the implication for cell wall formation. Second is work from the University of York that assesses the role of the HSP90.2 protein in control of the circadian clock. The third paper features GARNet committee member Sarah McKim and looks at the genetic control of petal number whilst the next paper from the Universities of Warwick and Glasgow includes a proteomic analysis of different types of secretory vesicles.. The next two papers look at different aspects of hormone signaling. Firstly Alistair Hetherington from the University of Bristol is a co-author on a study that looks at the role of the BIG protein whilst Simon Turners lab in Manchester investigates the role of ABA in xylem fibre formation.. The penultimate paper includes Lindsey Turnbull from the University of Oxford and looks at the ...
Circadian rhythms of cell and organismal physiology are controlled by an autoregulatory transcription-translation feedback loop that regulates the expression of rhythmic genes in a tissue-specific manner. Recent studies have suggested that components of the circadian pacemaker, such as the Clock and …
In this paper, we present the mathematical details underlying both an approach to the flexibility of regulatory networks and an analytical characterization of evolutionary goals of circadian clock networks. A fundamental problem in cellular regulation is to understand the relation between the form o …
Diurnal patterns of gene transcription are often conferred by complex interactions between circadian clock control and acute responses to environmental cues. Arabidopsis thaliana GIGANTEA (GI) contributes to photoperiodic flowering, circadian clock control, and photoreceptor signaling, and its transcription is regulated by the circadian clock and light. We used phylogenetic shadowing to identify three evolutionarily constrained regions (conserved regulatory modules [CRMs]) within the GI promoter and show that CRM2 is sufficient to confer a similar transcriptional pattern as the full-length promoter. Dissection of CRM2 showed that one subfragment (CRM2-A) contributes light inducibility, while another (CRM2-B) exhibits a diurnal response. Mutational analysis showed that three ABA RESPONSE ELEMENT LIKE (ABREL) motifs in CRM2-A and three EVENING ELEMENTs (EEs) in CRM2-B are essential in combination to confer a high amplitude diurnal pattern of expression. Genome-wide analysis identified ...
The ubiquitin ligases CUL-3 and SLMB collaborate to regulate the Drosophila circadian clock by controlling TIMELESS oscillations.
...The circadian clocks that control and influence dozens of basic biolog...,Snooze,button,on,biological,clocks,improves,cell,adaptability,biological,biology news articles,biology news today,latest biology news,current biology news,biology newsletters
Sundowning or sundown syndrome causes a sudden worsening of confusion, agitation, and aggression in patients with Alzheimers disease and dementia, which was found to be governed by the bodys internal biological clock.
Circadian clocks synchronize cellular metabolism to the diurnal light cycle. In humans, our biological clocks impact many aspects of our physiology, including s...
BMAL1 can form heterodimers with either CLOCK or NPAS2, which act redundantly but show different tissue specificity. The BMAL1:CLOCK and BMAL1:NPAS2 heterodimers activate a set of genes that possess E-box elements (consensus CACGTG) in their promoters. This confers circadian expression on the genes. The PER genes (PER1, PER2, PER3) and CRY genes (CRY1, CRY2) are among those activated by BMAL1:CLOCK and BMAL1:NPAS2. PER and CRY mRNA accumulates during the morning and the proteins accumulate during the afternoon. PER and CRY proteins form complexes in the cytosol and these are bound by either CSNK1D or CSNK1E kinases which phosphorylate PER and CRY. The phosphorylated PER:CRY:kinase complex is translocated into the nucleus due to the nuclear localization signal of PER and CRY. Within the nucleus the PER:CRY complexes bind BMAL1:CLOCK and BMAL1:NPAS2, inhibiting their transactivation activity and their phosphorylation. This reduces expression of the target genes of BMAL1:CLOCK and BMAL1:NPAS2 ...
I originally published this on June 26th, 2006. The persistence of circadian rhythmicity during long bouts of hibernation in mammals has been a somewhat controversial topic in the literature. While some studies suggest that circadian clock is active during hibernation, other studies dispute this. Apparently, the truth is somewhere in-between - it differs between species:…
ARM] 4550/1: sched_clock on PXA should cope with run time clock rate selection The previous implementation was relying on compile time optimizations based on a constant clock rate. However, support for different PXA flavors in the same kernel binary requires that the clock be selected at run time, so here it is. Lets move this code to a more appropriate location while at it. Signed-off-by: Nicolas Pitre ,[EMAIL PROTECTED], Signed-off-by: Russell King ,[EMAIL PROTECTED], --- arch/arm/mach-pxa/generic.c , 62 ------------------------------------------- arch/arm/mach-pxa/time.c , 39 +++++++++++++++++++++++++++ 2 files changed, 39 insertions(+), 62 deletions(-) diff --git a/arch/arm/mach-pxa/generic.c b/arch/arm/mach-pxa/generic.c index 5510f6f..9d6a2c0 100644 --- a/arch/arm/mach-pxa/generic.c +++ b/arch/arm/mach-pxa/generic.c @@ -25,10 +25,6 @@ #include ,linux/pm.h, #include ,linux/string.h, -#include ,linux/sched.h, -#include ,asm/cnt32_to_63.h, -#include ,asm/div64.h, - #include ,asm/hardware.h, ...
Science & Biotech Career Center - Free Listing of Postdoc, Faculty Positions, Academic and Industrial Jobs
Midkine expression is regulated by the circadian clock in the retina of the zebrafish - Volume 26 Issue 5-6 - ANDA-ALEXANDRA CALINESCU, PAMELA A. RAYMOND, PETER F. HITCHCOCK
DICER1 activity, was decreased. Importantly, single channel analysis in amphibian renal cells exhibited a dramatic decrease in the number of patches with observable ENaC current following CK1/ inhibition. The present study shows for the first time that CK1/ inhibition and impaired Per1 nuclear access results in decreased ENaC expression and ENaC activity, providing further support for direct control of ENaC by the circadian clock. for 10 min. Cells were resuspended in sucrose (10 mM Tris, 1 mM EDTA, 50 mM sucrose) and homogenized. The same level of sucrose (10 mM Tris, 1 mM EDTA, 250 mM sucrose) was added, accompanied by extra homogenization. Nuclei had been pelleted at 1,000 for 10 min and discarded. Organelles had been pelleted at 10,000 for 20 min and discarded. Supernatants had been centrifuged at >60,000 for 18 h. Membrane protein pellets were resuspended in 50 l of phosphatase and sucrose and protease inhibitors. Protein concentrations had been after that quantified by BCA assay (Pierce). ...
In 2012, a group led by Thomas P. Burris, then at Scripps Research Institute Florida and now at St. Louis University, designed and synthesized SR9009 and SR9011 to activate REV-ERB receptors (Nature 2012, DOI: 10.1038/nature11030). They showed that the compounds had metabolic effects-obese mice treated with the compounds lost weight. Based on previously observed associations between the circadian clock and cancer, Sulli, Panda, and coworkers speculated that the compounds might affect cancer cell viability as well. Panda notes that patents for the compounds are owned by Scripps and that there is no immediate commercialization plan from Salk.. ...
Circadian clocks keep us, and our plants, reasonably attuned to the cycle of days and nights. Analyses of the molecules in the plant Arabidopsis that achieve this steady coordination have led to interlocking networks of logic and feedback loops of gene regulation. Pruneda-Paz et al. (see the Perspective by McClung) have now used a targeted genomics approach with yeast to add another molecule to the game: the transcription factor CHE. CHE binds to already known clock components of Arabidopsis and forms a linkage that was predicted but not yet closed, namely, bringing together a known clock component, TOC1, with its expected target gene, CCA1.. J. L. Pruneda-Paz, G. Breton, A. Para, S. A. Kay, A functional genomics approach reveals CHE as a component of the Arabidopsis circadian clock. Science 323, 1481-1485 (2009). [Abstract] [Full Text]. C. R. McClung, Linking the loops. Science 323, 1440-1441 (2009). [Summary] [Full Text]. ...
King DP, Zhao Y, Sangoram AM, Wilsbacher LD, Tanaka M, Antoch MP, Steeves TD, Vitaterna MH, Kornhauser JM, Lowrey PL, Turek FW, Takahashi JS. Cell. 1997;89(4):641-53. Genetic mapping and sequencing in mice confirmed the identification of the mammalian gene, clock, involved in the circadian system. A comparison of the nucleotide sequence of the wildtype gene with…
Circadian clocks are not only found in discrete areas of the brain, but are found in virtually every organ in our bodies, including the heart, lungs and immune system. Disruptions in circadian clocks, or chronopathology, may underlie various forms of cardiovascular, pulmonary, and metabolic disorders. Over the past two decades, molecular geneticists have cracked the clock to reveal its core biochemical mechanisms evident in organisms from fruit flies to humans. These mechanistic insights have led to the discovery of links between clock function and an ever-expanding array of prevalent diseases, including heart, lung, metabolic and sleep disorders. Yet the prevalence of circadian disruption in these patient populations is unclear because current tests are not easily applied in clinical settings or have yet to be developed. Perhaps the major limitation of these techniques is the need for serial sampling over extended periods of at least 24 hours and in some cases longer. The development of an ...
If you are a society or association member and require assistance with obtaining online access instructions please contact our Journal Customer Services team ...
The Genetics Society of America (GSA), founded in 1931, is the professional membership organization for scientific researchers and educators in the field of genetics. Our members work to advance knowledge in the basic mechanisms of inheritance, from the molecular to the population level.. Online ISSN: 2160-1836. ...
Activator-repressor systems have been shown to be capable of oscillations and are therefore an important clock motif in the field of Synthetic and Systems Biology. In this paper, we propose a method to regulate oscillatory behavior in such systems by the addition of DNA binding sites for the proteins involved in the clock network. We show that the retroactivity effect caused by this addition can effectively change the relative timescales among the protein dynamics and impact the behavior of the clock. We also employ root locus analysis to obtain a graphical interpretation of the results ...
Individual plant cells have a genetic circuit, the circadian clock, that times key processes to the day-night cycle. These clocks are aligned to the day-night cycle by multiple ...
Drosophila fruit flies are so named after the Latin for dew loving because they are more active at dawn and dusk. This strong sense of circadian rhythm (the 24 hour time cycle) is generated by a clock that ticks in the brain of all animals including humans.. The flys clock consists of about one hundred neurons in its 100,000-neuron brain, which can fit on a pin head. Inside each clock neuron is a molecular clock that consists of clock genes, which switch each other on and off every night and day.. Writing in the journal PNAS today, a team of researchers, led by Dr Edgar Buhl and Dr James Hodge from the University of Bristol in collaboration with Professor Ralf Stanewskys group at UCL, explain how they identified three novel proteins that act together on the surface of clock neurons to make the clock light responsive.. To be useful for an organism, circadian clocks need to be synchronized (or reset) to the natural environment cycles of light and temperature, much like you need to reset ...
Circadian clocks have become popular systems for studying the relationship between gene-protein dynamics and phenotype. The molecular machinery underlying these networks has been relatively well characterized, and this has led to great interest in developing predictive computational models of the clock. Such models are usually formulated as sets of DEs. The high level of biochemical detail afforded by this approach has allowed DE models to successfully address a range of issues regarding the functional relationship between the architecture of the clock and circadian homeostasis. One homeostatic mechanism that has been comprehensively investigated from a theoretical perspective is temperature compensation. By assuming that certain subsets of a circuits kinetic parameters are temperature-dependent, temperature has been incorporated into a number of circadian DE models, ranging from minimal circuits built on the Goodwin oscillator [15,23,58] to more detailed formulations that explicitly model the ...
The 24-hour internal clock controls many aspects of human behavior and physiology, including sleep, blood pressure, and metabolism. Disruption in circadian
The Buccaneers announced this morning that theyll take a look at defensive end DaQuan Bowers in practice this week, starting the clock on a remarkable recovery from what was thought to be a season-ending injury.
According to the Centers for Disease Control and Prevention (CDC), around 30 percent of the adult population reports that they suffer from joint discomfort. While the reasons people have it may vary, there is now a new product on the market that will help them take on their joint problems, as well as turn back the clock on aging, so they not only feel younger, but look younger, too.. Everyone looks for the fountain of youth so they can improve their mobility as well as reduce wrinkles, explained Asma Ishaq, president of Jusuru International, a company that develops nutraceuticals and dietary supplements. We have created exactly what people have been looking for, and its worked time after time in clinical studies.. The new super ingredient scientifically developed by the company is called Liquid BioCell™, which is a naturally occurring matrix of hydrolyzed collagen, hyaluronic acid (HA), and chondroitin sulfate, all key components of healthy joints and supple skin. The patented formula has ...
Free Configurable Desktop Clock Download,Configurable Desktop Clock 1.1 is Clock Utility to Display Configurable Clock on Desktop.
TY - JOUR. T1 - Inhibition of protein kinase A phase delays the mammalian circadian clock. AU - Lee, Jennifer M.. AU - Schak, Kathryn M.. AU - Harrington, Mary E.. PY - 1999/7/24. Y1 - 1999/7/24. N2 - The suprachiasmatic nuclei (SCN) contain the mammalian circadian clock whose rhythm of firing rate can be recorded in vitro for several days. Application of a protein kinase A (PKA) inhibitor onto the SCN at Zeitgeber time (ZT) 10 on the first day in vitro phase delayed the rhythm of firing rate expressed by SCN neurons on the subsequent day in vitro. Application of the inhibitor (Rp-cAMPS) at other circadian phases did not phase shift the rhythm. These results suggest that during approximately 1 h in the late subjective day the presence and activity of PKA plays a role in setting the phase of the mammalian circadian clock.. AB - The suprachiasmatic nuclei (SCN) contain the mammalian circadian clock whose rhythm of firing rate can be recorded in vitro for several days. Application of a protein ...
Circadian clocks are fundamental properties of all eukaryotic organisms and at least some prokaryotic organisms. Recent studies in our laboratory have shown that the gastrointestinal system contains a circadian clock that controls many, if not all, aspects of gastrointestinal function. We now report that at least one species of intestinal bacteria, Enterobacter aerogenes, responds to the pineal and gastrointestinal hormone melatonin by an increase in swarming activity. This swarming behavior is expressed rhythmically, with a period of approximately 24 hrs. Transformation of E. aerogenes to express luciferase with a MotA promoter reveals circadian patterns of bioluminescence that are synchronized by melatonin and whose periods are temperature compensated from 26°C to 40°C. Bioinformatics suggest similarities between the E. aerogenes and cyanobacterial clocks, suggesting the circadian clock may have evolved very early in the evolution of life. They also point to a coordination of host circadian ...
Circadian rhythms in a wide variety of cellular and metabolic processes are well documented in many organisms. An important step in understanding the molecular basis of the circadian clock is the characterization of clock-controlled genes. mRNA accumulation of two catalase genes, CAT2 and CAT3, in the higher plant, Arabidopsis thaliana, responds to organ-specific, developmental, temperature, and light signals, as well as to the circadian clock. Most strikingly, the circadian phases of maximal mRNA abundance for the two CAT genes are distinct, with CAT2 mRNA most abundant in the morning and CAT3 mRNA peaking in the evening. Thus, elements of the output pathways emanating from the circadian clock to regulate CAT2 and CAT3 expression must differ. The CAT3 genomic locus was isolated and characterized. Transgenic Arabidopsis containing CAT3-uidA fusions have been generated as a first step towards the identification of cellular components required for the circadian regulation of CAT3 gene. Elements ...
A programmable clock generator circuit receives control signals and a global clock and generates a pulsed data clock and a scan clock in response to gating signals. The clock generator has data clock and scan clock feed-forward paths and a single feedback path. Delay control signals program delay elements in the feedback path and logic gates reshape and generate a feedback clock signal. The global clock and the feedback clock signal are combined to generates a pulsed local clock signal. A scan clock feed-forward circuit receives the local clock and generates the scan clock. A data clock feed-forward circuit receives the local clock and generates the data clock with a logic controlled delay relative to the local clock signal. The feedback clock is generated with controlled delay thereby modifying the pulse width of the data and scan clocks independent of the controlled delay of the data clock feed-forward path.
Fast shipping specials nohassle returns on. Come in a custom record clock movement with any. Independant component wall clocks, wall clock parts suppliers brings you a leading supplier of wall clock components products united states canada to search enter a few every purchase supports independent analog clock standard wall clock movements quick and anniversary clocks from designers such as a wall mantel clock components time systems after years franklin clocks today. Audio inwall kit ht2002whv1 at. Clocks component mechanism diy repair but they generally belong to set up wall clock wall and battery or call us at clockworks or call. Ebay. Wall lights at guaranteed low prices. Modern wall clocks large, sale every day with one now. Wall and desk clocks and manufacturing of contemporary modern wall clocks are in our large wall clock styles antique wall and wallmounted light fixtures free shipping on the newest designs for every day at save time the largest selection of wall clocks are bolder and ...
Transcriptional activator which forms a core component of the circadian clock. The circadian clock, an internal time-keeping system, regulates various physiological processes through the generation of approximately 24 hour circadian rhythms in gene expression, which are translated into rhythms in metabolism and behavior. It is derived from the Latin roots circa (about) and diem (day) and acts as an important regulator of a wide array of physiological functions including metabolism, sleep, body temperature, blood pressure, endocrine, immune, cardiovascular, and renal function. Consists of two major components: the central clock, residing in the suprachiasmatic nucleus (SCN) of the brain, and the peripheral clocks that are present in nearly every tissue and organ system. Both the central and peripheral clocks can be reset by environmental cues, also known as Zeitgebers (German for timegivers). The predominant Zeitgeber for the central clock is light, which is sensed by retina and signals directly to
The circadian rhythm, also called circadian clock or just inner clock, is the endogenous capability of an organism to retain a 24 h rhythm without being exposed to environmental stimuli that indicate the time of day. Animals, plants and even fungi generate a circadian rhythm and plays a major role in daily live. For humans it is the mechanism to regulate sleep and wakefulness. Interestingly, during the first half year of life, as infants, humans do not have a working circadian rhythm, which explains why babies have an erratic sleeping pattern. They wake up in the middle of the night and are wide awake, much to the suffering of the parents. At around three to six months of age, the circadian clock starts to get established, and babies begin to sleep at night and are awake during the day. How are sleep and wakefulness regulated?. There are two mechanisms or systems that take care of sleep and wakefulness. This first is the sleep and wake homoeostasis, which is a balance-system of sleep and ...
Circadian rhythm is an internal biological clock, which enables to sustain an approximately 24-hour rhythm in the absence of environmental cues. In mammals, the circadian clock mechanism consists of cell-autonomous transcription-translation feedback loops that drive rhythmic, 24-hour expression patterns of core clock components. The first negative feedback loop is a rhythmic transcription of period genes (PER1, PER2, and PER3) and chryptochrome genes (CRY1 and CRY2). PER and CRY proteins form a heterodimer, which acts on the CLOCK/BMAL1 heterodimer to repress its own transcription. PER and CRY proteins are phosphorylated by casein kinase epsilon (CKIepsilon), which leads to degradation and restarting of the cycle. The second loop is a positive feedback loop driven by the CLOCK/BMAL1 heterodimer, which initiates transcription of target genes containing E-box cis-regulatory enhancer sequences ...
The rhythmic genes we have identified under LD and DD conditions display bone fide rhythmic expression. The inclusion of seven known rhythmic genes (per, tim, vri, Clk, Dreg-2, cry, and takeout) in the set of 72 diurnally oscillating genes and four (per, tim, vri, and Clk) in the set of 22 circadianly oscillating genes provides confidence that the autocorrelation method we applied identifies rhythmic gene expression with fidelity.. The true number of circadianly regulated genes in Drosophila can only be estimated; the accuracy of any estimate depends on both methodological constraints and assumptions used in the data analysis. Our estimates of 72-200 robustly oscillating genes in LD 12:12 and a minimum of 22 genes in DD likely underestimate the true number of oscillating genes in the fly head. First, by necessity the choices of A0 minima were determined empirically. In the absence of true positive controls (i.e., rhythmically spiked foreign, polyadenylated message), we relied on the reproducible ...
A single 2 hour bright light pulse at night combined with a 4 hour delay of the sleep/dark episode delayed the human circadian clock an average of ~1.5 hours. We also observed individual differences in the magnitude of the phase delay, from virtually no delay to up to 2 hours. These findings more clearly delineate the rate at which the circadian clock can be delayed in a practical protocol that could be used in the real world. Previous studies utilizing a single bright light pulse ending late at night with subjects waking at their habitual time (sleep episode truncated) have reported phase delays of about 1 hour [24, 25]. Studies in which a single long duration bright light pulse (, 6 hours, up to ~10,000 lux) was paired with 2 days of a large delay (,8 hours) in the sleep/dark episode have reported phase delays of up to 3 hours [9, 12, 27, 28]. Although a 3 hour phase delay from a single day of light treatment is robust, such a large shift in the sleep schedule may not be appealing or feasible ...
Circadian rhythms modulate growth and development in all organisms through interlocking transcriptional-translational feedback loops. The transcriptional loop involves chromatin modifications of central circadian oscillators in mammals and plants. However, the molecular basis for rhythmic epigenetic modifications and circadian regulation is poorly understood. Here we report a feedback relationship between diurnal regulation of circadian clock genes and histone modifications in Arabidopsis. On one hand, the circadian oscillators CCA1 and LHY regulate diurnal expression of genes coding for the eraser (JMJ14) directly and writer (SDG2) indirectly for H3K4me3 modification, leading to rhythmic H3K4me3 changes in target genes. On the other hand, expression of circadian oscillator genes including CCA1 and LHY is associated with H3K4me3 levels and decreased in the sdg2 mutant but increased in the jmj14 mutant. At the genome-wide level, diurnal rhythms of H3K4me3 and another histone mark H3K9ac are associated
Epigenetic Modulation of Circadian Rhythms: Bmal1 Gene Regulation. By Tatsunosuke Tomita and Yoshiaki Onishi. Circadian rhythms that function in behaviour and physiology have adaptive significance for living organisms from bacteria to humans and reflect the presence of a biological clock. The engine of circadian rhythms is a transcription-translation feedback loop that is fine-tuned by epigenetic regulation in higher eukaryotes. We elucidated the chromatin structure of the Bmal1 gene, a critical component of the mammalian clock system, and have continued to investigate transcriptional regulation including DNA methylation. Various ailments including metabolic diseases can disrupt circadian rhythms, and many human diseases are associated with altered DNA methylation. Therefore, regulated circadian rhythms are important for human health. Here, we summarise the importance of epigenetic clock gene regulation, including DNA methylation of the Bmal1 gene, from the viewpoint of relationships to ...
Many organisms have ≈24-h rhythms in metabolism, physiology, and behavior that are driven by cell autonomous circadian pacemakers (1). These circadian rhythms allow organisms to coordinate a myriad of physiological processes with the changing environment. In mammals, the circadian pacemaker is composed of interlocked transcription-translation feedback loops: the primary loop is composed of the basic helix-loop-helix transcription factors CLOCK and BMAL1, which drive transcription of the Period (Per1, Per2) and Cryptochrome (Cry1, Cry2) genes (1, 2). PER and CRY proteins form the negative limb of the feedback loop by inhibiting their own CLOCK:BMAL1-induced transcription; turnover of PER and CRY allows the cycle to begin anew. The interlocked loop consists of REV-ERB-α and RORα, which repress and activate the Bmal1 gene, thereby modulating its function (3, 4). Mutation or deletion of Clock (5), Bmal1 (6), Per1/2 genes (7, 8), or Cry1/2 (9, 10) genes results in behavioral arrhythmicity and ...
Apparatus and method support the synchronization and calibration of a plurality of clocks in a medical device system that may provide treatment to a patient with a nervous system disorder. The plurality of clocks, which may be located at different components of the medical device system, comprises a first clock and a second clock. The second clock may be synchronized to a first clock by disabling a run mode operation and setting the second clock to a selected time. When a reference time of the first clock approximately equals the selected time, the second clock enables the run mode operation. Additionally, a drift time that is indicative of a time difference between the first clock and the second clock is determined. If the drift time is greater than a predetermined amount, an indication to resynchronize the first and second clocks is provided.
A method for routing clock signals in an integrated circuit provides a hierarchical routing scheme in which the lowest level clock buffers are first placed row by row in preallocated locations and routed to the input pins of standard cells receiving the output clock signals of these clock buffers. Under the method, the number of clock buffers to be placed in each row is computed according to estimates of their load capacitances and expected wiring lengths within a window. The output buffers of the same clock signal are gridded or strapped together to minimize clock skew. A second level of clock buffers are then assigned to drive the lowest level buffers. The hierarchy can be extended to any number of higher levels, until clock signals are routed for the entire integrated circuit. The higher level clock signals can also be strapped or gridded to minimize clock skew.
Our possessions should tell people who we are. Let the items that sit on your desk let people who come into your office know what youre about. If you want a clock that lets everyone know youre a science super geek, then the Model AWK-105 Analog Voltmeter Clock is for you.. This clock looks like an analog voltmeter. Its right there in the name. In fact, at first glance, most people probably wouldnt even consider it was a clock. A clock it is though! It reads hours and minutes but on two separate faces. The hours are on the left side and the minutes are on the right side. From there on, its just like a normal clock.. This clock reads like any normal 12 hour clock, even though it looks just a bit different. It will give you down to the minute time and stay true unless theres a power outage. This clock is manually set so you can look forward to visiting it twice a year for Daylight Savings Time. The Model AWK-105 Analog Voltmeter Clock is $139.. ...
A 2/N mode dock generator that generates bus clock signals through the use of bus clock enable signals selecting bus clock pulses that are in phase and out of phase with a core clock signal. The clock generator maintains synchronization between the bus clock signal and the core clock signal so that they are always in a predetermined phase relationship.
Purpose: CLOCK and NPAS2, homologous circadian clock proteins, are expressed in the mammalian retina. However, their specific roles in retinal gene regulation or function have not been elucidated. This study was conducted to determine whether NPAS2 and CLOCK are co-expressed in retinal neurons and their effects on retinal gene expression and function.. Methods: Studies were performed using C57BL/6 wildtype (WT), Clock-/-, and Npas2-/- mice. Laser capture microdissection and quantitative real-time PCR were performed to isolate the ganglion cell layers (GCL) at five time points for transcription expression analyses for Npas2, Clock, and Adcy1. Luciferase reporter assay in NG108-15 cells was conducted to determine whether CLOCK/BMAL1 and/or NPAS2/BMAL1 heterodimers could activate the Adcy1 promoter. Contrast sensitivity was measured using optokinetic tracking at mid-day and mid-night time points, and scotopic and photopic electroretinograms (ERG) were recorded to measure retinal responses to ...
The circadian genetic machinery is so well conserved in the evolution that the study of Drosophila provides a cheap alternative to knockout experiments in rodents. Orthologs have been identified in mammals for most of the Drosophila circadian clock genes. In insects though, unlike in mammals, CRY1 function is light-dependent. Even cyanobacteria have a circadian genetic clock that can be reconstituted in vitro for detailed quantitative analysis and comparative simulations. One of the conclusions coming from studying cyanobacteria is that the TTFL clock may actually be a slave to a master biochemical oscillator called the PTO (post-translational oscillator) (Qin et al. 2010[1]). The initial suggestion on the role of biochemical oscillators came from the persistence of the circadian rhythm in conditions of inhibited transcription and translation (Iwasaki et al. 2005[2]). Beyond their circadian roles, the genes are also involved in other functions. Interestingly, cryptochromes have been shown to be ...
For each species, we generated a phase-ordered microarray time series covering one segmentation clock oscillation. For each embryo of each species, the posterior half of the right-hand side presomitic mesoderm (PSM) was surgically removed, leaving the rest of the embryo intact. RNA was then extracted from the dissected piece and amplified before hybridization of each sample individually on an Affymetrix GeneChip array (Fig. 1A). The remaining part of the dissected embryo was used to visualize the cyclic traveling wave, which propagates anteriorly along the PSM during one cycle of the segmentation clock. These dynamic stripes were detected by in situ hybridization (ISH) with the known cyclic genes Lfng for mouse and chick (Aulehla and Johnson, 1999; McGrew et al., 1998) and her7 (Oates and Ho, 2002) for zebrafish. Samples were then ordered chronologically a posteriori, within an oscillatory cycle, based on the anteroposterior position of the expression stripe along the PSM (Fig. 1B-D). Twenty-two ...
Drosophila melanogaster locomotor activity responds to different seasonal conditions by thermosensitive regulation of splicing of a 3′ intron in the period mRNA transcript. Here we demonstrate that the control of locomotor patterns by this mechanism is primarily light-dependent at low temperatures. At warmer temperatures, when it is vitally important for the fly to avoid midday desiccation, more stringent regulation of splicing is observed, requiring the light input received through the visual system during the day and the circadian clock at night. During the course of this study, we observed that a mutation in the no-receptor-potential-AP41 (norpAP41 ) gene, which encodes phospholipase-C, generated an extremely high level of 3′ splicing. This cannot be explained simply by the mutations effect on the visual pathway and suggests that norpAP41 is directly involved in thermosensitivity ...
The 527-02 Clock Slicer is the most flexible way to generate a CMOS output clock from a PECL input clock with zero skew. The user can easily configure the device to produce nearly any output clock that is multiplied or divided from the input clock. The part supports non-integer multiplications and divisions. A SYNC pulse indicates when the rising clock edges are aligned with zero skew. Using Phase-Locked Loop (PLL) techniques, the device accepts an input clock up to 200 MHz and produces an output clock up to 160 MHz. The 527-02 aligns rising edges on PECLIN with FBIN at a ratio determined by the reference and feedback dividers. For a PECL input and output clock with zero delay, use the 527-04. For a CMOS input and PECL output with zero delay, use the 527-03. ...
The 527-01 Clock Slicer is the most flexible way to generate an output clock from an input clock with zero skew. The user can easily configure the device to produce nearly any output clock that is multiplied or divided from the input clock. The part supports non-integer multiplications and divisions. A SYNC pulse indicates when the rising clock edges are aligned with zero skew. Using Phase-Locked Loop (PLL) techniques, the device accepts an input clock up to 200 MHz and produces an output clock up to 160 MHz. The 527-01 aligns rising edges on ICLK and FBIN at a ratio determined by the reference and feedback dividers. For configurable clocks that do not require zero delay, use the 525.. ...
A method of calibrating a first clock signal using a second clock signal and a plurality of calibration periods may include generating incremented counter values at a counter responsive to edges of the second clock signal. For at least two of the plurality of calibration periods, an initial incremented counter value from the counter may be stored in memory at an initial edge of the first clock signal for the respective calibration period, a final incremented counter value may be stored in memory at a final edge of the clock signal for the respective calibration period, and the at least two of the plurality of calibration periods may be overlapping with different initial and final edges of the first clock signal. For each of the plurality of calibration periods, a number of edges of the second clock signal occurring during the respective calibration period may be determined using the initial and final incremented counter values stored in memory. A relationship between the first and second clock signals
TY - JOUR. T1 - The eIF2α Kinase GCN2 Modulates Period and Rhythmicity of the Circadian Clock by Translational Control of Atf4. AU - Pathak, Salil Saurav. AU - Liu, Dong. AU - Li, Tianbao. AU - de Zavalia, Nuria. AU - Zhu, Lei. AU - Li, Jin. AU - Karthikeyan, Ramanujam. AU - Alain, Tommy. AU - Liu, Andrew C.. AU - Storch, Kai Florian. AU - Kaufman, Randal J.. AU - Jin, Victor X.. AU - Amir, Shimon. AU - Sonenberg, Nahum. AU - Cao, Ruifeng. N1 - Funding Information: We are grateful to David Ron at University of Cambridge for providing the Gcn2?/? 129SvEv mice and Tim M. Townes at the University of Alabama at Birmingham for providing the Atf4+/? mice. We thank Andrew Chapman and Isaac Edery for critical reading of the manuscript. This study was supported by a Faculty Start-Up Grant from the University of Minnesota Medical School and a grant from Whiteside Institute for Clinical Research to R.C. a grant from the Canadian Institutes of Health Research (CIHR) to N.S. (MOP7214), a grant from CIHR to ...
All cells possess a molecular circadian ?clock? thought to coordinate various aspects of the physiology and behavior of an animal with the light/dark cycle of the external world. Light is the principle cue entraining molecular clocks via the suprachiasmatic nucleus of the brain. Recent evidence however, has also implicated food-borne signals as external stimuli capable of resetting clocks in the periphery. The aim of this study was to investigate the impact of aberrant feeding on circadian energy metabolism in the rat by feeding a high fat diet and restricting feeding to the daylight hours. Here we show that rats on the daylight feeding and high-fat feeding schedules displayed various differences in metabolism including hormone and metabolite levels and gene and protein expression. In the liver the circadian expression pattern of molecular clock genes was completely reversed in response to the new feeding schedule. In contrast, circadian gene expression in muscle remained similar to an animal feeding ad
Tumor cells use the unfolded protein response to alter circadian rhythm, which contributes to more tumor growth, Hollings Cancer Center researchers at the Medical University of South Carolina (MUSC) find. A key part of the circadian clock opposes this process, according to a paper published online Dec. 11 in Nature Cell Biology.
NIH Funding Opportunities and Notices in the NIH Guide for Grants and Contracts: Sleep disorders and circadian clock disruption in Alzheimers disease and other dementias of aging (R01 Clinical Trial Not Allowed) PAR-18-497. NIA
A video sub-system features reduced power consumption by periodically disabling the video controller clocks used for transferring pixel data to a screen. The video clocks are pulsed only when pixel data is being transferred to the screen, during the time that a horizontal line of pixels is being scanned on the screen. The video clocks are not pulsed during the horizontal and vertical blanking periods, when the electron beam in a cathode-ray-tube is being re-traced. The video clocks are also not pulsed during a recovery period for a flat-panel screen. A video memory contains pixel information for the entire screen and is controlled by a memory controller. The memory controller uses a memory clock to transfer all or part of a horizontal line of pixels to a video buffer. The pixel data is then read out of the video buffer to the screen in a serial fashion, synchronized to the video clock. Host data may be written to a host buffer using a bus clock from the host, and then written to the video memory using
Dartmouth researchers have found evidence of two circadian clocks working within the same tissue of the plant Arabidopsis thaliana; posted 05/07/03 by Sue Knapp
Researchers discovered a link between circadian clock disturbances in pancreatic cells and type 2 diabetes (T2D), according a study published in Proceedings of the National Academy of Sciences.
Martí Ruiz MC, Hubbard KE, Gardner MJ, Jung HJ, Aubry S, Hotta CT, Mohd-Noh NI, Robertson FC, Hearn TJ, Tsai YC, Dodd AN, Hannah M, Carré IA, Davies JM, Braam J, Webb AAR (2018) Circadian oscillations of cytosolic free calcium regulate the Arabidopsis circadian clock. Nat Plants. 2018 Aug 20. doi: 10.1038/s41477-018-0224-8. This second paper from the labs of Alex Webb and Anthony Dodd also features work from Isabelle Carres and Julia Daviss lab in Warwick and Cambridge respectively. This work led by María Carmen Martí Ruiz, Katharine Hubbard and Michael J. Gardner looks at the how oscillations of cytoplasmic calcium influence the central circadian clock. They show that calcium influences the clock through the activity of the CALMODULIN-LIKE24 (CML24) gene and further genetic analysis links these activities through the action of the central clock gene TIMING OF CAB2 EXPRESSION1 (TOC1). This paper is also a clear lesson in persistence as it was first received by Nature Plants back in May ...
The anticipation of daily transitions like dawn and dusk by a circadian clock provides a fitness advantage in cyanobacteria, plants, fungi, and animals (Dodd et al. 2005; Green et al. 2002; Xu et al. 2011; Yerushalmi et al. 2011). Although the circadian clock comprises a highly interconnected network of transcriptional activators and repressors, this adaptation to a rhythmic environment has been maintained while the expansion of gene families and whole-genome duplication or triplication events have altered the balance between different clock components. With the advent of genome-sequencing platforms, we are now in an ideal position to study the evolutionary trajectory of clock gene families, including gene copy number variation, and the birth and death of new copies. Because of its network properties, the circadian clock constitutes a great model system in which to test the gene balance hypothesis. Indeed, Albert Blakeslee observed already in the early 1920s that plants with three copies of a ...
2. Time Clock Manager Pro 2.1 An employee time clock and a management tool. Its allows user to clock in/clock out. It works with touch screen monitors. Also has reports to show clocked in and clock out times. The application has integrated security and can work with networks... Details - Download Tags: time Clock Software , time , clock , manager , managerment , tool , employee , report , clockin , clockout , calculator , vsisystems , szamody ...
Wall clocks in hospitals large and small, as well as in colleges and universities, along with all major businesses, have a continuing need for wall clocks. It can be especially important to have clocks that keep good time and do not break down, so that hospital workers and office individuals are not disagreeing about whether the quitting time has actually arrived or not.. Even hospital purchasing organizations, procurement divisions of government, businesses and other organizations are always seeking to maintain and improve the systems in place to track time, and wall clocks, not surprisingly, are the clock of choice.. When it comes to accuracy, radio controlled or atomic clocks have gained much favor and general acceptance by major institutions. Many purchase just a few to test them out to ensure they will work well for them. There is also a technology known as an Autoset or Auto Set clock which is generally not an atomic, but does automatically move forward an hour and back an hour on the ...
13h à 14h Le séminaire de David Lubensky (University of Michigan) aura lieu dans lAmphi Urbain, ESPCI, 10 Rue Vauquelin 75005 All plants and (...)
Metabolic activities are regulated by the circadian clock, and disruption of the clock exacerbates metabolic diseases including obesity and diabetes. Transcriptomic studies in metabolic organs suggested that the circadian clock drives the circadian expression of important metabolic genes. Here we show that histone deacetylase 3 (HDAC3) is recruited to the mouse liver genome in a circadian manner. Histone acetylation is inversely related to HDAC3 binding, and this rhythm is lost when HDAC3 is absent. Diurnal recruitment of HDAC3 corresponds to the expression pattern of REV-ERBα, an important component of the circadian clock. REV-ERBα colocalizes with HDAC3 near genes regulating lipid metabolism, and deletion of HDAC3 or Rev-erbα in mouse liver causes hepatic steatosis. Thus, genomic recruitment of HDAC3 by REV-ERBα directs a circadian rhythm of histone acetylation and gene expression required for normal hepatic lipid homeostasis. In addition, we reported that the REV-ERBα paralog, REV-ERBβ also
1. Zheng X, Sehgal A (2012) Speed control: cogs and gears that drive the circadian clock. Trends Neurosci 35: 574-585. doi: 10.1016/j.tins.2012.05.007 22748426. 2. Hardin PE (2011) Molecular genetic analysis of circadian timekeeping in Drosophila. Adv Genet 74: 141-173. doi: 10.1016/B978-0-12-387690-4.00005-2 21924977. 3. Rothenfluh A, Young MW, Saez L (2000) A TIMELESS-independent function for PERIOD proteins in the Drosophila clock. Neuron 26: 505-514. 10839368. 4. Curtin KD, Huang ZJ, Rosbash M (1995) Temporally regulated nuclear entry of the Drosophila period protein contributes to the circadian clock. Neuron 14: 365-372. 7857645. 5. Ko HW, Kim EY, Chiu J, Vanselow JT, Kramer A, et al. (2010) A hierarchical phosphorylation cascade that regulates the timing of PERIOD nuclear entry reveals novel roles for proline-directed kinases and GSK-3beta/SGG in circadian clocks. J Neurosci 30: 12664-12675. doi: 10.1523/JNEUROSCI.1586-10.2010 20861372. 6. Chang DC, Reppert SM (2003) A novel C-terminal ...
The molecular clock of the fruit fly is sensitive to magnetic fields in a manner dependent on blue light and the photopigment cryptochrome.
In modern societies, the risk of developing metabolic disorders such as obesity or type-2 diabetes is associated with the prevalence of psychosocial stress. Therefore, an improved understanding of adaptive stress responses and their underlying molecular mechanisms is of high clinical interest. In response to an acute stressor, animals activate the sympathetic nervous system and the hypothalamus pituitary adrenal (HPA) axis releasing catecholamines and glucocorticoids (GCs) into the circulation. Recent data suggest that stress responses are also regulated by the endogenous circadian clock adapting physiology and behavior to the environmental changes brought about by the Earth s rotation around its axis. Thus, the timing of stress may critically affect adaptive responses to and the pathological effects of repetitive stressor exposure. We have studied the role of different tissue clocks on the regulation of HPA axis activity in mice. We further characterized the impact of predictable social defeat ...
It s always amazing to see something that looks so simple and see it transform into something well thought out and complex. That s exactly what s happening here with the Clock Clock. This is a huge what looks to be four-paneled clock that is actually made up of twenty-four small ones. Each panel is made up of 6 smaller clocks that have very basic faces, which adds a very interesting aesthetic.. Once the time changes, the hands on the panel in which a number is changing will all spin until all the hands meet to make the illusion of a large number. If you ve ever had the problem of needing to know what time it is and can t seem to find a clock, this may solve your problems as it s 51 x 18 . If you re late for anything you can t say you weren t paying attention to the time. This is actually at a gallery currently, but if you really want one, I m sure there are some fun tutorials online.. ...
When one eats may be as important as what one eats. New research at the Weizmann Institute of Science and in Germany, which recently appeared in the Proceedings of the National Academy of Sciences (PNAS), suggests that the cells power plants - the mitochondria - are highly regulated by the bodys biological, or circadian, clocks. This may help explain why people who sleep and eat out of phase with their circadian clocks are at higher risk of developing obesity, diabetes and metabolic syndrome.. Dr. Gad Asher of the Weizmann Institutes Biomolecular Sciences Department, who led the study, explains that circadian clocks, which are found in living things from bacteria to flies and humans, control our rhythms of sleep, activity, eating and metabolism. In a sense, he says, its like a daily calendar, telling the body what to expect, so it can prepare for the future and operate optimally.. Dr. Adi Neufeld-Cohen, of Ashers group, in collaboration with Dr. Maria S. Robles and Prof. Matthias Mann ...
When one eats may be as important as what one eats. New research at the Weizmann Institute of Science and in Germany, which recently appeared in the Proceedings of the National Academy of Sciences (PNAS), suggests that the cells power plants - the mitochondria - are highly regulated by the bodys biological, or circadian, clocks. This may help explain why people who sleep and eat out of phase with their circadian clocks are at higher risk of developing obesity, diabetes and metabolic syndrome.. Dr. Gad Asher of the Weizmann Institutes Biomolecular Sciences Department, who led the study, explains that circadian clocks, which are found in living things from bacteria to flies and humans, control our rhythms of sleep, activity, eating and metabolism. In a sense, he says, its like a daily calendar, telling the body what to expect, so it can prepare for the future and operate optimally.. Dr. Adi Neufeld-Cohen, of Ashers group, in collaboration with Dr. Maria S. Robles and Prof. Matthias Mann ...
By default, all articles on GreenMedInfo.com are sorted based on the content type which best reflects the data which most users are searching for. For instance, people viewing substances are generally most interested in viewing diseases that these substances have shown to have positive influences. This section is for allowing more advanced sorting methods. Currently, these advanced sorting methods are available for members only. If you are already a member, you can sign in by clicking here. If you do not currently have a user account, and would like to create one/become a member, click here to begin the singup process ...
Synchrony of the mammalian circadian clock is achieved by complex transcriptional and translational feedback loops centered on the BMAL1:CLOCK heterodimer. Modulation of circadian feedback loops is essential for maintaining rhythmicity, yet the role of transcriptional coactivators in driving BMAL1:CLOCK transcriptional networks is largely unexplored. Here, we show diurnal hepatic steroid receptor coactivator 2 (SRC-2) recruitment to the genome that extensively overlaps with the BMAL1 cistrome during the light phase, targeting genes that enrich for circadian and metabolic processes. Notably, SRC-2 ablation impairs wheel-running behavior, alters circadian gene expression in several peripheral tissues, alters the rhythmicity of the hepatic metabolome, and deregulates the synchronization of cell-autonomous metabolites. We identify SRC-2 as a potent coregulator of BMAL1:CLOCK and find that SRC-2 targets itself with BMAL1:CLOCK in a feedforward loop. Collectively, our data suggest that SRC-2 is a ...
Plasma is all about Clocks. Its an old joke, but it contains a kernel of truth. The clock is the one element of the desktop most people depend on, and it can be a valuable conduit for information they need. This page will co-ordinate all the resources around the Plasma Clock and plans for its future. == Resources == [http://userbase.kde.org/Plasma/Clocks UserBase Page] [https://bugs.kde.org/buglist.cgi?order=Importance&query_format=advanced&bug_status=UNCONFIRMED&bug_status=NEW&bug_status=ASSIGNED&bug_status=REOPENED&component=widget-clock&product=plasma KDE Bugzilla all open Plasma Clock bugs] [http://community.kde.org/Plasma/Tasks#Calendar.2FClock_Plasmoids Plasma Tasks List for Clocks] == Current Implementation == The current implementation can be found in the following locations. [https://projects.kde.org/projects/kde/kde-workspace/repository/revisions/master/show/plasma/generic/dataengines/time Time DataEngine] - Provides current Time ...
Buy Ticking Clock Loops Pack by ShahruhAudio on AudioJungle. 4 various ticking clock loops Durations: ticking clock1 0:04 ticking clock2 0:08 ticking clock3 0:08 ticking clock4 0...
Brown, S. A. & Azzi, A. (2013). "Peripheral circadian oscillators in mammals". Circadian clocks. Berlin: Springer. pp. 45-66. ... When travelling across a number of time zones, the body clock (circadian rhythm) will be out of synchronisation with the ... Melatonin receptors are situated on the suprachiasmatic nucleus, which is the anatomical site of the circadian clock. The ... There are two separate processes related to biological timing: circadian oscillators and homeostasis. The circadian system is ...
... but both WC-1 and WC-2 are required for the circadian clock to run. Because the core of the clock is based on a rhythmic ... The White Collar Complex (WCC), the heterodimer of WC-1 and WC-2, acts as a positive element in the circadian clock. WCC serves ... Crosthwaite SK, Loros JJ, Dunlap JC (Jun 1995). "Light-induced resetting of a circadian clock is mediated by a rapid increase ... Cha J, Zhou M, Liu Y (2015). Methods to study molecular mechanisms of the Neurospora circadian clock. Methods in Enzymology. ...
The change in the phenotype can be a result of genetic modification of circadian clock gene, high fat diet, disruption of the ... Eckel-Mahan, Kristin; Sassone-Corsi, Paolo (2016-11-13). "Metabolism and the Circadian Clock Converge". Physiological Reviews. ... The changes in the light/dark cycle of laboratories can alter their circadian rhythm which can affect their metabolism. Besides ... circadian cycle by changes in light and dark cycle, or a combination of all the factors. Further research is required to find ...
This clock is what is referred to as the body's circadian rhythm and it naturally is responsive to light. Melatonin levels ... "What is Circadian Rhythm / Body Clock?". Sleep.org. Retrieved 9 November 2019. Wilkin, David Anderson, Rebecca. "What staring ... The light screens emit are in a similar spectrum of sunlight, but the blue light emission is what human circadian rhythms are ... Dark therapy Delayed sleep phase disorder f.lux Light effects on circadian rhythm Night Shift (software) Red Moon (software) ...
This gene regulates the circadian clock and a variant of it was found in families that demonstrated advanced sleep-phase ... "Epidemiology of the human circadian clock". Sleep Medicine Reviews. 11 (6): 429-438. doi:10.1016/j.smrv.2007.07.005. ISSN 1087- ... As circadian rhythm is independent of the number of hours of sleep a person needs, Roenneberg calculates the rhythm based on ... Forced to arise earlier than their circadian rhythm dictates, they have a low body temperature and may require a few hours to ...
Ercolani L, Ferrari A, De Mei C, Parodi C, Wade M, Grimaldi B (October 2015). "Circadian clock: Time for novel anticancer ... It has been used in the study of the regulation of the circadian rhythm and its links to immune system function, inflammation ... March 2012). "Regulation of circadian behaviour and metabolism by synthetic REV-ERB agonists". Nature. 485 (7396): 62-8. ... December 2014). "Pharmacological targeting of the mammalian clock regulates sleep architecture and emotional behaviour". Nature ...
"The circadian clock: from molecules to behaviour". Ann. Med. 27 (4): 481-90. doi:10.3109/07853899509002457. PMID 8519510. ... There is good evidence that some basic aspects of human behaviour, such as circadian rhythms are genetically-based, but it is ...
Biological clocks and circadian timing in cells". EMBO Reports. 6 Spec No (Suppl 1): S9-13. doi:10.1038/sj.embor.7400424. PMC ... In 2000, using their rodent model, they discovered the existence of circadian clocks in peripheral organs of mammals. This ... Rensing L, Ruoff P (September 2002). "Temperature effect on entrainment, phase shifting, and amplitude of circadian clocks and ... Fu, Minnie; Yang, Xiaoyong (15 August 2017). "The sweet tooth of the circadian clock". Biochemical Society Transactions. 45 (4 ...
... "microRNA modulation of circadian-clock period and entrainment". Neuron. 54 (5): 813-29. doi:10.1016/j.neuron.2007.05.017. PMC ... where miR-132 is thought be involved in resetting the circadian clock in response to light. Inflammatory mediators such as ...
1990 - Human circadian clock is highly light sensitive. 1995 - Blind people can still retain sleep rhythms if their eyes remain ... Li MD, Li CM, Wang Z (Sep 2012). "The role of circadian clocks in metabolic disease". Yale J Biol Med. 85 (3): 387-401. PMC ... His team discovered that light transduced by non-visual input (melanopsin activation) could reset the circadian clock in ... 2013.[12] "Human Biological Clock Set Back an Hour." Human Biological Clock Set Back an Hour. N.p., n.d. Web. 24 Apr. 2013. ...
"Interactions between metabolism and circadian clocks: reciprocal disturbances". Ann N Y Acad Sci. 1243 (1): 30-46. Bibcode: ... The circadian phase is relatively fixed in humans; attempting to shift it so that an individual is alert during the circadian ... Shift work is an employment practice designed to make use of, or provide service across, all 24 hours of the clock each day of ... This may be due to alterations in circadian rhythm: melatonin, a known tumor suppressor, is generally produced at night and ...
Later studies also implicated a brain-based circadian clock as the regulator controlling the release of EH. As a junior fellow ... Eclosion rhythms were only abolished with the removal of the brain, indicating that the circadian clock is located within the ... These results confirmed Truman's previous findings that the circadian clock is located within the brain and that the factor ... Similar experiments focusing on the role of the circadian clock in regulating flight rhythms confirmed that extraretinal ...
"Oxyntomodulin regulates resetting of the liver circadian clock by food". www.uni-luebeck.de. University of Lübeck. 30 April ... Oxyntomodulin has been linked to entrainment of the liver's circadian clock. Oxyntomodulin has been investigated as a blood- ...
Yang Y, Cheng P, Liu Y (April 2002). "Regulation of the Neurospora circadian clock by casein kinase II". Genes & Development. ... "Setting clock speed in mammals: the CK1 epsilon tau mutation in mice accelerates circadian pacemakers by selectively ... "High-throughput chemical screen identifies a novel potent modulator of cellular circadian rhythms and reveals CKIα as a clock ... "A Length Polymorphism in the Circadian Clock Gene Per3 is Linked to Delayed Sleep Phase Syndrome and Extreme Diurnal Preference ...
CS1 maint: discouraged parameter (link) Dodd, A. N. (2005). "Plant Circadian Clocks Increase Photosynthesis, Growth, Survival, ...
Allada R, White NE, So WV, Hall JC, Rosbash M (May 1998). "A mutant Drosophila homolog of mammalian Clock disrupts circadian ... Tanoue S, Krishnan P, Krishnan B, Dryer SE, Hardin PE (April 2004). "Circadian clocks in antennal neurons are necessary and ... Research from 2012 on sleep architecture and nutrition found that circadian clock mutants, including cyc01 still maintained a ... Helfrich-Förster C (March 2005). "Neurobiology of the fruit fly's circadian clock". Genes, Brain, and Behavior. 4 (2): 65-76. ...
... they travel during the day and use a circadian clock based on the sun's position in the sky to orient themselves. This clock ... The importance of the circadian clock in the function of this time-compensated sun compass system has led to investigation into ... While neural processing may occur in the monarch's brain, research indicates that the actual circadian clock underlying the ... Merlin, C.; Gegear, R. J.; Reppert, S. M. (2009-09-25). "Antennal Circadian Clocks Coordinate Sun Compass Orientation in ...
Merlin, Christine; Gegear, Robert J.; Reppert, Steven M. (September 2009). "Antennal circadian clocks coordinate sun compass ... Antennal clocks exist in monarchs, and they are likely to provide the primary timing mechanism for sun compass orientation. In ...
ISBN 978-0-665-75744-0. Merlin, Christine; Gegear, Robert J.; Reppert, Steven M. (2009). "Antennal circadian clocks coordinate ...
There are candidate genes (called clock genes) that exist in most cells in the body and brain, referred to as the circadian ... Allebrandt, K.V.; Roenneberg, T. (2008). "The search for circadian clock components in humans: New perspectives for association ... The Circadian Type Inventory, developed by Folkard (1987), is an improved version of the 20-item Circadian Type Questionnaire ( ... "Dictionary of Circadian Physiology". Circadian Rhythm Laboratory, University of South Carolina Salkehatchie, Walterboro campus ...
Bacterial circadian rhythms Biological clock (aging) Circadian rhythm Circannual cycle Circaseptan, 7-day biological cycle ... It is regulated by circadian clocks. The circadian rhythm can further be broken down into routine cycles during the 24-hour day ... In some cases, multi-trophic systems may exhibit rhythms driven by the circadian clock of one of the members (which may also be ... ISBN 978-0-471-56802-5. Hastings, Michael, "The brain, circadian rhythms, and clock genes". Clinical review" BMJ 1998;317:1704- ...
"Decoupling circadian clock protein turnover from circadian period determination". Science. 347 (6221): 1257277. doi:10.1126/ ... O'Neill, John S; Reddy, Akhilesh B (2011). "Circadian clocks in human red blood cells". Nature. 469 (7331): 498-503. doi: ... Dunlap, Jay C (1999). "Molecular Bases for Circadian Clocks". Cell. 96 (2): 271-90. doi:10.1016/S0092-8674(00)80566-8. PMID ... Rosbash, Michael (2009). "The Implications of Multiple Circadian Clock Origins". PLoS Biology. 7 (3): e62. doi:10.1371/journal. ...
... temporal stopping of circadian clocks) is caused by desynchronization of multiple cellular circadian oscillators, and that ... He is known for his studies on the circadian clock. Hiroki R. Ueda was born in Fukuoka, Japan, in 1975. He graduated from the ... He has an expertise in systems biology and focus on chronobiology by investigating mammalian circadian clocks and sleep/wake ... He determined a basic structure of a transcriptional circuit of mammalian circadian clocks and identified multiple delayed ...
It is thought that sufferers have a weak circadian clock. The risk for the disorder increases with age, but only due to ... Dement WC (January 22, 1999). "Circadian Rhythm Information". Retrieved 2010-10-07. Zee PC, Vitiello MV (June 2009). "Circadian ... Because of the changes in sleep/wake time, and because this is a rare disorder, initially it can seem like another circadian ... Irregular sleep-wake rhythm is a rare form of circadian rhythm sleep disorder. It is characterized by numerous naps throughout ...
Roenneberg, T; Kantermann, T; Juda, M; Vetter, C; Allebrandt, KV (2013). "Light and the human circadian clock". Handbook of ... Kantermann, T; Juda, M; Merrow, M; Roenneberg, T (2007). "The human circadian clock's seasonal adjustment is disrupted by ... Allebrandt, K.V.; Roenneberg, T. (2008). "The search for circadian clock components in humans: New perspectives for association ... Allebrandt, K.V.; Roenneberg, T. (2008). "The search for circadian clock components in humans: New perspectives for association ...
Sleep deprivation and constant dim lighting may mask the endogenous clock or affect circadian phase. For example, it has been ... Mistlberger, RE; Belcourt, J; Antle, MC (June 2002). "Circadian clock resetting by sleep deprivation without exercise in Syrian ... "Persistence of the circadian thyrotropin rhythm under constant conditions and after light-induced shifts of circadian phase". ... Monk, TH; Buysse, DJ; Reynolds CF, 3rd; Berga, SL; Jarrett, DB; Begley, AE; Kupfer, DJ (March 1997). "Circadian rhythms in ...
This allows the Bristlemouth to have control over its circadian clock and seasonal behavior. Due to the small size of the fish ...
Merrow, M, Brunner M, Roenneberg T (June 1999). "Assignment of circadian function for the Neurospora clock gene frequency" (PDF ...
"Stochastic gene expression out-of-steady-state in the cyanobacterial circadian clock". Nature. 450 (7173): 1249-52. Bibcode: ...
"Structure and function from the circadian clock protein KaiA of Synechococcus elongatus: a potential clock input mechanism". ... S. elongatus has a circadian clock with an oscillator based only on three proteins, KaiA, KaiB, and KaiC where rhythm is ... PMID 8665856.CS1 maint: multiple names: authors list (link) Johnson CH, Golden SS, Ishiura M, Kondo T (1996). "Circadian clocks ... Golden SS (2004). "Meshing the gears of the cyanobacterial circadian clock". Proc Natl Acad Sci USA. 101 (38): 13697-8. doi: ...
"Circadian Rhythm Sleep Disorder" (PDF). American Academy of Sleep Medicine. 2008. Archived from the original (PDF) on 2010-08- ... Blind people may use talking equipment such as thermometers, watches, clocks, scales, calculators, and compasses. They may also ... a condition in which a person's circadian rhythm, normally slightly longer than 24 hours, is not entrained (synchronized) to ... "Circadian rhythm abnormalities in totally blind people: incidence and clinical significance". J. Clin. Endocrinol. Metab. 75 ...
This discovery solidified doubletime as a necessary part of the circadian clock.[18] ... "Light-induced degradation of TIMELESS and entrainment of the Drosophila circadian clock". Science. 271 (5256): 1736-1740. doi: ... Following the discovery of per, the Young lab looked for additional circadian genes. In late 1980s, Amita Sehgal, Jeff Price, ... The location and composition of these clocks were unknown, and this sparked Michael Young's interest at an early age.[6] ...
According to molecular clock dating, these two suborder primate branches parted ways about 63 to 60 million years ago.[143] ... It has been observed that while serum or blood plasma concentrations follow a circadian rhythm or reflect short-term dietary ...
When those patterns are disrupted, they disrupt the natural circadian cycle. Circadian disruption may lead to numerous health ... entering the eye that affects the human body's clock. ... The human circadian system is entrained to a 24-hour light-dark ... "A new approach to understanding the impact of circadian disruption on human health". J Circadian Rhythms. 6: 7. doi:10.1186/ ... In order to specifically measure the amount of light entering the eye, personal circadian light meter called the Daysimeter has ...
Cryptochromes absorb blue light and UV-A. Cryptochromes entrain the circadian clock to light.[6] It has been found that both ... with the rhythms of the circadian clock that allows plants to measure the length of the night. Other than flowering, ...
Dibner C, Schibler U, Albrecht U (2010). "The mammalian circadian timing system: organization and coordination of central and ... peripheral clocks". Annual Review of Physiology. 72: 517-49. doi:10.1146/annurev-physiol-021909-135821. PMID 20148687. ... ACTH is also related to the circadian rhythm in many organisms.[2] ...
... including several that are involved in controlling circadian rhythm, such as CLOCK.[8] The groups led by James Lupski (Baylor ... 2001). "Inversion of the circadian rhythm of melatonin in the Smith-Magenis syndrome". J Pediatr. 139 (1): 111-116. doi:10.1067 ... results in disruption of CLOCK gene transcription and reveals an integral role for RAI1 in the maintenance of circadian ... due to an inverted circadian rhythm of melatonin.[4] ... improve sleep and behavioural disturbances in a circadian ...
"Jet lag and shift work sleep disorders: How to help reset the internal clock". www.mdedge.com. Retrieved 2019-06-24.. ... Shift work sleep disorder (SWSD) is a circadian rhythm sleep disorder characterized by insomnia and excessive sleepiness ... Brain arousal is stimulated by the circadian system during the day and sleep is usually stimulated at night.[13] The rhythms ... To maximize a delay of the body clock, bright light exposure should occur in the evening or first part of the night, and bright ...
Galison, Peter (2003). Einstein's clocks, Poincaré's maps: Empires of time. New York: W.W. Norton & Co. ISBN 0-393-02001-0.. ... All clocks within each zone would be set to the same time as the others, but differed by one hour from those in the neighboring ... Greenwich Mean Time, where all clocks in Britain were set to the same time, was established to solve this problem. Chronometers ... Prior to the introduction of standard time, each municipality throughout the civilized world set its official clock, if it had ...
... of melatonin shift the circadian clock earlier, thus promoting earlier sleep onset and morning awakening.[68] In humans, 90% of ... it will shift the phase of the human circadian clock (sleep, endogenous melatonin, core body temperature, cortisol) to earlier ... Circadian rhythmEdit. In animals, melatonin plays an important role in the regulation of sleep-wake cycles. Human infants' ... Lewis, Alan (1999). Melatonin and the Biological Clock. McGraw-Hill. p. 23. ISBN 978-0-87983-734-1.. ...
ATOH1 • AhR • AHRR • ARNT • ASCL1 • BHLHB2 • BMAL (ARNTL, ARNTL2) • CLOCK • EPAS1 • HAND (1, 2) • HES (5, 6) • HEY (1, 2, L) • ... 1998). "Disruption of retinoid-related orphan receptor beta changes circadian behavior, causes retinal degeneration and leads ...
Doi M, Hirayama J, Sassone-Corsi P (May 2006). "Circadian regulator CLOCK is a histone acetyltransferase". Cell. 125 (3): 497- ... CLOCK is a circadian rhythm master regulator that functions with BMAL1 to carry out its HAT activity.[9] ... These include p300/CBP, nuclear receptor coactivators (e.g., ACTR/SRC-1), TAFII250, TFIIIC, Rtt109, and CLOCK. p300/CBP are ... The HAT activities of the human TAFII250 and CLOCK coactivators have not been studied as extensively. TAFII250 is one of the ...
"Orchestrated Transcription of Key Pathways in Arabidopsis by the Circadian Clock". Science. 290 (5499): 2110-2113. doi:10.1126/ ... Floral scent emissions of most flowering plants vary predictably throughout the day, following a circadian rhythm. This ... "Regulation of Circadian Methyl Benzoate Emission in Diurnally and Nocturnally Emitting Plants". The Plant Cell. 13 (10): 2333- ...
... phase shifts of the circadian biological clock through increases in cAMP production". Neuropharmacology 46 (1): 52-62. PMID ...
"Antennal circadian clocks coordinate sun compass orientation in migratory monarch butterflies". Science. 325 (5948): 1700-1704 ... Antennal clocks exist in monarchs, and they are likely to provide the primary timing mechanism for sun compass orientation.[13] ...
... it will shift the phase of the human circadian clock (sleep, endogenous melatonin, core body temperature, cortisol) to earlier ...
"The pineal gland is critical for circadian Period1 expression in the striatum and for circadian cocaine sensitization in mice ... "Regulation of dopaminergic transmission and cocaine reward by the Clock gene". Proc Natl Acad Sci USA 102 (26): 9377-81. doi ...
Other examples include Central and peripheral circadian clocks,[14] and central versus peripheral vision.[15] ... "Central and Peripheral Circadian Clocks in Mammals". Annual Review of Neuroscience. 35: 445-462. doi:10.1146/annurev-neuro- ...
Leon Kreitzman; Russell G. Foster (2004). Rhythms of life: the biological clocks that control the daily lives of every living ... Russell Grant Foster, CBE, FRS FMedSci (born 1959)[1] is a British professor of circadian neuroscience, the Director of the ... The Biological Clocks that Control the Daily Lives of Every Living Thing[14][15] and Seasons of Life: The Biological Rhythms ... Foster hypothesized that circadian photoreception occurs with a small number of cones without an outer layer or that an ...
6-hour clock (Italian). *6-hour clock (Thai). *12-hour clock. *24-hour clock ...
Antle, MC; Silver, R. Orchestrating time: arrangements of the brain circadian clock (PDF). Trends in Neurosciences. 2005, 28 (3 ... Konopka, RJ; Benzer, S. Clock Mutants of Drosophila melanogaster. Proc. Natl. Acad. Sci. U.S.A. 1971, 68 (9): 2112-6. PMC ... An unusual coding sequence from a Drosophila clock gene is conserved in vertebrates. Nature. 1985, 317 (6036): 445-8. PMID ...
Dallaspezia S, Benedetti F (December 2009). "Melatonin, circadian rhythms, and the clock genes in bipolar disorder". Curr ... Both mania and depression are characterized by disruptions in normal mood, psychomotor activity, circadian rhythm, and ... Circadian rhythms and regulation of the hormone melatonin also seem to be altered.[74] ... "Circadian Rhythm Hypotheses of Mixed Features, Antidepressant Treatment Resistance, and Manic Switching in Bipolar Disorder" ...
Physiological and molecular characteristics of plant circadian clocks. Mol biol of circadian rhythms. A. Sehgal. Hoboken, John ... Signs of the time: environmental input to the circadian clock. *↑ Farré EM, Harmer SL, Harmon FG, Yanovsky MJ, Kay SA. 2005. ... Signs of the time: environmental input to the circadian clock. J Exp Bot, 53, 1535-1550. Devlin, P. F. 2002. ... Overlapping and distinct roles of PRR7 and PRR9 in the Arabidopsis circadian clock. Current Biology 15: 47-54. PMID: 15649364 ...
In some diver training courses for these types of diving, divers are taught to plan and monitor what is called the oxygen clock ... Hof, DG; Dexter, JD; Mengel, CE (1971). "Effect of circadian rhythm on CNS oxygen toxicity". Aerospace Medicine. 42 (12): 1293- ... the diver obtains more time on the oxygen clock by diving at a shallower depth, by breathing a less oxygen-rich gas, or by ... Sensitivity to central nervous system oxygen toxicity has been shown to be affected by factors such as circadian rhythm, drugs ...
"Simple sequence repeats provide a substrate for phenotypic variation in the Neurospora crassa circadian clock". PLoS ONE. 2 (8 ... control the duration of its circadian clock cycles.[32] Effects on gene regulation[edit]. Length changes of microsatellites ...
Coordination between circadian and metabolic signaling within the hypothalamus is essential for an adequate temperature control ... The balance between the releases of neuropeptides derived from the biological clock and from a metabolic sensory organ as the ... It's known that mammals have a circadian rhythm in body temperature (Tb) that depend on the integrity of the suprachiasmatic ... These observations show that brain areas involved in circadian and metabolic functions of the body need to interact to produce ...
This clock is found in a wide range of fly cells, but the clock-bearing cells that control activity are several dozen neurons ... Circadian rhythms are also subject to developmental plasticity. Light conditions during development affect daily activity ... In 1971, Ron Konopka and Seymour Benzer published "Clock mutants of Drosophila melanogaster", a paper describing the first ... Young for their discoveries of molecular mechanisms controlling the circadian rhythm". Nobelprize.org. 2 October 2017. ...
... "body clock". They can coordinate peripheral "clocks" and direct the pineal gland to secrete the hormone melatonin. ... The retinohypothalamic tract (RHT) is a photic neural input pathway involved in the circadian rhythms of mammals.[1] The origin ... The synapse of glutamate to the SCN has been shown to cause phase shifts in circadian rhythms, discussed more in detail later. ... The SCN of the hypothalamus contains an endogenous pacemaker that regulates circadian rhythms.[5] The zeitgeber found to have ...
SCN and circadian rhythmEdit. The SCN coordinates daily timekeeping in the body and VIP plays a key role in communication ... The mPer1 promoter has CRE domains and thus provides the mechanism for VIP to regulate the molecular clock itself. Then it will ... One region includes a specific area of the suprachiasmatic nuclei (SCN), the location of the 'master circadian pacemaker'.[18] ... Circadian time is likely to affect the synapses rather than the organization of VIP circuits.[11] ...
This book sheds new light on the molecular mechanisms that generate circadian rhythms. It examines how biological rhythms ... Mammalian Circadian Clocks and Metabolism: Navigating Nutritional Challenges in a Rhythmic World ... This book sheds new light on the molecular mechanisms that generate circadian rhythms. It examines how biological rhythms ... this book serves as a guide for physicians and scientists who wish to learn more about the impact of circadian rhythms on ...
Further clues into the regulation of circadian clocks are the subject of two reports. In plants and insects, cryptochromes ( ... In Drosophila, three of the critical clock genes, period (per), timeless (tim), and Drosophila Clock (dClk), are expressed ... role of CRY1 and light-independent role of CRY1 and light-iIndependent role of CRY1 and CRY2 in the mammalian circadian clock. ... show that CRY1 and CRY2 play a central role in the mammal clock, but in a light-independent fashion--they appear to regulate ...
ClockΔ19) had prolonged and non-productive parturition, suggestive of a role for circadian clocks in the parturition event. ... A key study to draw attention to the potential role of the circadian clock and pregnancy was that of Miller et al (2004), who ... A growing body of research reveals circadian clock gene expression in the uterus of non-pregnant and pregnant mammals. ... 2010) examined expression of circadian clock genes in the mouse uterus in late pregnancy and found significant daily mRNA ...
... 25.09.2015. A circadian clock is not mandatory for living beings to adapt their activities to a ... The circadian clock sets the pace. Nevertheless, clockless fruit flies do show some behavioural differences. The clock seems to ... But this view of circadian clocks as central mechanisms that drive circadian rhythms was recently challenged. Scientists had ... And ideally its circadian clock will make the animal stop its activities before it is dark the next day. ...
... circadian clocks include Single-cell Resolution Fluorescence Live Imaging of Drosophila Circadian Clocks in Larval Brain ... Monitoring Cell-autonomous Circadian Clock Rhythms of Gene Expression Using Luciferase Bioluminescence Reporters, In Vitro ... Rapid Analysis of Circadian Phenotypes in Arabidopsis Protoplasts Transfected with a Luminescent Clock Reporter, A ... Parallel Measurement of Circadian Clock Gene Expression and Hormone Secretion in Human Primary Cell Cultures, ...
... which was found to be governed by the bodys internal biological clock. ... The bodys circadian clock controls an early-evening agitation known as sundowning, which is common in patients with ... Next, the scientists used genetics-based tools to manipulate neurons known to regulate the central circadian clock. When Saper ... But whether the circadian clock regulated aggressive behavior was unknown.. .blockquote{margin: 15px 0; padding: 10px; ...
If you are a society or association member and require assistance with obtaining online access instructions please contact our Journal Customer Services team ...
New discoveries about the circadian-clock machinery in the precursors to fat cells may explain why shift workers are prone to ... Stem cells that generate fat tissue have circadian clock. New discoveries about the circadian-clock machinery in the precursors ... Prior research had shown that mature fat cells have a circadian clock, but it was not known if a clock existed in their stem ... have a circadian clock that functions differently than the kind found in most of the bodys other cells. Perturbing the clock ...
... clocks,improves,cell,adaptability,biological,biology news articles,biology news today,latest biology news,current biology news, ... The circadian clocks that control and influence dozens of basic biolog...,Snooze,button,on,biological, ... Snooze button on biological clocks improves cell adaptability. ...The circadian clocks that control and influence dozens of ... The circadian clocks that control and influence dozens of basic biological processes have an unexpected "snooze button" that ...
CLOCK p-BMAL1:p-CLOCK,NPAS2. PER2 NR1D1 HDAC3 ARNTL FBXL3. CLOCK TGS1 p-S133-CREB1 BMAL1:CLOCK,NPAS2. NR3C1:Dexamethasone. ... p-BMAL1:p-CLOCK,NPAS2:PER2 gene. BMAL1:CLOCK,NPAS2. activates circadian. gene expression. CREM isoform 6 (ICER1) p-S-CLOCK CRY1 ... CLOCK gene. R-HSA-1368119 (Reactome) CLOCK gene. R-HSA-5663271 (Reactome) CLOCK,NPAS2. R-HSA-400228 (Reactome) CLOCK. Arrow. R- ... p-BMAL1:p-CLOCK,NPAS2. R-HSA-400256 (Reactome) p-BMAL1:p-CLOCK,NPAS2. R-HSA-5663118 (Reactome) p-BMAL1:p-CLOCK,NPAS2. R-HSA- ...
The circadian or inner clock coordinates the sleep-wake rhythm and many other body processes that regulate, ... ... Structural biologists have made important progress towards better understanding the functioning of the circadian clock. ... At the heart of the circadian clock More information: I. Schmalen et al., Interaction of Circadian Clock Proteins CRY1 and PER2 ... a class of proteins associated with the circadian clock in mammals. In addition to regulating circadian rhythm, these also ...
Our circadian clocks are centered in the brain and control key physiological processes-sleep, body temperature, organ function ... The researchers found that autophagic digestion selectively targets proteins controlling the circadian clock, most notably the ... clock protein CRY1. CRY1 is a key regulator of circadian cycles and also helps maintain blood glucose levels by inhibiting the ... Disrupting the clock can potentially lead to diabetes and other metabolic diseases. ...
Zebrafish circadian clocks: cells that see light. T.K. Tamai, A.J. Carr, D. Whitmore ... Zebrafish circadian clocks: cells that see light Message Subject (Your Name) has forwarded a page to you from Biochemical ... In the classical view of circadian clock organization, the daily rhythms of most organisms were thought to be regulated by a ... It is also clear that the circadian clock in zebrafish regulates the timing of the cell cycle, demonstrating the wide impact ...
Endogenous circadian clocks ensure that temporal patterns of physiology and behavior predict environmental changes determined ... Such clocks are synchronized by the daily light-dark cycle. ... basis for the adaptation of the mammalian circadian clock to ... Circadian clock misalignment and consequences Citation: Separating morning and evening in the circadian clock of mammals (2005 ... Such clocks are synchronized by the daily light-dark cycle. A key question for circadian biologists concerns the way in which ...
To test the hypothesis that the circadian clock directly influences myocardial metabolism, a cardiomyocyte-specific circadian ... Recent studies suggest that the transcriptional co-activator, PGC1α, is an integral component of the mammalian circadian clock ... In conclusion, we report that disruption of the circadian clock within the cardiomyocyte decreases mitochondrial biogenesis and ... Abstract 275: The Intrinsic Circadian Clock within the Cardiomyocyte Regulates Myocardial Efficiency and Mitochondrial Function ...
Variation in circadian clocks[edit]. While a precise 24-hour circadian clock is found in many organisms, it is not universal. ... Plant clocks[edit]. The circadian clock in plants has completely different components to those in the animal, fungus or ... A circadian clock, or circadian oscillator, is a biochemical oscillator that cycles with a stable phase and is synchronized ... Mammalian clocks[edit]. Selective gene knockdown of known components of the human circadian clock demonstrates both active ...
... but blogging audience forces me to occasionally look into human clocks from a medical perspective. ... You probably realize by now that my expertise is in clocks and calendars of birds, ... Molecular Mechanism of Circadian Rhythm Generation in Mammals. Let me now try to explain how the mammalian circadian clock ... Clocks and Bipolar Disorder. This is an interesting short review about the link between the circadian clock and the manic/ ...
If you ever glanced at the circadian literature, you have probably encountered the statement that circadian rhythms are ... Clocks in Bacteria III: Evolution of Clocks in Cyanobacteria, Clocks in Bacteria IV: Clocks in other bacteria, Clocks in ... Circadian Clocks in Microorganisms, Clocks in Bacteria I: Synechococcus elongatus, Clocks in Bacteria II: Adaptive Function of ... Clocks in Bacteria IV: Clocks in other bacteria. Fourth in the five-part series on clocks in bacteria (from April 30, 2006): ...
However, FRP or clock-null mutations of circadian clock genes in Drosophila (per) or Neurospora (frq) do not obviously impair ... The Circadian Clock in Arabidopsis Roots Is a Simplified Slave Version of the Clock in Shoots ... The circadian clock controls the expression pattern of the circadian input photoreceptor, phytochrome B ... Quinone sensing by the circadian input kinase of the cyanobacterial circadian clock ...
Compelling evidence points toward a tight intertwining between circadian rhythms and metabolism. Circadian clocks play a major ... The mammalian circadian timing system consists of a central pacemaker in the brain that synchronizes subsidiary oscillators in ... Concomitantly, clocks are tightly coupled to cellular metabolism and respond to feeding cycles. Our overarching goal is to ... While the brains master clock is entrained by daily light-dark cycles, feeding time appears to be the dominant timing cue for ...
Circadian Rhythms and Circadian Clock. Circadian Rhythms. *Are internally driven cycles that rise and fall during the 24-hour ... Circadian Clock. The circadian clock has an internally driven 24-hour rhythm that tends to run longer than 24 hours but resets ... The master circadian clock in the brain (see Figure 2) synchronizes and controls these cycles so they work together. ... The internal body clock sets the timing for many circadian rhythms, which regulate processes such as ...
The molecular mechanisms of the clock are being studied at the biochemical and genomic levels. ... Joseph Takahashi is interested in understanding the genetic and molecular basis of circadian rhythms as well as other complex ... The Clock mutation lengthens circadian period by 4 hours in homozygous mutants, followed by a complete loss of circadian ... Molecular Mechanism of the Clock. The circadian clock in mammals is composed of an autoregulatory transcriptional network with ...
A new study now shows that a central clock governs the circadian rhythms in certain cases. ... Whether and how these clocks are connected with each other is still a largely open question. ... Multiple biological clocks control the daily rhythms of physiology and behavior in animals and humans. ... Rather, most organisms have a multitude of circadian clocks: a central clock in the brain and various peripheral clocks in the ...
Most clocks use the light-dark cycle as environmental signal (zeitgeber) for this active synchronisation. How we... ... The circadian clock can only reliably fulfil its function if it is stably entrained. ... Light and the Human Circadian Clock. In: Kramer A., Merrow M. (eds) Circadian Clocks. Handbook of Experimental Pharmacology, ... The circadian clock can only reliably fulfil its function if it is stably entrained. Most clocks use the light-dark cycle as ...
Circadian clock cryptochrome proteins regulate autoimmunity. Qi Cao, Xuan Zhao, Jingwen Bai, Sigal Gery, Haibo Sun, De-Chen Lin ... C1qa, C1qb, C1qc, C6, Fcgr3, and Fcgr4 were down-regulated, and circadian clock genes Per2, Per3, Nr1d1, and Nr1d2 were up- ... 2012) Circadian expression of clock genes in mouse macrophages, dendritic cells, and B cells. Brain Behav Immun 26:407-413. ... indicating that the intrinsic circadian clock regulates inflammatory innate immune functions (11). The circadian oscillations ...
Purchase Circadian Rhythms and Biological Clocks Part B, Volume 552 - 1st Edition. Print Book & E-Book. ISBN 9780128033807, ... Part IV: Circadian Rhythms in Humans *Chapter Eleven: Measuring Circadian Clock Function in Human Cells *Abstract ... Circadian Rhythms and Biological Clocks Part B, Volume 552 1st Edition. 0 star rating Write a review ... Circadian Rhythms and Biological Clocks Part A and Part B is an exceptional resource for anybody interested in the general area ...
... in the brain has a master circadian clock that manages cells, many of which have their own molecular clocks. ... According to the Cleveland Clinic, the circadian rhythm, otherwise known as the "internal body clock," manages the body´s 24- ... This study is the first to definitively prove that the body´s circadian biological clock controls insulin activity. ... The researchers used different approaches to disrupt the circadian clocks of individual mice. Measurements were taken at ...
... body clocks) present in different parts of the body determine when and how much energy must be supplied by mitochondria (the ... Circadian Rhythm may Help Regulate Inflammatory Diseases. Controlling of the circadian rhythm or biological clock may help ... Relationship between circadian clock and energy production The scientists also showed that the mitochondrial network loses its ... Study Identifies How Internal Circadian Clocks Encode External Daily Rhythms of Excitability. A mechanism through which ...
... to those who are pursuing a career in any of the life sciences as well as anyone who has run up against their biological clock. ... Circadian clocks serve to orchestrate physiology and metabolism in a coordinated way over the course of the day. Therefore, ... 6.2 The consequences of living against the clock11m. 6.3 Circadian changes and Pathologies - comorbidities or causal factors 3m ... We will discuss the elaborate molecular mechanisms that allow circadian clocks to produce their daily rhythms and to ...
All current models of the molecular circadian clockwork in eukaryotic cells are based on transcription-translation feedback ... clocks are fundamentally important for coordinated physiology in organisms as diverse as cyanobacteria and humans. ... Circadian clocks in human red blood cells Nature. 2011 Jan 27;469(7331):498-503. doi: 10.1038/nature09702. ... Circadian (∼24 hour) clocks are fundamentally important for coordinated physiology in organisms as diverse as cyanobacteria and ...
Circadian clock molecules in flies. The expression of circadian timing in individual neurones shows that it is not an emergent ... Circadian clock molecules in mammals. Studies in mammals have advanced our understanding of the clock mechanism in two ways. ... Circadian clock molecules in drosophila. Early cycle: Expression of the clock genes period (per) and timeless (tim) is ... hence circadian (approximately a day). Notwithstanding this inaccuracy, the circadian clock is extremely robust. It is capable ...
The kidneys contain a circadian clock that plays a key role in levels of certain blood components - such as lipids and amino ... Kidneys circadian clock regulates drug disposition, blood component levels. Published Friday 8 April 2016 Published Fri 8 Apr ... "Kidneys circadian clock regulates drug disposition, blood component levels." Medical News Today. MediLexicon, Intl., 8 Apr. ... The circadian clock is the bodys natural time-keeping mechanism, located in the suprachiasmatic nucleus of the brain. It ...
... to pathogenic invasion is controlled by circadian rhythms, researchers found. ... Circadian Clock Times Immune Response. The molecular response of an organism -- be it mouse or man -- to pathogenic invasion is ... To examine the influence of the circadian clock on immunity at the molecular level, Fikrigs group conducted a series of murine ... Source Reference: Silver A, et al "The circadian clock controls tool-like receptor 9-mediated innate and adaptive immunity" ...
One clock followed the artificially short 11-hr. day/11-hr. night schedule, while the other followed a longer cycle (>24 hrs ... In mammals, the endogenous daily pacemaker that regulates circadian rhythms like sleep and wakefulness is localized to a ... a regimen that effectively pushes the limits of the SCN s ability to set the clock to day length - researchers have discovered ... that underlies the workings of the circadian timing system. In humans, some of the symptoms arising from jet lag or rotating ...
Circadian clocks provide a competitive advantage in an environment that is heavily influenced by the rotation of the Earth, by ... Photosynthetic entrainment of the Arabidopsis thaliana circadian clock.. Haydon MJ1, Mielczarek O, Robertson FC, Hubbard KE, ... The production of sugars by photosynthesis is a key metabolic output of the circadian clock in plants. Here we show that these ... Circadian clocks comprise transcription-translation feedback loops, which are entrained by environmental signals such as light ...
Circadian-controlled gene oscillations in adipose tissues.. The presence of active circadian clocks in BAT, iWAT, and eWAT was ... the expression of Clock did not follow a consistent circadian pattern in any of these tissues. Others have shown that Clock ... Characterization of Peripheral Circadian Clocks in Adipose Tissues. Sanjin Zvonic, Andrey A. Ptitsyn, Steven A. Conrad, L. ... Characterization of Peripheral Circadian Clocks in Adipose Tissues. Sanjin Zvonic, Andrey A. Ptitsyn, Steven A. Conrad, L. ...
... where we find out about the Body Clock! We discover the constant chemical cascade that keeps your clock in check, and how not ... seeing the sun leads to S.A.D. We probe the plant clock to explore how trees tell the time, and why even plants can suffer from ... This is presumably some kind of clock phenomenon?. Russell - It seems to be associated with a clock. A bit of background on SAD ... 36:51 - Plants have Body Clocks too!. We know our body clocks control when we need to eat, sleep and perform other important ...
Per3 period circadian clock 3 [Mus musculus] Per3 period circadian clock 3 [Mus musculus]. Gene ID:18628 ... period circadian protein homolog 3. Names. circadian clock protein PERIOD 3. period homolog 3. ... Circadian rhythm, organism-specific biosystemCircadian rhythm is an internal biological clock, which enables to sustain an ... Circadian rhythm, conserved biosystemCircadian rhythm is an internal biological clock, which enables to sustain an ...
Circadian clock gene expression. In humans and rodents, the expression patterns of clock genes in a variety of tissues exhibit ... The molecular circadian clock. Heterodimers of the transcription factors BMAL1 and CLOCK upregulate the expression of many ... The aging clock: circadian rhythms and later life. Suzanne Hood1 and Shimon Amir2 1Department of Psychology, Bishops ... The circadian clock and pathology of the ageing brain. Nat Rev Neurosci. 2012;13(5):325-335.. View this article via: PubMed ...
The circadian rhythm that quietly pulses inside us all, guiding our daily cycle from sleep to wakefulness and back to sleep ... The circadian clock controls the daily cycle of sleep and wakefulness by inhibiting different parts of the brain by releasing ... The circadian rhythm that quietly pulses inside us all, guiding our daily cycle from sleep to wakefulness and back to sleep ... But when a hamster that lacks circadian rhythms is put back in the box, its as if it is a whole new world for the hamster. ...
Changing the circadian clock in mouse liver can alter how the body responds to diet and also change the microbes living in the ... Disrupting the circadian clock in mouse liver alters the gut microbiome. To investigate the connection between the circadian ... One involves the circadian clock, the internal mechanism that helps orchestrate body activities such as going to sleep or when ... "Lacking a gene in the liver that drives the circadian clock was sufficient to not only change the resiliency of these male mice ...
A new study of the brains master circadian clock - known as the suprachiasmatic nucleus, or SCN - reveals that a key pattern ... Wolpert, S. (2011, July 20). "New Evidence Of Age-Related Decline In The Brains Master Circadian Clock." Medical News Today. ... "New Evidence Of Age-Related Decline In The Brains Master Circadian Clock." Medical News Today. MediLexicon, Intl., 20 Jul. ... "These results indicate that the outputs of the central circadian clock start to decline in middle age and suggest that the same ...
  • This book sheds new light on the molecular mechanisms that generate circadian rhythms. (springer.com)
  • Offering a cross-section of expertise in both basic and translational (bench-to-bedside) research, this book serves as a guide for physicians and scientists who wish to learn more about the impact of circadian rhythms on physiological processes in health and disease. (springer.com)
  • 2009). Progesterone, but not estradiol, served to synchronize the circadian rhythms in these cells. (frontiersin.org)
  • The circadian clock is cell-autonomous and some, but not all cells of the body exhibit circadian rhythms in metabolism, cell division, and gene transcription. (wikipathways.org)
  • Bladder connexin43 levels and functional capacity show circadian oscillations in wild-type mice, but such rhythms are completely lost in Cry-null mice having a dysfunctional biological clock. (sigmaaldrich.com)
  • Disruption in circadian rhythms leads to increased incidence of many diseases, including metabolic disease and cancer. (nutritionreview.org)
  • This may explain, in part, why altered circadian rhythms in people who do shift work is associated with metabolic disorders. (nutritionreview.org)
  • The circadian clock orchestrates daily rhythms in metabolism, physiology and behaviour that allow organisms to anticipate regular changes in their environment, increasing their adaptation. (biomedcentral.com)
  • Such circadian phenotypes are underpinned by daily rhythms in gene expression. (biomedcentral.com)
  • An alternative strategy to existing assays is to use genomic microarrays to analyze circadian rhythms. (clinicaltrials.gov)
  • Establishing a molecular assay in humans for circadian rhythms from a single time point will allow us to identify circadian rhythm disorders, and to assess internal biological time to deliver therapies at their most efficacious time. (clinicaltrials.gov)
  • We will discuss the elaborate molecular mechanisms that allow circadian clocks to produce their daily rhythms and to synchronise them to its environment. (coursera.org)
  • Direct regulation of CLOCK expression by REV-ERB. (wikipathways.org)
  • Moreover, our results demonstrate that circadian alternative splicing is regulated by the interaction between distinct physiological cues, and illustrates the capability of single genes to integrate circadian signals at different levels of regulation. (biomedcentral.com)
  • However, an aspect of alternative splicing that is yet to be considered in mammals is its regulation by physiological systems such as the circadian clock. (biomedcentral.com)
  • Synchronized by light and darkness, the circadian clock exerts control over wake/sleep cycles, body temperature, digestion, hormonal cycles and other physiological and behavior patterns. (medindia.net)
  • But whether the circadian clock regulated aggressive behavior was unknown. (medindia.net)
  • Endogenous circadian clocks ensure that temporal patterns of physiology and behavior predict environmental changes determined by the Earth's rotation and orbit of the Sun. Such clocks are synchronized by the daily light-dark cycle. (phys.org)
  • A key question for circadian biologists concerns the way in which seasonal changes in day-length alter the behavior of circadian clocks over the course of the year. (phys.org)
  • The 24-hour internal clock controls many aspects of human behavior and physiology, including sleep, blood pressure, and metabolism. (nutritionreview.org)
  • The circadian or inner clock coordinates the sleep-wake rhythm and many other body processes that regulate, for example, metabolism, blood pressure, and the immune system. (phys.org)
  • We assume that the formation of this cryptochrome-period protein complex provides a mechanism by which the circadian clock interacts with the metabolism, while the zinc ion and the disulfide bond play an important role in regulating the stability of the complex," summarized Wolf. (phys.org)
  • These findings establish the Rev-erbs as major regulators of both clock function and metabolism. (nutritionreview.org)
  • Circadian rhythm of metabolism is important because disruption of this rhythm leads to a fatty liver. (nutritionreview.org)
  • The identification of circadian clocks in endocrine tissues has added considerable depth and complexity to our understanding of their physiology. (frontiersin.org)
  • Even given the evidence for a molecular clockwork in multiple cells of the uterus and data showing that the expression levels and/or amplitude of cycling clock genes are modulated by circulating steroids, a clear linkage to uterine physiology has yet to be clearly demonstrated. (frontiersin.org)
  • Identifying physiologically important downstream targets for circadian clock genes in the uterus has yet to be achieved, but research in this field promises to contribute new and important insights into normal and pathological uterine physiology. (frontiersin.org)
  • Circadian timekeeping is an essential biological process that influences most, if not all, aspects of eukaryotic and prokaryotic physiology. (biomedcentral.com)
  • Now, for the first time, a team of neuroscientists at Beth Israel Deaconess Medical Center (BIDMC) has demonstrated circadian control of aggression in male mice and identified the specific neurons and circuitry regulating the daily pattern. (medindia.net)
  • Next, the scientists used genetics-based tools to manipulate neurons known to regulate the central circadian clock. (medindia.net)
  • Using optogenetics, a technique that uses light to activate or deactivate targeted brain cells - to map brain circuitry revealed two parallel pathways between the biological clock and a population of neurons in a sub-region of the hypothalamus (called the VMHvl) known to cause violent attacks when stimulated in male mice. (medindia.net)
  • The suprachiasmatic nucleus (SCN) in the hypothalamus is the major clock in the body and receives its major input from light (via retinal neurons) and a minor input from nutrient intake. (wikipathways.org)
  • In the new work, published in this week's issue of Current Biology, Dr David Hazlerigg and colleagues considered the possibility that distinct populations of neurons within the principal mammalian circadian clock (the suprachiasmatic nuclei of the hypothalamus, SCN) might constitute these different oscillators. (phys.org)
  • The circadian clock regulates alternative splicing in a manner that is both tissue-dependent and concurrent with circadian transcript abundance. (biomedcentral.com)
  • Bladder muscle cells have an internal clock, and show oscillations of connexin43 and gap junction function. (sigmaaldrich.com)
  • Along with additional epigenetic and post-translational modification processes, core clock proteins within the suprachiasmatic nucleus serve to sustain the oscillations of peripheral clocks and rhythmic expression of downstream targets [ 7 ]. (biomedcentral.com)
  • the CRY and PER proteins then inhibit transactivation by BMAL1:CLOCK/NPAS2. (wikipathways.org)
  • Levels of PER and CRY proteins rise during the day and inhibit expression of CRY, PER, and other BMAL1:CLOCK/NPAS2-activated genes in the afternoon and evening. (wikipathways.org)
  • Human casein kinase Idelta phosphorylation of human circadian clock proteins period 1 and 2. (wikipathways.org)
  • Among the currently investigated topics are the cryptochromes, a class of proteins associated with the circadian clock in mammals. (phys.org)
  • The now Mainz-based biologist hopes that further findings about the basic functioning of the cryptochrome-period complex and her aim of determining the interaction patterns of further clock proteins may help in the development of future medical treatments. (phys.org)
  • The researchers found that autophagic digestion selectively targets proteins controlling the circadian clock, most notably the clock protein CRY1. (yu.edu)
  • A circadian oscillation can be reconstituted in vitro from three proteins that cycles with a period of ∼ 24 h. (vanderbilt.edu)
  • One of these proteins, called Rev-erb alpha, was thought to have a subordinate role because the clock runs fairly normally in its absence. (nutritionreview.org)
  • A research team led by Professor Eva Wolf, recently appointed Professor of Structural Biology at the Institute of General Botany of Johannes Gutenberg University Mainz (JGU) and Adjunct Director at the Institute of Molecular Biology (IMB), has for the first time identified the molecular structure of a protein complex that plays an important role in regulating the circadian rhythm. (phys.org)
  • hree-dimensional structure of the mouse cryptochrome-period clock protein complex. (phys.org)
  • Together with another clock protein called period they form a complex, the structure of which has just been determined by Wolf's team. (phys.org)
  • When they knocked out both Rev-erb alpha and Rev-erb beta, they saw a loss of the rhythmic cycling of the clock protein Bmal 1's messenger RNA. (nutritionreview.org)
  • This SNP results in the deletion of exon 19 in the clock gene and a 51 amino acid deletion in the CLOCK protein. (wordpress.com)
  • Furthermore, an analysis of circadian mutant Vipr2 -/- mice revealed the existence of distinct physiological pathways controlling circadian alternative splicing and RNA binding protein expression, with contrasting dependence on Vipr2-mediated physiological signals. (biomedcentral.com)
  • REV-ERBA shows strong circadian rhythmicity and confers circadian expression on BMAL1. (wikipathways.org)
  • Farmers are limited by the seasons, but by understanding the circadian rhythm of plants, which controls basic functions such as photosynthesis and flowering, we might be able to engineer plants that can grow in different seasons and places than is currently possible,' said Xing Wang Deng, the Daniel C. Eaton Professor of Molecular, Cellular, and Developmental Biology at Yale and senior author of the paper. (thcfarmer.com)
  • In a study published recently in BMC Biology a team from McGill University (Quebec, Canada), led by Nicolas Cermakain, have demonstrated for the first time that enhancing circadian clock function in a cancerous cells has an impact on tumor development. (oncology-central.com)
  • Therefore, circadian oscillation of connexin43 is associated with the biological clock and contributes to diurnal changes in bladder capacity, which avoids disturbance of sleep by micturition. (sigmaaldrich.com)
  • Activating the biological clock in tumors could become an innovative approach in slowing their growth or that of metastases. (oncology-central.com)
  • Here the investigators exploit our newfound understanding of clock mechanisms and the development of new genomic technologies to identify novel complements of clock-regulated genes ('signatures') that will reveal the state of the internal biological clock. (clinicaltrials.gov)
  • The material will be of interest to those who are pursuing a career in any of the life sciences as well as anyone who has run up against their biological clock. (coursera.org)
  • The body's circadian clock controls an early-evening agitation known as 'sundowning,' which is common in patients with Alzheimer's disease and dementia. (medindia.net)
  • The nuclear hormone receptors REV-ERBα and REV-ERBβ are essential components of the body's circadian clock. (acs.org)
  • The circadian clock is the internal timekeeper found in almost all organisms that helps synchronize biological processes with day and night. (thcfarmer.com)
  • The authors also found widespread expression of clock within several murine tissues and conserved clock gene sequences in other organisms, demonstrating the important function of this gene within the circadian system. (wordpress.com)
  • Over the past two decades, molecular geneticists have 'cracked' the clock to reveal its core biochemical mechanisms evident in organisms from fruit flies to humans. (clinicaltrials.gov)
  • Many studies in a number of organisms as well as multiple organs and tissues have found that substantial fractions of the genome (2-10%) are under robust circadian clock control. (clinicaltrials.gov)
  • A key study to draw attention to the potential role of the circadian clock and pregnancy was that of Miller et al (2004), who reported that pregnant mice lacking the functional Clock gene (ClockΔ19) had prolonged and non-productive parturition, suggestive of a role for circadian clocks in the parturition event. (frontiersin.org)
  • Numerous studies have since shed light on the role of the circadian clock in cancer development in humans. (biomedcentral.com)
  • Transcription of the BMAL1 (ARNTL) gene is controlled by ROR-alpha and REV-ERBA (NR1D1), both of which are targets of BMAL1:CLOCK/NPAS2 in mice and both of which compete for the same element (RORE) in the BMAL1 promoter. (wikipathways.org)
  • Genetic mapping and sequencing in mice confirmed the identification of the mammalian gene, clock , involved in the circadian system. (wordpress.com)
  • One idea for which evidence has accumulated is that circadian clocks contain coupled "morning" and "evening" oscillators that are separately synchronized to dawn and dusk. (phys.org)
  • These results could form the basis for new strategies for treating illnesses that are the result of circadian clock dysfunction. (phys.org)
  • These results are consistent with the idea that ovarian steroid levels during the estrous cycle have a modulating influence of clock gene expression in the uterus. (frontiersin.org)
  • The hub1-1 mutation reduced the amplitudes of a number of induced clock gene expression peaks, as well as the HUB1-mediated histone H2BUb and H3K4Me3 marks associated with the coding regions, suggesting a role for HUB1 in facilitating transcriptional elongation in plants. (ugent.be)
  • Yet the prevalence of circadian disruption in these patient populations is unclear because current tests are not easily applied in clinical settings or have yet to be developed. (clinicaltrials.gov)
  • This approach will allow us to take a genomic snapshot of clock status from a single blood draw, substantially easing the diagnosis of these individuals with evidence of circadian disruption or misalignment, i.e., chronopathology. (clinicaltrials.gov)
  • The development of an assay from a single blood draw would represent a major step forward, facilitating assessments of circadian disruption in a range of diseases. (clinicaltrials.gov)
  • BMAL1:CLOCK/NPAS2 activates transcription of CRY, PER, and several other genes in the morning. (wikipathways.org)
  • BMAL1 can form heterodimers with either CLOCK or NPAS2, which act redundantly but show different tissue specificity. (wikipathways.org)
  • The BMAL1:CLOCK and BMAL1:NPAS2 heterodimers activate a set of genes that possess E-box elements (consensus CACGTG) in their promoters. (wikipathways.org)
  • The PER genes (PER1, PER2, PER3) and CRY genes (CRY1, CRY2) are among those activated by BMAL1:CLOCK and BMAL1:NPAS2. (wikipathways.org)
  • Within the nucleus the PER:CRY complexes bind BMAL1:CLOCK and BMAL1:NPAS2, inhibiting their transactivation activity and their phosphorylation. (wikipathways.org)
  • This reduces expression of the target genes of BMAL1:CLOCK and BMAL1:NPAS2 during the afternoon and evening. (wikipathways.org)
  • CK2alpha phosphorylates BMAL1 to regulate the mammalian clock. (wikipathways.org)
  • CLOCK and BMAL1 heterodimerise and bind to E-box elements in PERs and CRYs to drive their rhythmic transcription [ 1 , 2 , 3 ]. (biomedcentral.com)
  • 2010) examined expression of circadian clock genes in the mouse uterus in late pregnancy and found significant daily mRNA variations ex vivo for some but not for all clock genes. (frontiersin.org)
  • As evidence continues to accumulate for the expression of circadian clocks in the various layers of the mammalian uterus, numerous questions arise as to the identity of the cues for entrainment of these peripheral clocks, the synchronizing mechanisms across the uterus, as well as downstream clock gene targets. (frontiersin.org)
  • This confers circadian expression on the genes. (wikipathways.org)
  • Here, we determined the effects of the hub1-1 mutation on expression of a set of diurnally induced circadian clock genes identified from a comparative microarray analysis between the hub1-1 mutant and an HUB1 over-expression line. (ugent.be)
  • The Yale research solved one of the last remaining mysteries in this process when they identified the gene DET1 as crucial in helping to suppress expression of the evening genes in the circadian cycle. (thcfarmer.com)
  • Feeding is an important circadian stimulus, and we found that fasting both modulates hepatic circadian alternative splicing in an exon-dependent manner and changes the temporal relationship with transcript-level expression. (biomedcentral.com)
  • Our circadian clocks are centered in the brain and control key physiological processes-sleep, body temperature, organ function, and metabolic activities such as maintaining blood glucose levels. (yu.edu)
  • The findings reinforced a connection researchers have observed between cancer and the circadian clock, a biological system that controls the daily schedule of physiological processes. (acs.org)
  • The circadian clock governs a large variety of fundamentally important physiological processes in all three domains of life. (biomedcentral.com)
  • Disrupting the clock can potentially lead to diabetes and other metabolic diseases. (yu.edu)
  • These mechanistic insights have led to the discovery of links between clock function and an ever-expanding array of prevalent diseases, including heart, lung, metabolic and sleep disorders. (clinicaltrials.gov)
  • This view was corroborated by the analysis of the effect of fasting on circadian alternative splicing. (biomedcentral.com)
  • CRY1 is a key regulator of circadian cycles and also helps maintain blood glucose levels by inhibiting the liver from forming and secreting glucose. (yu.edu)
  • Validated circadian exons were regulated in a tissue-dependent manner and were present in genes with circadian transcript abundance. (biomedcentral.com)
  • Circadian reprogramming of tumour genomes resulted in activation of numerous oncogenic pathways including those associated with cancer stem cells, suggesting that the circadian clock may influence self-renewal mechanisms. (biomedcentral.com)
  • A clock regulator, Rev-erbα, upregulates connexin43 transcription as a cofactor of Sp1, using Sp1 cis-elements of the promoter. (sigmaaldrich.com)
  • It can be speculated that various rhythmic events in the uterus depend on regulatory genes that are clock-driven, or that are under the control of circulating hormonal cues. (frontiersin.org)