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circadian phenotype

Yanzhu Lin, Zhen-Xia Chen, Brian Oliver, Susan T Harbison
Differences in phenotype among genetically identical individuals exposed to the same environmental condition are often noted in genetic studies. Despite this commonplace observation, little is known about the causes of this variability, which has been termed microenvironmental plasticity. One possibility is that stochastic or technical sources of variance produce these differences. A second possibility is that this variation has a genetic component. We have explored gene expression robustness in the transcriptomes of 730 individual Drosophila melanogaster of 16 fixed genotypes, 9 of which are infected with Wolbachia Three replicates of flies were grown controlling for food, day/night cycles, humidity, temperature, sex, mating status, social exposure, and circadian timing of RNA extraction...
October 21, 2016: G3: Genes—Genomes—Genetics
Joseph F O'Grady, Laura S Hoelters, Martin T Swain, David C Wilcockson
BACKGROUND: Talitrus saltator is an amphipod crustacean that inhabits the supralittoral zone on sandy beaches in the Northeast Atlantic and Mediterranean. T. saltator exhibits endogenous locomotor activity rhythms and time-compensated sun and moon orientation, both of which necessitate at least one chronometric mechanism. Whilst their behaviour is well studied, currently there are no descriptions of the underlying molecular components of a biological clock in this animal, and very few in other crustacean species...
2016: PeerJ
L Müller, D Weinert
In a natural environment, social abilities of an animal are important for its survival. Particularly, it must recognize its own social rank and the social rank of a conspecific and have a good social memory. While the role of the circadian system for object and spatial recognition and memory is well known, the impact of the social rank and circadian disruptions on social recognition and memory were not investigated so far. In the present study, individual recognition of social rank and social memory performance of Djungarian hamsters revealing different circadian phenotypes were investigated...
October 13, 2016: Behavioural Processes
Theresa L B Edelman, Katherine A McCulloch, Angela Barr, Christian Frøkjær-Jensen, Erik M Jorgensen, Ann E Rougvie
The Caenorhabditis elegans heterochronic gene pathway regulates the relative timing of events during post-embryonic development. lin-42, the worm homolog of the circadian clock gene period, is a critical element of this pathway. lin-42 function has been defined by a set of hypomorphic alleles that cause precocious phenotypes, in which later developmental events, such as the terminal differentiation of hypodermal cells, occur too early. A subset of alleles also reveals a significant role for lin-42 in molting; larval stages are lengthened and ecdysis often fails in these mutant animals...
October 14, 2016: G3: Genes—Genomes—Genetics
Na Liu, Eric Erquan Zhang
The core circadian oscillator in mammals is composed of transcription/translation feedback loop, in which cryptochrome (CRY) proteins play critical roles as repressors of their own gene expression. Although post-translational modifications, such as phosphorylation of CRY1, are crucial for circadian rhythm, little is known about how phosphorylated CRY1 contributes to the molecular clockwork. To address this, we created a series of CRY1 mutants with single amino acid substitutions at potential phosphorylation sites and performed a cell-based, phenotype-rescuing screen to identify mutants with aberrant rhythmicity in CRY-deficient cells...
2016: Frontiers in Neurology
Maija Mutikainen, Tomi Tuomainen, Nikolay Naumenko, Jenni Huusko, Boris Smirin, Svetlana Laidinen, Krista Kokki, Heidi Hynynen, Seppo Ylä-Herttuala, Merja Heinäniemi, Jorge L Ruas, Pasi Tavi
The transcriptional coactivator PGC-1α1 has been identified as a central factor mediating metabolic adaptations of the heart. However, it is still mostly unresolved how much physiological changes in PGC-1α1 expression levels actually contribute to the functional adaptation of the heart. The aim of this study was to characterize the transcriptional and functional effects of physiologically relevant, moderate PGC-1α1 expression in the heart. In vivo and ex vivo physiological analysis shows that expression of PGC-1α1 within a physiological range in mouse heart does not induce the expected metabolic alterations, but instead induces a unique E-C-coupling phenotype recapitulating features typically seen in physiological hypertrophy...
September 26, 2016: Journal of Physiology
Louise L Hansen, Gerben van Ooijen
The plant circadian clock allows the anticipation of daily changes to the environment. This anticipation aids the responses to temporally predictable biotic and abiotic stress. Conversely, disruption of circadian timekeeping severely compromises plant health and reduces agricultural crop yields. It is therefore imperative that we understand the intricate regulation of circadian rhythms in plants, including the factors that affect motion of the transcriptional clockwork itself. Testing circadian defects in the model plant Arabidopsis thaliana (Arabidopsis) traditionally involves crossing specific mutant lines to a line rhythmically expressing firefly luciferase from a circadian clock gene promoter...
2016: Journal of Visualized Experiments: JoVE
Basile Lebailly, Francina Langa, Christian Boitard, Philip Avner, Ute Christine Rogner
Nonobese diabetic (NOD) mice are a model for type 1 diabetes that displays defects in central immune tolerance, including impairment of thymocyte apoptosis and proliferation. Thymocyte apoptosis is decreased in NOD/Lt mice compared to nondiabetic C3H/HeJ and C57BL/6 mice. Analysis of a set of NOD.C3H and NOD.B6 congenic mouse strains for distal chromosome 6 localizes the phenotype to the 700 kb Idd6.3 interval. Idd6.3 contains the type 1 diabetes candidate gene aryl hydrocarbon receptor nuclear translocator-like 2 (Arntl2), encoding a circadian rhythm-related transcription factor...
September 26, 2016: Mammalian Genome: Official Journal of the International Mammalian Genome Society
Vaishnavi Jadhav, Qianyi Luo, James M Dominguez, Jude Al-Sabah, Brahim Chaqour, Maria B Grant, Ashay D Bhatwadekar
Period 2-mutant mice (Per2m/m), which possess a circadian dysfunction, recapitulate the retinal vascular phenotype similar to diabetic retinopathy (DR). The vascular dysfunction in Per2m/m is associated with an increase in connective tissue growth factor (CTGF/CCN2). At the molecular level, CTGF gene expression is dependent on the canonical Wnt/β-catenin pathway. The nuclear binding of β-catenin to a transcription factor, lymphoid enhancer binding protein (Lef)/ T-cell factor (TCF/LEF), leads to downstream activation of CTGF...
2016: PloS One
Hye-Min Song, Chul-Hyun Cho, Heon-Jeong Lee, Joung Ho Moon, Seung-Gul Kang, Ho-Kyoung Yoon, Young-Min Park, Leen Kim
Polymorphisms in human circadian genes are potential genetic markers that affect diurnal preference in several populations. In this study, we evaluated whether four polymorphisms in circadian genes CLOCK, ARNTL, PER2, and GNB3 were associated with diurnal preference in a Korean population. In all, 499 healthy subjects were genotyped for four functional polymorphisms in CLOCK, ARNTL, PER2, and GNB3. Composite scale of morningness (CSM) was applied to measure phenotype patterns of human diurnal preference. In addition, three subscale scores, i...
September 23, 2016: Chronobiology International
Koliane Ouk, Juliet Aungier, A Jennifer Morton
Huntington's disease (HD) is a progressive genetic neurodegenerative disorder characterised by motor and cognitive deficits, as well as sleep and circadian abnormalities. In the R6/2 mouse, a fragment model of HD, rest-activity rhythms controlled by the suprachiasmatic nucleus disintegrate completely by 4months of age. Rhythms driven by a second circadian oscillator, the methamphetamine-sensitive circadian oscillator (MASCO), are disrupted even earlier, and cannot be induced after 2months of age. Here, we studied the effect of the HD mutation on the expression of MASCO-driven rhythms in a more slowly developing, genetically relevant mouse model of HD, the Q175 'knock-in' mouse...
September 16, 2016: Experimental Neurology
Alexandra Vaccaro, Serge Birman, André Klarsfeld
Endogenous circadian clocks with ~24-h periodicity are found in most organisms from cyanobacteria to humans. Daylight synchronizes these clocks to solar time. In humans, shift-work and jet lag perturb clock synchronization, and such perturbations, when repeated or chronic, are strongly suspected to be detrimental to healthspan. Here we investigated locomotor aging and longevity in Drosophila melanogaster with genetically or environmentally disrupted clocks. We compared two mutations in period (per, a gene essential for circadian rhythmicity in Drosophila), after introducing them in a common reference genetic background: the arrhythmic per(01), and per(T) which displays robust short 16-h rhythms...
September 14, 2016: Experimental Gerontology
K Solocinski, M Holzworth, X Wen, K-Y Cheng, I J Lynch, B D Cain, C S Wingo, M L Gumz
AIM: Increasing evidence demonstrates that circadian clock proteins are important regulators of physiological functions including blood pressure. An established risk factor for developing cardiovascular disease is the absence of a blood pressure dip during the inactive period. The goal of the present study was to determine the effects of a high salt diet plus mineralocorticoid on PER1-mediated blood pressure regulation in a salt-resistant, normotensive mouse model, C57BL/6J. METHODS: Blood pressure was measured using radiotelemetry...
September 16, 2016: Acta Physiologica
Carine M Marshall, Virginia Tartaglio, Maritza Duarte, Frank G Harmon
The circadian clock allows plants to anticipate and respond to daily changes in ambient temperature. Mechanisms establishing the timing of circadian rhythms in Arabidopsis thaliana through temperature entrainment remain unclear. Also incompletely understood is the temperature compensation mechanism that maintains consistent period length within a range of ambient temperatures. A genetic screen for Arabidopsis mutants affecting temperature regulation of the PSEUDO-RESPONSE REGULATOR7 promoter yielded a novel allele of the SICKLE (SIC) gene...
September 13, 2016: Plant Cell
Q S Li, C Tian, G R Seabrook, W C Drevets, V A Narayan
Genetic predisposition may contribute to the differences in drug-specific, class-specific or antidepressant-wide treatment resistance. Clinical studies with the genetic data are often limited in sample sizes. Drug response obtained from self-reports may offer an alternative approach to conduct a study with much larger sample size. Using the phenotype data collected from 23andMe 'Antidepressant Efficacy and Side Effects' survey and genotype data from 23andMe's research participants, we conducted genome-wide association study (GWAS) on subjects of European ancestry using four groups of phenotypes (a) non-treatment-resistant depression (n=7795) vs treatment-resistant depression (TRD, n=1311), (b) selective serotonin reuptake inhibitors (SSRI) responders (n=6348) vs non-responders (n=3340), (c) citalopram/escitalopram responders (n=2963) vs non-responders (n=2005), and (d) norepinephrine-dopamine reuptake inhibitor (NDRI, bupropion) responders (n=2675) vs non-responders (n=1861)...
2016: Translational Psychiatry
Yang-Hong Zhou, Zhong-Wei Zhang, Chong Zheng, Shu Yuan, Yikun He
The delayed flowering phenotype caused by nitrogen (N) fertilizer application has been known for a long time, but we know little about the specific molecular mechanism for this phenomenon before. Our study indicated that low nitrogen increases the NADPH/NADP(+) and ATP/AMP ratios which affect adenosine monophosphate-activated protein kinase (AMPK) activity and phosphorylation and abundance of nuclear CRY1 protein. Then CRY1 acts in the N signal input pathway to the circadian clock. Here we further discuss: (1) the role of C/N ratio in flowering, (2) circadian oscillation of plant AMPK transcripts and proteins, (3) conservation of nutrition-mediated CRY1 phosphorylation and degradation, and (4) crosstalks between nitrogen signals and nitric oxide (NO) signals in flowering...
September 2016: Plant Signaling & Behavior
Xiangqian Zhang, Xu Zheng, Shanwen Ke, Haitao Zhu, Fang Liu, Zemin Zhang, Xinxiang Peng, Lin Guo, Ruizhen Zeng, Pei Hou, Ziqiang Liu, Suowei Wu, Meifang Song, Jianping Yang, Guiquan Zhang
Most environmental perturbations have a direct or indirect deleterious impact on photosynthesis, and, in consequence, the overall energy status of the cell. Despite our increased understanding of convergent energy and stress signals, the connections between photosynthesis, energy and stress signals through putative common nodes are still unclear. Here we identified an endoplasmic reticulum (ER)-localized adenine nucleotide transporter1 (ER-ANT1), whose deficiency causes seedling lethality in air but viable under high CO2, exhibiting the typical photorespiratory phenotype...
September 10, 2016: Plant Molecular Biology
K Kario
Out-of-office blood pressure (BP) measured by home BP monitoring, or ambulatory BP monitoring, was demonstrated to be superior to office BP for the prediction of cardiovascular events. The J-HOP study of a nationwide Japanese cohort demonstrated that morning home BP is the best stroke predictor. In the prospective HONEST study of >21 000 hypertensives, on-treatment morning home BP was shown to be a strong predictor both of future coronary artery disease and stroke events. In subjects whose office BP was maintained at ⩾150 mm Hg, there was no increase in cardiovascular events when their morning systolic BP was well-controlled at <125 mm Hg...
September 8, 2016: Journal of Human Hypertension
Georgia Coleman, John Gigg, Maria Mercè Canal
The postnatal light environment that a mouse experiences during the critical first 3 postnatal weeks has long-term effects on both its circadian rhythm output and clock gene expression. Furthermore, data from our lab suggest that postnatal light may also impact the hypothalamic-pituitary-adrenal (HPA) axis, which is a key regulator of stress. To test the effect of postnatal light exposure on adult stress responses and circadian rhythmicity, we raised mice under either 24-h light-dark cycles (LD), constant light (LL) or constant dark (DD) during the first 3 postnatal weeks...
September 3, 2016: European Journal of Neuroscience
M Liu, K-C Yang, S C Dudley
The cardiac Na(+) channel (Nav1.5) conducts a depolarizing inward Na(+) current that is responsible for the generation of the upstroke Phase 0 of the action potential. In heart tissue, changes in Na(+) currents can affect conduction velocity and impulse propagation. The cardiac Nav1.5 is also involved in determination of the action potential duration, since some channels may reopen during the plateau phase, generating a persistent or late inward current. Mutations of cardiac Nav1.5 can induce gain or loss of channel function because of an increased late current or a decrease of peak current, respectively...
2016: Current Topics in Membranes
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