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Pfeffer M, von Gall C, Wicht H, Korf HW. The Role of the Melatoninergic System in Circadian and Seasonal Rhythms—Insights From Different Mouse Strains. Front Physiol 2022; 13:883637. [PMID: 35492605 PMCID: PMC9039042 DOI: 10.3389/fphys.2022.883637] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 03/22/2022] [Indexed: 01/01/2023] Open
Abstract
The melatoninergic system comprises the neurohormone melatonin and its molecular targets. The major source of melatonin is the pineal organ where melatonin is rhythmically produced during darkness. In mammals, melatonin biosynthesis is controlled by the central circadian rhythm generator in the suprachiasmatic nucleus (SCN) and photoreceptors in the retina. Melatonin elicits its function principally through two specific receptors called MT1 and MT2. MT1 is highly expressed in the SCN and the hypophysial pars tuberalis (PT), an important interface for control of seasonal functions. The expression of the MT2 is more widespread. The role of the melatoninergic system in the control of seasonal functions, such as reproduction, has been known for more than 4 decades, but investigations on its impact on the circadian system under normal (entrained) conditions started 2 decades later by comparing mouse strains with a fully functional melatoninergic system with mouse strains which either produce insufficient amounts of melatonin or lack the melatonin receptors MT1 and MT2. These studies revealed that an intact melatoninergic system is not required for the generation or maintenance of rhythmic behavior under physiological entrained conditions. As shown by jet lag experiments, the melatoninergic system facilitated faster re-entrainment of locomotor activity accompanied by a more rapid adaptation of the molecular clock work in the SCN. This action depended on MT2. Further studies indicated that the endogenous melatoninergic system stabilizes the locomotor activity under entrained conditions. Notably, these effects of the endogenous melatoninergic system are subtle, suggesting that other signals such as corticosterone or temperature contribute to the synchronization of locomotor activity. Outdoor experiments lasting for a whole year indicate a seasonal plasticity of the chronotype which depends on the melatoninergic system. The comparison between mice with an intact or a compromised melatoninergic system also points toward an impact of this system on sleep, memory and metabolism.
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Affiliation(s)
- Martina Pfeffer
- Institute of Anatomy II, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
- *Correspondence: Martina Pfeffer,
| | - Charlotte von Gall
- Institute of Anatomy II, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
| | - Helmut Wicht
- Dr. Senckenbergische Anatomie II, Fachbereich Medizin der Goethe-Universität, Frankfurt am Main, Germany
| | - Horst-Werner Korf
- Institute of Anatomy I, Medical Faculty, Heinrich Heine University, Düsseldorf, Germany
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Pfeffer M, Korf HW, Wicht H. Synchronizing effects of melatonin on diurnal and circadian rhythms. Gen Comp Endocrinol 2018; 258:215-221. [PMID: 28533170 DOI: 10.1016/j.ygcen.2017.05.013] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 04/27/2017] [Accepted: 05/16/2017] [Indexed: 01/02/2023]
Abstract
In mammals, the rhythmic secretion of melatonin from the pineal gland is driven by the circadian clock in the suprachiasmatic nucleus (SCN) of the hypothalamus. The robust nightly peak of melatonin secretion is an output signal of the circadian clock and is supposed to deliver the circadian message to the whole of the organism. Since the circadian system regulates many behavioral and physiological processes, its disruption by external (shift-work, jet-lag) or internal desynchronization (blindness, aging) causes many different health problems. Externally applied melatonin is used in humans as a chronobiotic drug to treat desynchronization and circadian disorders, and the success of these treatments does, at first glance, underline the supposed pivotal role of melatonin in the synchronization of the circadian system. On the other hand, pinealectomy in experimental animals and humans does not abolish their rhythms of rest and activity. Furthermore, mice with deficient melatoninergic systems neither display overt defects in their rhythmic behavior nor do they show obvious signs of disease susceptibility, let alone premature mortality. During the last years, our laboratory has investigated several mouse stains with intact or compromised internal melatonin signaling systems in order to better understand the physiological role of the melatoninergic system. These and other investigations which will be reviewed in the present contribution confirm the synchronizing effect of endogenous melatonin and the melatoninergic system. However, these effects are subtle. Thus melatonin does not appear as the master of internal synchronization, but as one component in a cocktail of synchronizing agents.
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Affiliation(s)
- Martina Pfeffer
- Dr. Senckenbergische Anatomie II, Fachbereich Medizin, Goethe-Universität Frankfurt, Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany; Dr. Senckenbergisches Chronomedizinisches Institut, Goethe-Universität Frankfurt, Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany.
| | - Horst-Werner Korf
- Dr. Senckenbergische Anatomie II, Fachbereich Medizin, Goethe-Universität Frankfurt, Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany; Dr. Senckenbergisches Chronomedizinisches Institut, Goethe-Universität Frankfurt, Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany
| | - Helmut Wicht
- Dr. Senckenbergische Anatomie II, Fachbereich Medizin, Goethe-Universität Frankfurt, Theodor-Stern-Kai 7, D-60590 Frankfurt am Main, Germany
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Peirson SN, Brown LA, Pothecary CA, Benson LA, Fisk AS. Light and the laboratory mouse. J Neurosci Methods 2017; 300:26-36. [PMID: 28414048 PMCID: PMC5909038 DOI: 10.1016/j.jneumeth.2017.04.007] [Citation(s) in RCA: 117] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Revised: 04/10/2017] [Accepted: 04/11/2017] [Indexed: 02/06/2023]
Abstract
Light exerts widespread effects on physiology and behaviour. As well as the widely-appreciated role of light in vision, light also plays a critical role in many non-visual responses, including regulating circadian rhythms, sleep, pupil constriction, heart rate, hormone release and learning and memory. In mammals, responses to light are all mediated via retinal photoreceptors, including the classical rods and cones involved in vision as well as the recently identified melanopsin-expressing photoreceptive retinal ganglion cells (pRGCs). Understanding the effects of light on the laboratory mouse therefore depends upon an appreciation of the physiology of these retinal photoreceptors, including their differing sens itivities to absolute light levels and wavelengths. The signals from these photoreceptors are often integrated, with different responses involving distinct retinal projections, making generalisations challenging. Furthermore, many commonly used laboratory mouse strains carry mutations that affect visual or non-visual physiology, ranging from inherited retinal degeneration to genetic differences in sleep and circadian rhythms. Here we provide an overview of the visual and non-visual systems before discussing practical considerations for the use of light for researchers and animal facility staff working with laboratory mice.
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Affiliation(s)
- Stuart N Peirson
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford Molecular Pathology Institute, Dunn School of Pathology, South Parks Road, Oxford, United Kingdom.
| | - Laurence A Brown
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford Molecular Pathology Institute, Dunn School of Pathology, South Parks Road, Oxford, United Kingdom
| | - Carina A Pothecary
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford Molecular Pathology Institute, Dunn School of Pathology, South Parks Road, Oxford, United Kingdom
| | - Lindsay A Benson
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford Molecular Pathology Institute, Dunn School of Pathology, South Parks Road, Oxford, United Kingdom
| | - Angus S Fisk
- Sleep and Circadian Neuroscience Institute (SCNi), Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford Molecular Pathology Institute, Dunn School of Pathology, South Parks Road, Oxford, United Kingdom
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Anselmi M, Correa FJ, Santos JR, Silva AF, Cunha JA, Leão AHF, Campêlo CLC, Ribeiro AM, Silva RH, Izídio GS. Genetic evidence for chromosome 4 loci influencing learning and memory. Neurobiol Learn Mem 2016; 131:182-91. [PMID: 27044679 DOI: 10.1016/j.nlm.2016.03.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Revised: 03/21/2016] [Accepted: 03/30/2016] [Indexed: 10/22/2022]
Abstract
The Lewis (LEW) and SHR (Spontaneously Hypertensive Rats) inbred rat strains differ in several anxiety/emotionality and learning/memory-related behaviors. We aimed to search quantitative trait locus (QTL) that influence these behaviors and confirm their effects in a congenic rat strain SLA16 (SHR.LEW.Anxrr16). LEW females and SHR males were intercrossed to produce F2 rats (96/sex), which were all tested in the plus-maze discriminative avoidance task (PMDAT), open-field (OF), object recognition (OR), spontaneous alternation (SA) and fear conditioning (FC). All animals were genotyped for microsatellite markers located on chromosome (Chr) 4. Behavioral and genotypic data were used to perform factor and QTL analyses. Also, to confirm the QTL effects, we tested male and female SLA16 rats and their isogenic control SHR in the same behavioral tests. A factor analysis of the F2 population revealed a correlation between anxiety/emotionality related behaviors and learning/memory in both sexes. QTL analysis revealed two significant QTL in males and three in females, on behavioral parameters in the PMDAT, OF and FC. Four QTL found herein were confirmed in SLA16 rats. The SLA16 strain displayed lower levels of anxiety/emotionality, higher locomotor activity and deficits in learning/memory in comparison with SHR strain. The Chr 4 contains genes influencing anxiety/emotionality and learning/memory behaviors and the SLA16 strain represents a valuable tool in the search for them. The use of the SLA16 strain as a genetic model for studying behavioral phenomena and their implications for psychiatric disorders are discussed.
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Affiliation(s)
- Mayara Anselmi
- Laboratório de Genética do Comportamento, Departamento de Biologia Celular, Embriologia e Genética, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Fernanda Junkes Correa
- Laboratório de Genética do Comportamento, Departamento de Biologia Celular, Embriologia e Genética, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - José Ronaldo Santos
- Laboratório de Estudo da Memória em Roedores, Departamento de Fisiologia, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil; Laboratório de Neurociências, Departamento de Biociências, Universidade Federal de Sergipe, Itabaiana, SE, Brazil
| | - Anatildes Feitosa Silva
- Laboratório de Estudo da Memória em Roedores, Departamento de Fisiologia, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil
| | - João Antônio Cunha
- Laboratório de Estudo da Memória em Roedores, Departamento de Fisiologia, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil
| | - Anderson Henrique Figueiredo Leão
- Laboratório de Estudo da Memória em Roedores, Departamento de Fisiologia, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil; Laboratório de Neurociência Comportamental, Departamento de Farmacologia, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Clarissa Loureiro Chagas Campêlo
- Laboratório de Estudo da Memória em Roedores, Departamento de Fisiologia, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil
| | - Alessandra Mussi Ribeiro
- Laboratório de Estudo da Memória em Roedores, Departamento de Fisiologia, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil; Laboratório de Neurociências e Bioprospecção de Produtos Naturais, Departamento de Biociências, Universidade Federal de São Paulo, Santos, SP, Brazil
| | - Regina Helena Silva
- Laboratório de Estudo da Memória em Roedores, Departamento de Fisiologia, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil; Laboratório de Neurociência Comportamental, Departamento de Farmacologia, Universidade Federal de São Paulo, São Paulo, SP, Brazil
| | - Geison Souza Izídio
- Laboratório de Genética do Comportamento, Departamento de Biologia Celular, Embriologia e Genética, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil; Laboratório de Estudo da Memória em Roedores, Departamento de Fisiologia, Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil.
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Pfeffer M, Wicht H, von Gall C, Korf HW. Owls and larks in mice. Front Neurol 2015; 6:101. [PMID: 26029157 PMCID: PMC4432671 DOI: 10.3389/fneur.2015.00101] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 04/24/2015] [Indexed: 11/13/2022] Open
Abstract
Humans come in different chronotypes and, particularly, the late chronotype (the so-called owl) has been shown to be associated with several health risks. A number of studies show that laboratory mice also display various chronotypes. In mice as well as in humans, the chronotype shows correlations with the period length and rhythm stability. In addition, some mouse models for human diseases show alterations in their chronotypic behavior, which are comparable to those humans. Thus, analysis of the behavior of mice is a powerful tool to unravel the molecular and genetic background of the chronotype and the prevalence of risks and diseases that are associated with it. In this review, we summarize the correlation of chronotype with free-running period length and rhythm stability in inbred mouse strains, in mice with a compromised molecular clockwork, and in a mouse model for neurodegeneration.
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Affiliation(s)
- Martina Pfeffer
- Dr. Senckenbergische Anatomie II, Fachbereich Medizin der Goethe-Universität , Frankfurt am Main , Germany ; Dr. Senckenbergisches Chronomedizinisches Institut, Fachbereich Medizin der Goethe-Universität , Frankfurt am Main , Germany
| | - Helmut Wicht
- Dr. Senckenbergische Anatomie II, Fachbereich Medizin der Goethe-Universität , Frankfurt am Main , Germany ; Dr. Senckenbergisches Chronomedizinisches Institut, Fachbereich Medizin der Goethe-Universität , Frankfurt am Main , Germany
| | - Charlotte von Gall
- Institut für Anatomie II, Fachbereich Medizin, Heinrich Heine Universität , Düsseldorf , Germany
| | - Horst-Werner Korf
- Dr. Senckenbergische Anatomie II, Fachbereich Medizin der Goethe-Universität , Frankfurt am Main , Germany ; Dr. Senckenbergisches Chronomedizinisches Institut, Fachbereich Medizin der Goethe-Universität , Frankfurt am Main , Germany
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McCulley WD, Ascheid S, Crabbe JC, Rosenwasser AM. Selective breeding for ethanol-related traits alters circadian phenotype. Alcohol 2013; 47:187-94. [PMID: 23414725 DOI: 10.1016/j.alcohol.2013.01.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Revised: 01/10/2013] [Accepted: 01/12/2013] [Indexed: 10/27/2022]
Abstract
Previous studies in mice and rats have shown that selective breeding for high and low ethanol preference results in divergence of circadian phenotype in the selected lines. These results indicate that some alleles influencing ethanol preference also contribute to circadian rhythm regulation. Selective breeding has also been used to produce lines of mice differing in a number of other ethanol-related traits, while studies of phenotypic and genetic correlation indicate that diverse ethanol-related traits are influenced by both shared and unshared genetics. In the present study, we examined several features of circadian activity rhythms in a mouse line selected for binge-like drinking and in mouse lines selected for high and low severity of ethanol withdrawal convulsions. Specifically, Experiment 1 compared High Drinking in the Dark (HDID-1) mice to their genetically heterogeneous progenitor line (HS/Npt), and Experiment 2 compared Withdrawal Seizure-Prone (WSP-2) and Withdrawal Seizure-Resistant (WSR-2) mice. Both line pairs displayed differences in their daily activity patterns under light-dark conditions. In addition, HDID-1 mice showed shorter free-running periods in constant light and less coherent activity rhythms across lighting conditions relative to HS/Npt controls, while WSP-2 mice showed longer free-running periods in constant darkness relative to WSR-2 mice. These results strengthen the evidence for genetic linkages between responsiveness to ethanol and circadian regulation, and extend this evidence to include ethanol-related phenotypes other than preference drinking. However, the present results also indicate that the nature of genetic correlations between and within phenotypic domains is highly complex.
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Identifying predictors of activity based anorexia susceptibility in diverse genetic rodent populations. PLoS One 2012; 7:e50453. [PMID: 23226287 PMCID: PMC3511580 DOI: 10.1371/journal.pone.0050453] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2012] [Accepted: 10/22/2012] [Indexed: 11/19/2022] Open
Abstract
Animal studies are very useful in detection of early disease indicators and in unravelling the pathophysiological processes underlying core psychiatric disorder phenotypes. Early indicators are critical for preventive and efficient treatment of progressive psychiatric disorders like anorexia nervosa. Comparable to physical hyperactivity observed in anorexia nervosa patients, in the activity-based anorexia rodent model, mice and rats express paradoxical high voluntary wheel running activity levels when food restricted. Eleven inbred mouse strains and outbred Wistar WU rats were exposed to the activity-based anorexia model in search of identifying susceptibility predictors. Body weight, food intake and wheel running activity levels of each individual mouse and rat were measured. Mouse strains and rats with high wheel running activity levels during food restriction exhibited accelerated body weight loss. Linear mixed models for repeated measures analysis showed that baseline wheel running activity levels preceding the scheduled food restriction phase strongly predicted activity-based anorexia susceptibility (mice: Beta = −0.0158 (±0.003 SE), P<0.0001; rats: Beta = −0.0242 (±0.004 SE), P<0.0001) compared to other baseline parameters. These results suggest that physical activity levels play an important role in activity-based anorexia susceptibility in different rodent species with genetically diverse background. These findings support previous retrospective studies on physical activity levels in anorexia nervosa patients and indicate that pre-morbid physical activity levels could reflect an early indicator for disease severity.
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HTreeQA: Using Semi-Perfect Phylogeny Trees in Quantitative Trait Loci Study on Genotype Data. G3-GENES GENOMES GENETICS 2012; 2:175-89. [PMID: 22384396 PMCID: PMC3284325 DOI: 10.1534/g3.111.001768] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/01/2011] [Accepted: 10/22/2011] [Indexed: 01/30/2023]
Abstract
With the advances in high-throughput genotyping technology, the study of quantitative trait loci (QTL) has emerged as a promising tool to understand the genetic basis of complex traits. Methodology development for the study of QTL recently has attracted significant research attention. Local phylogeny-based methods have been demonstrated to be powerful tools for uncovering significant associations between phenotypes and single-nucleotide polymorphism markers. However, most existing methods are designed for homozygous genotypes, and a separate haplotype reconstruction step is often needed to resolve heterozygous genotypes. This approach has limited power to detect nonadditive genetic effects and imposes an extensive computational burden. In this article, we propose a new method, HTreeQA, that uses a tristate semi-perfect phylogeny tree to approximate the perfect phylogeny used in existing methods. The semi-perfect phylogeny trees are used as high-level markers for association study. HTreeQA uses the genotype data as direct input without phasing. HTreeQA can handle complex local population structures. It is suitable for QTL mapping on any mouse populations, including the incipient Collaborative Cross lines. Applied HTreeQA, significant QTLs are found for two phenotypes of the PreCC lines, white head spot and running distance at day 5/6. These findings are consistent with known genes and QTL discovered in independent studies. Simulation studies under three different genetic models show that HTreeQA can detect a wider range of genetic effects and is more efficient than existing phylogeny-based approaches. We also provide rigorous theoretical analysis to show that HTreeQA has a lower error rate than alternative methods.
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Umemori J, Nishi A, Lionikas A, Sakaguchi T, Kuriki S, Blizard DA, Koide T. QTL analyses of temporal and intensity components of home-cage activity in KJR and C57BL/6J strains. BMC Genet 2009; 10:40. [PMID: 19638241 PMCID: PMC2723135 DOI: 10.1186/1471-2156-10-40] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2008] [Accepted: 07/29/2009] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND A variety of mouse strains exhibit diversity in spontaneous activity consistent with an important genetic contribution. To date, many studies have defined spontaneous home-cage activity as total distance or total counts of activity within a test period. However, spontaneous activity is, in fact, a composite of elements of 'temporal' and 'intensity' that is similar to 'velocity'. Here, we report on quantitative trait loci for different components of spontaneous activity, an important step towards dissection of the underlying genetic mechanisms. RESULTS In the analysis of total home-cage activity (THA) after habituation in female mice, KJR strain exhibit higher activity than C57BL/6J (B6). In this study, THA was partitioned into two components: active time (AT) was an index of the 'temporal element' of THA, average activity during active time (AA) was an index of 'intensity'. Correlation analysis using B6xKJR F2 female mice indicated that AA is a major component of THA, whereas AA and AT were associated to a lesser degree. To explore the genetic basis of the activity differences, we conducted quantitative trait loci (QTL) analysis on data of THA and its components, AT and AA. Three significant QTL affecting variation of different components of home cage activity were identified, two linked QTL Hylaq1 and Hylaq2 on Chr 2, and Hylaq3 on Chr 10. Chromosomal positions of these QTL were previously implicated in locomotor activity (Chr 2) or open-field ambulation (Chr 10). The results indicated that Hylaq1 influences AT, Hylaq2, AA, while Hylaq3 is associated with both AA and AT. CONCLUSION Through this study, we found that variation in total home cage activity over a 3 day period is affected by variation in active time and intensity of activity. The latter two variables are distinct components of home cage activity with only partially overlapping genetic architecture.
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Affiliation(s)
- Juzoh Umemori
- Mouse Genomics Resource Laboratory, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
- Department of Genetics, The Graduate University for Advanced Studies (SOKENDAI), Hayama, Kanagawa, Japan
| | - Akinori Nishi
- Mouse Genomics Resource Laboratory, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
- Department of Genetics, The Graduate University for Advanced Studies (SOKENDAI), Hayama, Kanagawa, Japan
| | - Arimantas Lionikas
- School of Medical Sciences, College of Life Sciences and Medicine, University of Aberdeen, Aberdeen, UK
- Center for Developmental and Health Genetics, Pennsylvania State University, PA, USA
| | - Takayuki Sakaguchi
- Department of Mathematical Analysis and Statistical Inference; Statistical Genome Diversity Research Group, Prediction and Knowledge Discovery Research Center, The Institute of Statistical Mathematics, Tokyo, Japan
| | - Satoshi Kuriki
- Department of Mathematical Analysis and Statistical Inference; Statistical Genome Diversity Research Group, Prediction and Knowledge Discovery Research Center, The Institute of Statistical Mathematics, Tokyo, Japan
| | - David A Blizard
- Center for Developmental and Health Genetics, Pennsylvania State University, PA, USA
| | - Tsuyoshi Koide
- Mouse Genomics Resource Laboratory, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
- Department of Genetics, The Graduate University for Advanced Studies (SOKENDAI), Hayama, Kanagawa, Japan
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Watanabe T, Suzuki T, Ishikawa A, Yokota Y, Ueda HR, Yamada RG, Tei H, Imai S, Tomida S, Kobayashi J, Naito E, Yasuo S, Nakao N, Namikawa T, Yoshimura T, Ebihara S. Genetic and molecular analysis of wild-derived arrhythmic mice. PLoS One 2009; 4:e4301. [PMID: 19173005 PMCID: PMC2628734 DOI: 10.1371/journal.pone.0004301] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2008] [Accepted: 12/03/2008] [Indexed: 11/18/2022] Open
Abstract
A new circadian variant was isolated by screening the intercross offspring of wild-caught mice (Mus musculus castaneus). This variant was characterized by an initial maintenance of damped oscillations and subsequent loss of rhythmicity after being transferred from light-dark (LD) cycles to constant darkness (DD). To map the genes responsible for the persistence of rhythmicity (circadian ratio) and the length of free-running period (tau), quantitative trait locus (QTL) analysis was performed using F(2) mice obtained from an F(1) cross between the circadian variant and C57BL/6J mice. As a result, a significant QTL with a main effect for circadian ratio (Arrhythmicity; Arrh-1) was mapped on Chromosome (Chr) 8. For tau, four significant QTLs, Short free-running period (Sfp-1) (Chr 1), Sfp-2 (Chr 6), Sfp-3 (Chr 8), Sfp-4 (Chr 11) were determined. An epistatic interaction was detected between Chr 3 (Arrh-2) and Chr 5 (Arrh-3). An in situ hybridization study of clock genes and mouse Period1::luciferase (mPer1::luc) real-time monitoring analysis in the suprachiasmatic nucleus (SCN) suggested that arrhythmicity in this variant might not be attributed to core circadian mechanisms in the SCN neurons. Our strategy using wild-derived variant mice may provide a novel opportunity to evaluate circadian and its related disorders in human that arise from the interaction between multiple variant genes.
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Affiliation(s)
- Tsuyoshi Watanabe
- Division of Biomodeling, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Tohru Suzuki
- Division of Biomodeling, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
- Department of Infectious Disease, Hamamatsu University School of Medicine, Hamamatsu, Japan
| | - Akira Ishikawa
- Division of Applied Genetics and Physiology, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Yuki Yokota
- Division of Biomodeling, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Hiroki R. Ueda
- Laboratory for Systems Biology, Center for Developmental Biology, RIKEN, Hyogo, Japan
- Functional Genomics Subunit, Center for Developmental Biology, RIKEN, Hyogo, Japan
| | - Rikuhiro G. Yamada
- Laboratory for Systems Biology, Center for Developmental Biology, RIKEN, Hyogo, Japan
| | - Hajime Tei
- Research Group of Chronogenomics, Mitsubishi Kagaku Institute of Life Sciences, Tokyo, Japan
| | - Saki Imai
- Division of Biomodeling, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Shigeru Tomida
- Division of Biomodeling, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Junya Kobayashi
- Division of Biomodeling, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Emiko Naito
- Division of Biomodeling, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Shinobu Yasuo
- Division of Biomodeling, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Nobuhiro Nakao
- Division of Biomodeling, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Takao Namikawa
- Division of Applied Genetics and Physiology, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Takashi Yoshimura
- Division of Biomodeling, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Shizufumi Ebihara
- Division of Biomodeling, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
- * E-mail: .
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Barnard AR, Nolan PM. When clocks go bad: neurobehavioural consequences of disrupted circadian timing. PLoS Genet 2008; 4:e1000040. [PMID: 18516223 PMCID: PMC2295261 DOI: 10.1371/journal.pgen.1000040] [Citation(s) in RCA: 126] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2007] [Accepted: 02/26/2008] [Indexed: 12/20/2022] Open
Abstract
Progress in unravelling the cellular and molecular basis of mammalian circadian regulation over the past decade has provided us with new avenues through which we can explore central nervous system disease. Deteriorations in measurable circadian output parameters, such as sleep/wake deficits and dysregulation of circulating hormone levels, are common features of most central nervous system disorders. At the core of the mammalian circadian system is a complex of molecular oscillations within the hypothalamic suprachiasmatic nucleus. These oscillations are modifiable by afferent signals from the environment, and integrated signals are subsequently conveyed to remote central neural circuits where specific output rhythms are regulated. Mutations in circadian genes in mice can disturb both molecular oscillations and measurable output rhythms. Moreover, systematic analysis of these mutants indicates that they can express an array of abnormal behavioural phenotypes that are intermediate signatures of central nervous system disorders. Furthermore, the response of these mutants to psychoactive drugs suggests that clock genes can modify a number of the brain's critical neurotransmitter systems. This evidence has led to promising investigations into clock gene polymorphisms in psychiatric disease. Preliminary indications favour the systematic investigation of the contribution of circadian genes to central nervous system disease.
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Affiliation(s)
- Alun R. Barnard
- Neurobehavioural Genetics Group, Medical Research Council Mammalian Genetics Unit, Harwell, Oxfordshire, United Kingdom
| | - Patrick M. Nolan
- Neurobehavioural Genetics Group, Medical Research Council Mammalian Genetics Unit, Harwell, Oxfordshire, United Kingdom
- * E-mail:
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12
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Wisor JP, Striz M, DeVoss J, Murphy GM, Edgar DM, O'Hara BF. A novel quantitative trait locus on mouse chromosome 18, "era1," modifies the entrainment of circadian rhythms. Sleep 2008; 30:1255-63. [PMID: 17969459 DOI: 10.1093/sleep/30.10.1255] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
STUDY OBJECTIVE The mammalian circadian clock in the suprachiasmatic nuclei (SCN) of the hypothalamus conveys 24-h rhythmicity to sleep-wake cycles, locomotor activity, and other behavioral and physiological processes. The timing of rhythms relative to the light/dark (LD12:12) cycle is influenced in part by the endogenous circadian period and the time of day specific sensitivity of the clock to light. We now describe a novel circadian rhythm phenotype, and a locus influencing that phenotype, in a segregating population of mice. METHODS By crossbreeding 2 genetically distinct nocturnal strains of mice (Cast/Ei and C57BL/6J) and backcrossing the resulting progeny to Cast/Ei, we have produced a novel circadian phenotype, called early runner mice. RESULTS Early runner mice entrain to a light/dark cycle at an advanced phase, up to 9 hours before dark onset. This phenotype is not significantly correlated with circadian period in constant darkness and is not associated with disruption of molecular circadian rhythms in the SCN, as assessed by analysis of period gene expression. We have identified a genomic region that regulates this phenotype-a major quantitative trait locus on chromosome 18 (near D18Mit184) that we have named era1 for Early Runner Activity locus one. Phase delays caused by light exposure early in the subjective night were of smaller magnitude in backcross offspring that were homozygous Cast/Ei at D18Mit184 than in those that were heterozygous at this locus. CONCLUSION Genetic variability in the circadian response to light may, in part, explain the variance in phase angle of entrainment in this segregating mouse population.
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Affiliation(s)
- Jonathan P Wisor
- Molecular Neurobiology Laboratory, SRI International, Menlo Park, CA 94025, USA.
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13
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Hofstetter JR, Svihla-Jones DA, Mayeda AR. A QTL on mouse chromosome 12 for the genetic variance in free-running circadian period between inbred strains of mice. J Circadian Rhythms 2007; 5:7. [PMID: 17974007 PMCID: PMC2174920 DOI: 10.1186/1740-3391-5-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2007] [Accepted: 10/31/2007] [Indexed: 11/21/2022] Open
Abstract
Background Many genes control circadian period in mice. Prior studies suggested a quantitative trait locus (QTL) on proximal mouse chromosome 12 for interstrain differences in circadian period. Since the B6.D2NAhrd/J strain has DBA/2 alleles for a portion of proximal chromosome 12 introgressed onto its C57BL/6J background, we hypothesized that these mice would have a shorter circadian period than C57BL/6J mice. Methods We compared circadian phenotypes of B6.D2NAhrd/J and C57BL/6 mice: period of general locomotor activity in constant dark and rest/activity pattern in alternating light and dark. We genotyped the B6.D2NAhrd/J mice to characterize the size of the genomic insert. To aid in identifying candidate quantitative trait genes we queried databases about the resident SNPs, whole brain gene expression in C57BL/6J versus DBA/2J mice, and circadian patterns of gene expression. Results The B6.D2NAhrd/J inbred mice have a shorter circadian period of locomotor activity than the C57BL/6J strain. Furthermore, the genomic insert is associated with another phenotype: the mean phase of activity minimum in the dark part of a light-dark lighting cycle. It was one hour later than in the background strain. The B6.D2NAhrd/J mice have a DBA/2J genomic insert spanning 35.4 to 41.0 megabase pairs on Chromosome 12. The insert contains 15 genes and 12 predicted genes. In this region Ahr (arylhydrocarbon receptor) and Zfp277 (zinc finger protein 277) both contain non-synonymous SNPs. Zfp277 also showed differential expression in whole brain and was cis-regulated. Three genes and one predicted gene showed a circadian pattern of expression in liver, including Zfp277. Conclusion We not only fine-mapped the QTL for circadian period on chromosome 12 but found a new QTL there as well: an association with the timing of the nocturnal activity-minimum. Candidate quantitative trait genes in this QTL are zinc finger protein 277 and arylhydrocarbon receptor. Arylhydrocarbon receptor is structurally related to Bmal1, a canonical clock gene.
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Affiliation(s)
- John R Hofstetter
- Department of Psychiatry, Richard L, Roudebush Veterans Administration Medical Center (VAMC), Indianapolis, IN 46202, USA.
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14
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Hofstetter JR, Hitzemann RJ, Belknap JK, Walter NAR, McWeeney SK, Mayeda AR. Characterization of the quantitative trait locus for haloperidol-induced catalepsy on distal mouse chromosome 1. GENES BRAIN AND BEHAVIOR 2007; 7:214-23. [PMID: 17696997 DOI: 10.1111/j.1601-183x.2007.00340.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We report here the confirmation of the quantitative trait locus for haloperidol-induced catalepsy on distal chromosome (Chr) 1. We determined that this quantitative trait locus was captured in the B6.D2-Mtv7a/Ty congenic mouse strain, whose introgressed genomic interval extends from approximately 169.1 to 191.3 Mb. We then constructed a group of overlapping interval-specific congenic strains to further break up the interval and remapped the locus between 177.5 and 183.4 Mb. We next queried single nucleotide polymorphism (SNP) data sets and identified three genes with nonsynonymous coding SNPs in the quantitative trait locus. We also queried two brain gene expression data sets and found five known genes in this 5.9-Mb interval that are differentially expressed in both whole brain and striatum. Three of the candidate quantitative trait genes were differentially expressed using quantitative real-time polymerase chain reaction analyses. Overall, the current study illustrates how multiple approaches, including congenic fine mapping, SNP analysis and microarray gene expression screens, can be integrated both to reduce the quantitative trait locus interval significantly and to detect promising candidate quantitative trait genes.
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Affiliation(s)
- J R Hofstetter
- Department of Veterans Affairs, Richard L. Roudebush Medical Center, Indianapolis, IN 46202, USA.
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15
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Iwata M, Iwakawa M, Noda S, Ohta T, Minfu Y, Kimura T, Shibuya H, Imai T. Correlation between single nucleotide polymorphisms and jejunal crypt cell apoptosis after whole body irradiation. Int J Radiat Biol 2007; 83:181-6. [PMID: 17378526 DOI: 10.1080/09553000601146923] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
PURPOSE To identify loci concerned with radiosensitivity in a mouse model using single nucleotide polymorphism (SNP) markers. MATERIALS AND METHODS We subjected 276 second filial generation (F2) mice descended from two inbred mouse strains, radiation-induced apoptosis sensitive C57BL/6JNrs (B6) and radiation-induced apoptosis resistant C3H/HeNrs (C3H), to 2.5 Gy whole-body irradiation. We quantified jejunal crypt apoptosis, performed a genome-wide survey, and identified quantitative trait loci (QTL) associated with radiation sensitivity. We expressed apoptosis levels as an apoptotic score (AS), which was equal to the number of apoptotic bodies divided by the number of crypts. We genotyped the mice for 109 SNP markers. RESULTS AS values were 97.7+/-32.9 in B6 mice and 49.0+/-24.9 in C3H mice (p < 0.01). Genome-wide analysis revealed 8 markers (2 on chromosome 9, 4 on 15, 1 on 17, and 1 on 18) affecting radiation-induced jejunal apoptosis with log odds (LOD) scores ranging from 2.11+/-3.91. We found a significant locus on chromosome 15, which was previously reported by Weil and colleagues. CONCLUSION These findings support the view that the radiosensitivity of clinically normal tissue depends on variations in several genes.
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Affiliation(s)
- Masaru Iwata
- Radgenomics Project, Frontier Research Center, National Institute of Radiological Sciences, Japan
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16
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Rhodes JS, Ford MM, Yu CH, Brown LL, Finn DA, Garland T, Crabbe JC. Mouse inbred strain differences in ethanol drinking to intoxication. GENES BRAIN AND BEHAVIOR 2007; 6:1-18. [PMID: 17233637 DOI: 10.1111/j.1601-183x.2006.00210.x] [Citation(s) in RCA: 272] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Recently, we described a simple procedure, Drinking in the Dark (DID), in which C57BL/6J mice self-administer ethanol to a blood ethanol concentration (BEC) above 1 mg/ml. The test consists of replacing the water with 20% ethanol in the home cage for 4 h early during the dark phase of the light/dark cycle. Three experiments were conducted to explore this high ethanol drinking model further. In experiment 1, a microanalysis of C57BL/6J behavior showed that the pattern of ethanol drinking was different from routine water intake. In experiment 2, drinking impaired performance of C57BL/6J on the accelerating rotarod and balance beam. In experiment 3, 12 inbred strains were screened to estimate genetic influences on DID and correlations with other traits. Large, reliable differences in intake and BEC were detected among the strains, with C57BL/6J showing the highest values. Strain means were positively correlated with intake and BEC in the standard (24 h) and a limited (4 h) two-bottle ethanol vs. water test, but BECs reached higher levels for DID. Strain mean correlations with other traits in the Mouse Phenome Project database supported previously reported genetic relationships of high ethanol drinking with low chronic ethanol withdrawal severity and low ethanol-conditioned taste aversion. We extend these findings by showing that the correlation estimates remain relatively unchanged even after correcting for phylogenetic relatedness among the strains, thus relaxing the assumption that the strain means are statistically independent. We discuss applications of the model for finding genes that predispose pharmacologically significant drinking in mice.
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Affiliation(s)
- J S Rhodes
- Department of Psychology, University of Illinois at Urbana-Champaign, Champaign, IL, USA.
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17
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Abstract
Bipolar disorder (BPD) is an often devastating illness characterized by extreme mood dysregulation. Although family, twin and adoption studies consistently indicate a strong genetic component, specific genes that contribute to the illness remain unclear. This study gives an overview of linkage studies of BPD, concluding that the regions with the best evidence for linkage include areas on chromosomes 2p, 4p, 4q, 6q, 8q, 11p, 12q, 13q, 16p, 16q, 18p, 18q, 21q, 22q and Xq. Association studies are summarized, which support a possible role for numerous candidate genes in BPD including COMT, DAT, HTR4, DRD4, DRD2, HTR2A, 5-HTT, the G72/G30 complex, DISC1, P2RX7, MAOA and BDNF. Animal models related to bipolar illness are also reviewed, with special attention paid to those with clear genetic implications. We conclude with suggestions for strategies that may help clarify the genetic bases of this complex illness.
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Affiliation(s)
- E P Hayden
- Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, IN 46202-4887, USA.
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18
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Kernek KL, Trofatter JA, Mayeda AR, Lahiri DK, Hofstetter JR. A single copy of carbonic anhydrase 2 restores wild-type circadian period to carbonic anhydrase II-deficient mice. Behav Genet 2006; 36:301-8. [PMID: 16408247 DOI: 10.1007/s10519-005-9032-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2005] [Accepted: 07/14/2005] [Indexed: 01/12/2023]
Abstract
Carbonic anhydrase II (CA-II)-deficient mice have long circadian periods compared to their siblings with normal CA-II levels. The CA-II-deficient mice differ genetically from their siblings at proximal chromosome three, where the mutated carbonic anhydrase 2 gene sits on a small insert of DNA from the DBA/2J strain. The rest of the genome is that of the C57BL/6J strain. The goal of this study was to test the hypothesis that the null mutation in carbonic anhydrase 2 and the long circadian period phenotype were linked. In order to separate the effect of the null mutation in carbonic anhydrase 2 from the effect of DBA/2J alleles of other genes on the insert, two new lines of mice were studied. The first line, Kar, was developed from a CA-II-deficient mouse that had a fortuitous recombination restoring functional CA-II without affecting the rest of the DBA/2J insert. The second line was generated by breeding DBA/2J mice and C57BL/6J mice until they had the genomic composition of CA-II-deficient mice without the null mutation. Both lines of mice had circadian periods not different from C57BL/6J mice and shorter than CA-II-deficient mice. The phenotype of the new lines showed that the long circadian period characteristic of the CA-II-deficient mice arises when functional CA-II is absent, not when DBA/2J alleles are present on proximal chromosome three.
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Affiliation(s)
- Kari L Kernek
- Program in Medical Neurobiology, Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, 46202, USA
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Sans-Fuentes MA, López-Fuster MJ, Ventura J, Díez-Noguera A, Cambras T. Effect of Robertsonian Translocations on the Motor Activity Rhythm in the House Mouse. Behav Genet 2005; 35:603-13. [PMID: 16184488 DOI: 10.1007/s10519-005-5375-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2004] [Accepted: 04/15/2005] [Indexed: 11/29/2022]
Abstract
Here we studied the circadian rhythm of motor activity in two groups of wild house mice from the chromosomal polymorphic zone of Barcelona, which differed in diploid number (2n): standard (2n = 40), with all acrocentric chromosomes, and Robertsonian (2n = 29-32), with several Robertsonian translocations. Motor activity under three lighting conditions, light-dark cycle, constant darkness, and constant light, was recorded for each mouse. The motor activity rhythm was examined by Fourier analysis and the daily power spectra were obtained. On the basis of the mean power spectrum of each animal and under each lighting condition, stepwise discriminant analyses were performed to classify the two chromosomal groups. This method allowed the correct classification of a large number of animals, the rhythms of about 2-2.6 hour periods being the most significant, with higher values in Robertsonian than in standard mice. Our results indicate that the daily motor activity pattern differs between the two chromosomal groups and its analysis may have a valuable interest for behavioral investigations on Robertsonian polymorphic zones of this species.
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Affiliation(s)
- Maria Assumpció Sans-Fuentes
- Departament de Biologia Animal, Facultat de Biologia, Universitat de Barcelona, Avda. Diagonal 645, 08028, Barcelona, Spain.
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DeBruyne J, Hurd MW, Gutiérrez L, Kaneko M, Tan Y, Wells DE, Cahill GM. Isolation and phenogenetics of a novel circadian rhythm mutant in zebrafish. J Neurogenet 2005; 18:403-28. [PMID: 15763996 DOI: 10.1080/01677060490894540] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Widespread use of zebrafish (Danio rerio) in genetic analysis of embryonic development has led to rapid advances in the technology required to generate, map and clone mutated genes. To identify genes involved in the generation and regulation of vertebrate circadian rhythmicity, we screened for dominant mutations that affect the circadian periodicity of larval zebrafish locomotor behavior. In a screen of 6,500 genomes, we recovered 8 homozygous viable, semi-dominant mutants, and describe one of them here. The circadian period of the lager and lime (lag(dg2)) mutant is shortened by 0.7 h in heterozygotes,and 1.3 h in homozygotes. This mutation also shortens the period of the melatonin production rhythm measured from cultured pineal glands, indicating that the mutant gene product affects circadian rhythmicity at the tissue level, as well as at the behavioral level. This mutation also alters the sensitivity of pineal circadian period to temperature, but does not affect phase shifting responses to light. Linkage mapping with microsatellite markers indicates that the lag mutation is on chromosome 7. A zebrafish homolog of period1(per1) is the only known clock gene homolog that maps near the lag locus. However, all sequence variants found in per1 cDNA from lag(dg2) mutants are also present in wild type lines, and we were unable to detect any defect in per1 mRNA splicing, so this mutation may identify a novel clock gene.
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Affiliation(s)
- Jason DeBruyne
- Department of Biology and Biochemistry, University of Houston, 4800 Calhoun, Houston, TX 77204, USA
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21
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Edwards KD, Lynn JR, Gyula P, Nagy F, Millar AJ. Natural allelic variation in the temperature-compensation mechanisms of the Arabidopsis thaliana circadian clock. Genetics 2005; 170:387-400. [PMID: 15781708 PMCID: PMC1449708 DOI: 10.1534/genetics.104.035238] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2004] [Accepted: 02/09/2005] [Indexed: 11/18/2022] Open
Abstract
Temperature compensation is a defining feature of circadian oscillators, yet no components contributing to the phenomenon have been identified in plants. We tested 27 accessions of Arabidopsis thaliana for circadian leaf movement at a range of constant temperatures. The accessions showed varying patterns of temperature compensation, but no clear associations to the geographic origin of the accessions could be made. Quantitative trait loci (QTL) were mapped for period and amplitude of leaf movement in the Columbia by Landsberg erecta (CoL) and Cape Verde Islands by Landsberg erecta (CvL) recombinant inbred lines (RILs) at 12 degrees , 22 degrees , and 27 degrees . Six CvL and three CoL QTL were located for circadian period. All of the period QTL were temperature specific, suggesting that they may be involved in temperature compensation. The flowering-time gene GIGANTEA and F-box protein ZEITLUPE were identified as strong candidates for two of the QTL on the basis of mapping in near isogenic lines (NILs) and sequence comparison. The identity of these and other candidates suggests that temperature compensation is not wholly determined by the intrinsic properties of the central clock proteins in Arabidopsis, but rather by other genes that act in trans to alter the regulation of these core proteins.
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Affiliation(s)
- Kieron D Edwards
- Department of Biological Sciences, University of Warwick, Coventry, UK
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22
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Abstract
This article discusses a number of common methodologies used in the field of population genetics and evolution and reviews their application within circadian rhythm research. We examine the basic principles behind phylogenetic analysis and how these can be used to illuminate clock gene evolution. We then discuss genetic variation between and within species and show how neutrality tests can reveal the signatures of selection or drift on clock genes. These tests are particularly important for moving beyond "just so" stories when discussing the evolution of clock phenotypes, and we provide relevant circadian examples. We also focus on methods that can be used to study genetic variation, such as quantitative trait loci analysis. We discuss the various bootstrapping or resampling techniques that can be applied to generate confidence intervals in the various methodologies and then examine the use of interspecific transformation studies, which can, and have, provide some useful insights, not only into clock gene evolution in particular, but "behavioral" gene evolution in general. Finally, we assess gene/protein alignments and protein structure predictions and their implicit evolutionary bases.
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