scholarly journals The day/night difference in the circadian clock’s response to acute lipopolysaccharide and the rhythmic Stat3 expression in the rat suprachiasmatic nucleus

2018 ◽  
Author(s):  
Simona Moravcová ◽  
Dominika Pačesová ◽  
Barbora Melkes ◽  
Hana Kyclerová ◽  
Veronika Spišská ◽  
...  
Keyword(s):  
Locomotor Activity ◽  
Circadian Clock ◽  
Suprachiasmatic Nucleus ◽  
Clock Genes ◽  
Activity Patterns ◽  
Night Time ◽  
Male Wistar Rats ◽  
And Function ◽  
External Signals

AbstractThe circadian clock in the suprachiasmatic nucleus (SCN) regulates daily rhythms in physiology and behaviour and is an important part of the mammalian homeostatic system. Previously, we have shown that systemic inflammatory stimulation with lipopolysaccharide (LPS) induced the daytime-dependent phosphorylation of STAT3 in the SCN. Here, we demonstrate the LPS-induced Stat3 mRNA expression in the SCN and show also the circadian rhythm in Stat3 expression in the SCN, with high levels during the day. Moreover, we examined the effects of LPS (1mg/kg), applied either during the day or the night, on the rhythm in locomotor activity of male Wistar rats. We observed that recovery of normal locomotor activity patterns took longer when the animals were injected during the night. The clock genes Per1, Per2 and Nr1d1, and phosphorylation of kinases ERK1/2 and GSK3β are sensitive to external cues and function as the molecular entry for external signals into the circadian clockwork. We also studied the immediate changes in these clock genes expressions and the phosphorylation of ERK1/2 and GSK3β in the suprachiasmatic nucleus in response to daytime or night-time inflammatory stimulation. We revealed mild and transient changes with respect to the controls. Our data stress the role of STAT3 in the circadian clock response to the LPS and provide further evidence of the interaction between the circadian clock and immune system.

Identification of the suprachiasmatic nucleus in birds

2001 ◽  
Vol 280 (4) ◽  
pp. R1185-R1189 ◽  
Author(s):  
Takashi Yoshimura ◽  
Shinobu Yasuo ◽  
Yoshikazu Suzuki ◽  
Eri Makino ◽  
Yuki Yokota ◽  
...  
Keyword(s):  
Locomotor Activity ◽  
Circadian Rhythms ◽  
Circadian Clock ◽  
Suprachiasmatic Nucleus ◽  
Japanese Quail ◽  
Clock Genes ◽  
Biological Clock ◽  
Circadian Oscillators ◽  
Circadian Clock Genes ◽  
Dim Light

Circadian rhythms are generated by an internal biological clock. The suprachiasmatic nucleus (SCN) in the hypothalamus is known to be the dominant biological clock regulating circadian rhythms in mammals. In birds, two nuclei, the so-called medial SCN (mSCN) and the visual SCN (vSCN), have both been proposed to be the avian SCN. However, it remains an unsettled question which nuclei are homologous to the mammalian SCN. We have identified circadian clock genes in Japanese quail and demonstrated that these genes are expressed in known circadian oscillators, the pineal and the retina. Here, we report that these clock genes are expressed in the mSCN but not in the vSCN in Japanese quail, Java sparrow, chicken, and pigeon. In addition, mSCN lesions eliminated or disorganized circadian rhythms of locomotor activity under constant dim light, but did not eliminate entrainment under light-dark (LD) cycles in pigeon. However, the lesioned birds became completely arrhythmic even under LD after the pineal and the eye were removed. These results indicate that the mSCN is a circadian oscillator in birds.

scholarly journals Transcriptomal dissection of soybean circadian rhythmicity in two geographically, phenotypically and genetically distinct cultivars

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Yanlei Yue ◽  
Ze Jiang ◽  
Enoch Sapey ◽  
Tingting Wu ◽  
Shi Sun ◽  
...  
Keyword(s):  
Gene Expression ◽  
Circadian Clock ◽  
Chromosome Structure ◽  
Clock Genes ◽  
Expression Profiles ◽  
Circadian Rhythmicity ◽  
Rna Seq ◽  
Night Time ◽  
Time Points ◽  
Circadian Clock Genes

Abstract Background In soybean, some circadian clock genes have been identified as loci for maturity traits. However, the effects of these genes on soybean circadian rhythmicity and their impacts on maturity are unclear. Results We used two geographically, phenotypically and genetically distinct cultivars, conventional juvenile Zhonghuang 24 (with functional J/GmELF3a, a homolog of the circadian clock indispensable component EARLY FLOWERING 3) and long juvenile Huaxia 3 (with dysfunctional j/Gmelf3a) to dissect the soybean circadian clock with time-series transcriptomal RNA-Seq analysis of unifoliate leaves on a day scale. The results showed that several known circadian clock components, including RVE1, GI, LUX and TOC1, phase differently in soybean than in Arabidopsis, demonstrating that the soybean circadian clock is obviously different from the canonical model in Arabidopsis. In contrast to the observation that ELF3 dysfunction results in clock arrhythmia in Arabidopsis, the circadian clock is conserved in soybean regardless of the functional status of J/GmELF3a. Soybean exhibits a circadian rhythmicity in both gene expression and alternative splicing. Genes can be grouped into six clusters, C1-C6, with different expression profiles. Many more genes are grouped into the night clusters (C4-C6) than in the day cluster (C2), showing that night is essential for gene expression and regulation. Moreover, soybean chromosomes are activated with a circadian rhythmicity, indicating that high-order chromosome structure might impact circadian rhythmicity. Interestingly, night time points were clustered in one group, while day time points were separated into two groups, morning and afternoon, demonstrating that morning and afternoon are representative of different environments for soybean growth and development. However, no genes were consistently differentially expressed over different time-points, indicating that it is necessary to perform a circadian rhythmicity analysis to more thoroughly dissect the function of a gene. Moreover, the analysis of the circadian rhythmicity of the GmFT family showed that GmELF3a might phase- and amplitude-modulate the GmFT family to regulate the juvenility and maturity traits of soybean. Conclusions These results and the resultant RNA-seq data should be helpful in understanding the soybean circadian clock and elucidating the connection between the circadian clock and soybean maturity.

scholarly journals The plant circadian clock influences rhizosphere community structure and function

2017 ◽  
Author(s):  
Charley J. Hubbard ◽  
Marcus T. Brock ◽  
Linda T.A. van Diepen ◽  
Loïs Maignien ◽  
Brent E. Ewers ◽  
...  
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Circadian Clock ◽  
Structure And Function ◽  
Plant Performance ◽  
Wild Type ◽  
Night Time ◽  
History Of ◽  
And Function ◽  
Rhizosphere Community

AbstractPlants alter chemical and physical properties of soil, and thereby influence rhizosphere microbial community structure. The structure of microbial communities may in turn affect plant performance. Yet, outside of simple systems with pairwise interacting partners, the plant genetic pathways that influence microbial community structure remain largely unknown, as are the performance feedbacks of microbial communities selected by the host plant genotype. We investigated the role of the plant circadian clock in shaping rhizosphere community structure and function. We performed 16S rRNA gene sequencing to characterize rhizosphere bacterial communities of Arabidopsis thaliana between day and night time points, and tested for differences in community structure between wild-type (Ws) vs. clock mutant (toc1-21, ztl-30) genotypes. We then characterized microbial community function, by growing wild-type plants in soils with an overstory history of Ws, toc1-21 or ztl-30 and measuring plant performance. We observed that rhizosphere community structure varied between day and night time points, and clock misfunction significantly altered rhizosphere communities. Finally, wild-type plants germinated earlier and were larger when inoculated with soils having an overstory history of wild-type in comparison to clock mutant genotypes. Our findings suggest the circadian clock of the plant host influences rhizosphere community structure and function.

scholarly journals Role of Circadian Clock Genes in Sudden Cardiac Death: A Pilot Study

2017 ◽  
Vol 26 (4) ◽  
pp. 347-354 ◽  
Author(s):  
Naoto Tani ◽  
Tomoya Ikeda ◽  
Shigeki Oritani ◽  
Tomomi Michiue ◽  
Takaki Ishikawa
Keyword(s):  
Pilot Study ◽  
Sudden Cardiac Death ◽  
Circadian Clock ◽  
Cardiac Death ◽  
Clock Genes ◽  
Circadian Clock Genes

Nicotine-induced anxiogenic-like behaviours of rats in the elevated plus-maze: possible role of NMDA receptors of the central amygdala

2011 ◽  
Vol 26 (4) ◽  
pp. 555-563 ◽  
Author(s):  
Mohammad Reza Zarrindast ◽  
Arash Aghamohammadi-Sereshki ◽  
Ameneh Rezayof ◽  
Parvin Rostami
Keyword(s):  
Locomotor Activity ◽  
Nmda Receptor ◽  
Nmda Receptors ◽  
Elevated Plus Maze ◽  
Nmda Receptor Antagonist ◽  
Central Amygdala ◽  
Receptor System ◽  
Plus Maze ◽  
Male Wistar Rats

The objective of the present study was to investigate the possible role of the N-methyl-D-aspartate (NMDA) receptor system of the central amygdala (CeA) in the anxiogenic-like effect of nicotine. Male Wistar rats with cannulas aimed to the CeA were submitted to the elevated plus-maze (EPM). Intraperitoneal (i.p.) injections of nicotine (0.6 and 0.8 mg/kg) decreased percentage open arm time spent (%OAT) and percentage open arm entries (%OAE), but not locomotor activity, indicating an anxiogenic-like response. Bilateral intra-CeA microinjection of NMDA (0.005–0.1 μ g/rat) decreased %OAT, but not %OAE and locomotor activity. Moreover, intra-CeA microinjection of NMDA (0.05 μ g) with an ineffective dose of nicotine (0.4 mg/kg, i.p.) reduced %OAT and %OAE without effect on locomotor activity. On the other hand, intra-CeA microinjection of the NMDA receptor antagonist D-AP5 (0.05–0.5 μ g/rat) increased both %OAT and %OAE, showing an anxiolytic-like effect of the drug. Co-administration of the same doses of D-AP5 with nicotine (0.6 mg/kg, i.p.) increased %OAT and %OAE, but not locomotor activity. Intra-CeA microinjection of D-AP5 reversed the response induced by NMDA (0.1 μ g/rat) in the EPM. The results may support the possible involvement of glutamate transmission, through NMDA receptors of central amygdala in the anxiogenic-like effect of nicotine in the EPM task.

Environmental Influence on Locomotor Activity in Nephrops Norvegicus (Crustacea: Decapoda)

1980 ◽  
Vol 60 (1) ◽  
pp. 103-113 ◽  
Author(s):  
T. H. Moller ◽  
E. Naylor
Keyword(s):  
Locomotor Activity ◽  
Light Intensity ◽  
Environmental Influence ◽  
Activity Patterns ◽  
Nephrops Norvegicus ◽  
Experimental Conditions ◽  
Emergence Patterns ◽  
Role Of Light ◽  
Trawl Catches

Diel variations in the emergence of the burrowing prawn Nephrops norvegicus (L.) have been investigated by direct field observations (Chapman & Rice, 1971; Chapman, Johnstone & Rice, 1975; Chapman & Howard, 1979; Atkinson & Naylor, 1976), and indirectly by sequential trawling during 24 h periods (Höglund & Dybern, 1965; Simpson, 1965; Hillis, 1971; Farmer, 1974; Atkinson & Naylor, 1976; Oakley, 1979). Peak emergence appears to be related to temporal and depth-dependent variations in daylight penetration, since Nephrops are apparently nocturnal in shallow waters, crepuscular as the depth increases, and diurnal at the greatest depths of their occurrence. This lends support to the suggestion that emergence occurs at an optimum light intensity (Hillis, 1971; Chapman, Priestley & Robertson, 1972; Chapman, et al., 1975; Chapman & Howard, 1979). However, additional factors influencing emergence of Nephrops from their burrows have also to be taken in account, since laboratory studies of locomotor activity in Nephrops have consistently revealed nocturnal activity patterns in light-dark (LD) regimes, with light inhibiting locomotor activity even at extremely low irradiance levels (Arechiga & Atkinson, 1975; Atkinson & Naylor, 1973, 1976; Naylor & Atkinson, 1976). Moreover, Hammond & Naylor (1977 a) have presented qualitative evidence that the nocturnal locomotor activity peak appears to be synchronized by falling light intensity at dusk. The differences between these experimental results and emergence patterns deduced from trawl catches and underwater observations of Nephrops have not been fully resolved by studies of the role of light intensity and of gradual light transitions (Arechiga & Atkinson, 1975; Hammond & Naylor, 1977 a, b). Thus the behavioural responses of Nephrops both in the field and in the laboratory need to be assessed in relation to more accurately quantified light changes. Also, despite earlier evaluation of the problem (Atkinson & Naylor, 1976; Hammond & Naylor, 1977a) it is necessary to reconsider the possibility that the patterns of locomotor activity recorded in the laboratory are influenced by experimental conditions, as has been demonstrated for minnows (Jones, 1956), and flatfish (Verheijen & de Groot, 1967).

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