Dormancy, Diapause, and the Role of the Circadian System in Insect Photoperiodism

2020 ◽  
Vol 65 (1) ◽  
pp. 373-389 ◽  
Author(s):  
David S. Saunders
Keyword(s):  
Clock Genes ◽  
Animal Experiments ◽  
Transcript Abundance ◽  
Circadian System ◽  
Gene Transcript ◽  
Light Cycle ◽  
Peripheral Oscillators ◽  
Circadian Clock Genes ◽  
Similar Phase

Whole-animal experiments devised to investigate possible association between photoperiodic time measurement and the circadian system (Bünning's hypothesis) are compared with more recent molecular investigations of circadian clock genes. In Sarcophaga argyrostoma and some other species, experimental cycles of light and darkness revealed a photoperiodic oscillator, set to constant phase at dusk and measuring night length repeatedly during extended periods of darkness. In some species, however, extreme dampening revealed an unrepetitive (i.e., hourglass-like) response. Rhythms of clock gene transcript abundance may also show similar phase relationships to the light cycle, and gene silencing of important clock genes indicates that they play a crucial role in photoperiodism either alone or in concert. However, the multiplicity of peripheral oscillators in the insect circadian system indicates that more complex mechanisms might also be important.

THE ROLE OF CIRCADIAN REGULATION OF GHRELIN LEVELS IN PARKINSON’S DISEASE (LITERATURE REVIEW)

2021 ◽  
Vol 74 (7) ◽  
pp. 1750-1753
Author(s):  
Kateryna A. Tarianyk ◽  
Nataliya V. Lytvynenko ◽  
Anastasiia D. Shkodina ◽  
Igor P. Kaidashev
Keyword(s):  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Clock Genes ◽  
Biological Rhythms ◽  
Circadian Regulation ◽  
Diurnal Changes ◽  
Dopaminergic Therapy ◽  
Peripheral Oscillators ◽  
Genes Expression

The paper is aimed at the analysis of the role of the circadian regulation of ghrelin levels in patients with Parkinson’s disease. Based on the literature data, patients with Parkinson’s disease have clinical fluctuations in the symptoms of the disease, manifested by the diurnal changes in motor activity, autonomic functions, sleep-wake cycle, visual function, and the efficacy of dopaminergic therapy. Biological rhythms are controlled by central and peripheral oscillators which links with dopaminergic neurotransmission – core of the pathogenesis of Parkinson`s disease. Circadian system is altered in Parkinson`s disease due to that ghrelin fluctuations may be changed. Ghrelin is potential food-entrainable oscillator because it is linked with clock genes expression. In Parkinson`s disease this hormone may induce eating behavior changing and as a result metabolic disorder. The “hunger hormone” ghrelin can be a biomarker of the Parkinson’s disease, and the study of its role in the pathogenesis, as well as its dependence on the period of the day, intake of levodopa medications to improve the effectiveness of treatment is promising.

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

scholarly journals Different Effects of Phase Advance and Delay in Rotating Light-Dark Regimens on Clock and Natriuretic Peptide Gene Expression in the Rat Heart

2014 ◽  
pp. S573-S584 ◽  
Author(s):  
I. HERICHOVÁ ◽  
J. AMBRUŠOVÁ ◽  
Ľ. MOLČAN ◽  
A. VESELÁ ◽  
P. SVITOK ◽  
...  
Keyword(s):  
Gene Expression ◽  
Clock Genes ◽  
Active Phase ◽  
Circadian System ◽  
Daily Rhythm ◽  
Male Rats ◽  
Phase Advance ◽  
Peripheral Oscillators ◽  
Peptide Gene ◽  
Central Oscillator

Under physiological conditions the mammalian circadian system is synchronized to a cyclic environment. The central oscillator in the suprachiasmatic nuclei (SCN) responds predominantly to an external light (L) dark (D) cycle. Peripheral oscillators are more efficiently synchronized by metabolic cues. When the circadian system is exposed to opposing synchronizing cues, peripheral oscillators uncouple from the SCN. To consider influence of phase advances and delays in light regimens mimicking shift work, we analyzed the expression of clock genes (per2, bmal1) and natriuretic peptides (anp, bnp) in the heart of male rats. Experimental groups were exposed to a rotating LD regimen with either 8 h phase advance or delay for 11 weeks. Samples were taken for a 24 h cycle in 4 h intervals. Peripheral oscillators responded to rotating phase advance by decreasing rhythm robustness, while phase delay mostly influenced the phase angle between the acrophase of rhythmic gene expression and the external LD cycle. The expression of anp was arrhythmic in the heart of control rats and was not influenced by rotating LD regimens. The expression of bnp showed a daily rhythm with a nadir during the active phase. The daily rhythm in bnp expression diminished under rotating LD regimen conditions.

Expression of circadian clock genes in retinal dopaminergic cells

2007 ◽  
Vol 24 (4) ◽  
pp. 573-580 ◽  
Author(s):  
RONALD DORENBOS ◽  
MASSIMO CONTINI ◽  
HAJIME HIRASAWA ◽  
STEFANO GUSTINCICH ◽  
ELIO RAVIOLA
Keyword(s):  
Circadian Clock ◽  
Light Adaptation ◽  
Clock Genes ◽  
Negative Control ◽  
Circadian Oscillators ◽  
Interesting Candidate ◽  
Circadian Clock Genes ◽  
Core Components ◽  
A Site

The mammalian neural retina contains single or multiple intrinsic circadian oscillators that can be directly entrained by light cycles. Dopaminergic amacrine (DA) cells represent an especially interesting candidate as a site of the retinal oscillator because of the crucial role of dopamine in light adaptation, and the widespread distribution of dopamine receptors in the retina. We hereby show by single-cell, end-point RT-PCR that retinal DA cells contain the transcripts for six core components of the circadian clock: Bmal1, Clock, Cry1, Cry2, Per1, and Per2. Rod photoreceptors represented a negative control, because they did not appear to contain clock transcripts. We finally confirmed that DA cells contain the protein encoded by the Bmal1 gene by comparing immunostaining of the nuclei of DA cells in the retinas of wildtype and Bmal1−/− mice. It is therefore likely that DA cells contain a circadian clock that anticipates predictable variations in retinal illumination.

scholarly journals Circadian System and Melatonin Hormone: Risk Factors for Complications during Pregnancy

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
F. J. Valenzuela ◽  
J. Vera ◽  
C. Venegas ◽  
F. Pino ◽  
C. Lagunas
Keyword(s):  
Intrauterine Growth Restriction ◽  
Clock Genes ◽  
Circadian System ◽  
Vascular Endothelial ◽  
Local Production ◽  
Intrauterine Growth ◽  
Increased Risk ◽  
Available Information ◽  
Endothelial Growth Factor

Pregnancy is a complex and well-regulated temporal event in which several steps are finely orchestrated including implantation, decidualization, placentation, and partum and any temporary alteration has serious effects on fetal and maternal health. Interestingly, alterations of circadian rhythms (i.e., shiftwork) have been correlated with increased risk of preterm delivery, intrauterine growth restriction, and preeclampsia. In the last few years evidence is accumulating that the placenta may have a functional circadian system and express the clock genesBmal1,Per1-2, andClock. On the other hand, there is evidence that the human placenta synthesizes melatonin, hormone involved in the regulation of the circadian system in other tissues. Moreover, is unknown the role of this local production of melatonin and whether this production have a circadian pattern. Available information indicates that melatonin induces in placenta the expression of antioxidant enzymes catalase and superoxide dismutase, prevents the injury produced by oxidative stress, and inhibits the expression of vascular endothelial growth factor (VEGF) a gene that in other tissues is controlled by clock genes. In this review we aim to analyze available information regarding clock genes and clock genes controlled genes such as VEGF and the possible role of melatonin synthesis in the placenta.

scholarly journals The role of circadian clock genes in the photoperiodic timer of the linden bugPyrrhocoris apterusduring the nymphal stage

2017 ◽  
Vol 42 (3) ◽  
pp. 266-273 ◽  
Author(s):  
Joanna Kotwica-Rolinska ◽  
Lenka Pivarciova ◽  
Hanka Vaneckova ◽  
David Dolezel
Keyword(s):  
Circadian Clock ◽  
Clock Genes ◽  
Nymphal Stage ◽  
Circadian Clock Genes

Reduced Endometrial Ascension and Enhanced Reinfection Associated with IgG Antibodies to Specific Chlamydia trachomatis Proteins in Women at Risk for Chlamydia

2021 ◽  
Author(s):  
Chuwen Liu ◽  
Katrin Hufnagel ◽  
Catherine M O’Connell ◽  
Nilu Goonetilleke ◽  
Neha Mokashi ◽  
...  
Keyword(s):  
Chlamydia Trachomatis ◽  
Transcript Abundance ◽  
Stepwise Logistic Regression ◽  
Gene Transcript ◽  
Igg Antibody ◽  
Wilcoxon Rank Sum Test ◽  
Gene Transcripts ◽  
The Impact ◽  
Incident Infection

Abstract Background Previous research revealed antibodies targeting Chlamydia trachomatis (CT) elementary bodies was not associated with reduced endometrial or incident infection in CT-exposed women. However, data on the role of CT protein-specific antibodies in protection are limited. Methods A whole-proteome CT array screening serum pools from CT-exposed women identified 121 immunoprevalent proteins. Individual sera were probed using a focused array. IgG antibody frequencies and endometrial or incident infection relationships were examined using Wilcoxon Rank sum test. The impact of breadth and magnitude of protein-specific IgGs on ascension and incident infection were examined using multivariable stepwise logistic regression. Complementary RNA-sequencing quantified CT gene transcripts in cervical swabs from infected women. Results IgG to Pgp3 and CT005 were associated with reduced endometrial infection; anti-CT443, -CT486 and -CT123 were associated with increased incident infection. Increased breadth of protein recognition did not however predict protection from endometrial or incident infection. mRNAs for immunoprevalent CT proteins were highly abundant in the cervix. Conclusions Protein-specific CT antibodies are not sufficient to protect against ascending or incident infection but broad recognition of CT proteins by IgG correlates with cervical CT gene transcript abundance, suggesting CT protein abundance correlates with immunogenicity and signifies their potential as vaccine candidates.

Role of PPARα in control of torpor through FGF21-NPY pathway: From circadian clock genes to seasonal change and cardiovascular disease

2010 ◽  
Vol 8 (1) ◽  
pp. 2-8
Author(s):  
Norio K ISHIDA ◽  
Daisuke UCHIDA ◽  
Ryosuke DOI ◽  
Katsutaka OISHI ◽  
Sachiko CHIKAHISA ◽  
...  
Keyword(s):  
Cardiovascular Disease ◽  
Circadian Clock ◽  
Seasonal Change ◽  
Clock Genes ◽  
Circadian Clock Genes
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