Functional Development of the Zebrafish Pineal Gland: Light-Induced Expression of Period2 is Required for Onset of the Circadian Clock

2005 ◽  
Vol 17 (5) ◽  
pp. 314-320 ◽  
Author(s):  
L. Ziv ◽  
S. Levkovitz ◽  
R. Toyama ◽  
J. Falcon ◽  
Y. Gothilf
Keyword(s):  
Pineal Gland ◽  
Circadian Clock ◽  
Induced Expression ◽  
Functional Development

scholarly journals Functional Development of the Circadian Clock in the Zebrafish Pineal Gland

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Zohar Ben-Moshe ◽  
Nicholas S. Foulkes ◽  
Yoav Gothilf
Keyword(s):  
Pineal Gland ◽  
Circadian Clock ◽  
Rapid Development ◽  
Model Organism ◽  
Circadian System ◽  
Zebrafish Model ◽  
Peripheral Oscillators ◽  
Clock Gene Expression ◽  
Functional Development ◽  
Central Clock

The zebrafish constitutes a powerful model organism with unique advantages for investigating the vertebrate circadian timing system and its regulation by light. In particular, the remarkably early and rapid development of the zebrafish circadian system has facilitated exploring the factors that control the onset of circadian clock function during embryogenesis. Here, we review our understanding of the molecular basis underlying functional development of the central clock in the zebrafish pineal gland. Furthermore, we examine how the directly light-entrainable clocks in zebrafish cell lines have facilitated unravelling the general mechanisms underlying light-induced clock gene expression. Finally, we summarize how analysis of the light-induced transcriptome and miRNome of the zebrafish pineal gland has provided insight into the regulation of the circadian system by light, including the involvement of microRNAs in shaping the kinetics of light- and clock-regulated mRNA expression. The relative contributions of the pineal gland central clock and the distributed peripheral oscillators to the synchronization of circadian rhythms at the whole animal level are a crucial question that still remains to be elucidated in the zebrafish model.

PEPTIDE REGULATES HUMAN CIRCADIAN RHYTHMS GENES EXPRESSION DURING PINEAL GLAND ACCELERATED AGING

2020 ◽  
pp. 429-435
Author(s):  
О. М. Ивко ◽  
Н. С. Линькова ◽  
А. Р. Ильина ◽  
А. А. Шарова ◽  
Г. А. Рыжак
Keyword(s):  
Circadian Rhythms ◽  
Pineal Gland ◽  
Circadian Clock ◽  
Peripheral Blood ◽  
Accelerated Aging ◽  
Peripheral Blood Lymphocytes ◽  
Circadian Genes ◽  
Blood Lymphocytes ◽  
Aged People ◽  
Genes Expression

Ночная работа приводит к десинхронизации биоритмов, нарушению мелатонинобразующей функции и ускоренному старению эпифиза человека. Одним из перспективных геропротекторов, восстанавливающих синтез эпифизарного мелатонина, является пептид AEDG ( Ala-Glu-Asp-Gly ). Последний в 1,7 раза повышает экскрецию 6-сульфатоксимелатонина в моче людей среднего возраста, у которых этот показатель исходно снижен. Кроме того, у людей со сниженной мелатонинобразующей функцией эпифиза, пептид AEDG нормализует повышенную экспрессию циркадных генов Clock и Csnk 1 e в лейкоцитах и в 2 раза повышает сниженную экспрессию гена Cry 2 в лимфоцитах крови. В основе геропротекторного эффекта пептида AEDG лежит его способность восстанавливать мелатонинобразующую функцию эпифиза через регуляцию экспрессии часовых генов человека. Night work provides biorhythms desynchronization, disorder of melatonin-producing function and accelerated pineal gland aging. One of the promising geroprotectors restoring the pineal melatonin synthesis is the AEDG ( Ala-Glu-Asp-Gly ) peptide. AEDG peptide increases in 1,7 times the 6-sulfatoxymelatonin (6-SOMT) excretion in the urine of middle-aged people. Moreover, AEDG peptide normalized circadian Clock and Csnk1e genes hyper expression in leukocytes in 1,9-2,1 times and increases the Cry 2 gene hypo expression in peripheral blood lymphocytes in 2 times in people with reduced melatonin-producing epiphysis function. The geroprotective effect of the AEDG peptide is based on its ability to restore the epiphysis melatonin-producing function by means regulation of human circadian genes expression.

Prenatal exposure to lipopolysaccharide induces changes in the circadian clock in the SCN and AA-NAT activity in the pineal gland

2020 ◽  
Vol 1743 ◽  
pp. 146952
Author(s):  
Veronika Spišská ◽  
Dominika Pačesová ◽  
Hana Míková ◽  
Petra Pohanová ◽  
Petr Telenský ◽  
...  
Keyword(s):  
Pineal Gland ◽  
Circadian Clock ◽  
Prenatal Exposure

Enhanced effect of daytime restricted feeding on the circadian rhythm of streptozotocin-induced type 2 diabetic rats

2012 ◽  
Vol 302 (9) ◽  
pp. E1027-E1035 ◽  
Author(s):  
Tao Wu ◽  
Fen ZhuGe ◽  
Lu Sun ◽  
Yinhua Ni ◽  
Ou Fu ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Pineal Gland ◽  
Circadian Clock ◽  
Clock Genes ◽  
Activity Rhythm ◽  
Diabetic Rats ◽  
Restricted Feeding ◽  
Behavioral Rhythm ◽  
Type 2 Diabetic

There is increasing awareness of the link between impaired circadian clocks and multiple metabolic diseases. However, the impairment of the circadian clock by type 2 diabetes has not been fully elucidated. To understand whether and how the function of circadian clock is impaired under the diabetic condition, we examined not only the expression of circadian genes in the heart and pineal gland but also the behavioral rhythm of type 2 diabetic and control rats in both the nighttime restricted feeding (NRF) and daytime restricted feeding (DRF) conditions. In the NRF condition, the circadian expression of clock genes in the heart and pineal gland was conserved in the diabetic rats, being similar to that in the control rats. DRF shifted the circadian phases of peripheral clock genes more efficiently in the diabetic rats than those in the control rats. Moreover, the activity rhythm of rats in the diabetic group was completely shifted from the dark phase to the light phase after 5 days of DRF treatment, whereas the activity rhythm of rats in the control group was still under the control of the suprachiasmatic nucleus (SCN) after the same DRF treatment. Furthermore, the serum glucose rhythm of type 2 diabetic rats was also shifted and controlled by the external feeding schedule, ignoring the SCN rhythm. Therefore, DRF shows stronger effect on the reentrainment of circadian rhythm in the type 2 diabetic rats, suggesting that the circadian system in diabetes is unstable and more easily shifted by feeding stimuli.

scholarly journals Circadian Clock Genes and Photoperiodism: Comprehensive Analysis of Clock Gene Expression in the Mediobasal Hypothalamus, the Suprachiasmatic Nucleus, and the Pineal Gland of Japanese Quail under Various Light Schedules

Endocrinology ◽  
2003 ◽  
Vol 144 (9) ◽  
pp. 3742-3748 ◽  
Author(s):  
Shinobu Yasuo ◽  
Miwa Watanabe ◽  
Naritoshi Okabayashi ◽  
Shizufumi Ebihara ◽  
Takashi Yoshimura
Keyword(s):  
Pineal Gland ◽  
Circadian Clock ◽  
Suprachiasmatic Nucleus ◽  
Clock Genes ◽  
Expression Patterns ◽  
Hypothalamic Nucleus ◽  
Mediobasal Hypothalamus ◽  
Clock Gene Expression ◽  
Circadian Clock Genes ◽  
Important Center

Abstract In birds, the mediobasal hypothalamus (MBH) including the infundibular nucleus, inferior hypothalamic nucleus, and median eminence is considered to be an important center that controls the photoperiodic time measurement. Here we show expression patterns of circadian clock genes in the MBH, putative suprachiasmatic nucleus (SCN), and pineal gland, which constitute the circadian pacemaker under various light schedules. Although expression patterns of clock genes were different between long and short photoperiod in the SCN and pineal gland, the results were not consistent with those under night interruption schedule, which causes testicular growth. These results indicate that different expression patterns of the circadian clock genes in the SCN and pineal gland are not an absolute requirement for encoding and decoding of seasonal information. In contrast, expression patterns of clock genes in the MBH were stable under various light conditions, which enables animals to keep a steady-state photoinducible phase.

Zebrafish arylalkylamine-N-acetyltransferase genes – targets for regulation of the circadian clock

2006 ◽  
Vol 36 (2) ◽  
pp. 337-347 ◽  
Author(s):  
L Appelbaum ◽  
D Vallone ◽  
A Anzulovich ◽  
L Ziv ◽  
M Tom ◽  
...  
Keyword(s):  
Circadian Rhythm ◽  
Pineal Gland ◽  
Circadian Clock ◽  
Fluorescent Protein ◽  
Transgenic Fish ◽  
Constant Darkness ◽  
Rhythmic Expression ◽  
E Box

Daily rhythms of melatonin production are controlled by changes in the activity of arylalkylamine-N-acetyltransferase (AANAT). Zebrafish possess two aanats, aanat1 and aanat2; the former is expressed only in the retina and the latter is expressed in both the retina and the pineal gland. Here, their differential expression and regulation were studied using transcript quantification and transient and stable in vivo and in vitro transfection assays. In the pineal gland, the aanat2 promoter exhibited circadian clock-controlled activity, as indicated by circadian rhythms of Enhanced green fluorescent protein (EGFP) mRNA in AANAT2:EGFP transgenic fish. In vivo transient expression analyses of the aanat2 promoter indicated that E-box and photoreceptor conserved elements (PCE) are required for expression in the pineal gland. In the retina, the expression of both genes was characterized by a robust circadian rhythm of their transcript levels. In constant darkness, the rhythmic expression of retinal aanat2 persisted while the aanat1 rhythm disappeared; indicating that the former is controlled by a circadian clock and the latter is also light driven. In the light-entrainable clock-containing PAC-2 zebrafish cell line, both stably transfected aanat1 and aanat2 promoters exhibited a clock-controlled circadian rhythm, characteristic for an E-box-driven expression. Transient co-transfection experiments in NIH-3T3 cells revealed that the two, E-box- and PCE-containing, promoters are driven by the synergistic action of BMAL/CLOCK and orthehodenticle homeobox 5. This study has revealed a shared mechanism for the regulation of two related genes, yet describes their differential phases and photic responses which may be driven by other gene-specific regulatory mechanisms and tissue-specific transcription factor profiles.

Photoreception and circadian clock system of the chicken pineal gland

2001 ◽  
Vol 53 (1) ◽  
pp. 72-80 ◽  
Author(s):  
Toshiyuki Okano ◽  
Yoshitaka Fukada
Keyword(s):  
Pineal Gland ◽  
Circadian Clock ◽  
Clock System

Circadian Clock System in the Pineal Gland

2002 ◽  
Vol 25 (1) ◽  
pp. 019-030 ◽  
Author(s):  
Yoshitaka Fukada ◽  
Toshiyuki Okano
Keyword(s):  
Pineal Gland ◽  
Circadian Clock ◽  
Clock System

scholarly journals Arylalkylamine N-Acetyltransferase: “the Timezyme”

2006 ◽  
Vol 282 (7) ◽  
pp. 4233-4237 ◽  
Author(s):  
David C. Klein
Keyword(s):  
Pineal Gland ◽  
Circadian Clock ◽  
Adenosine Monophosphate ◽  
Unique Role ◽  
Regulatory Systems ◽  
Regulatory Complex ◽  
Environmental Lighting ◽  
Melatonin Production ◽  
Daily Changes

Arylalkylamine N-acetyltransferase controls daily changes in melatonin production by the pineal gland and thereby plays a unique role in biological timing in vertebrates. Arylalkylamine N-acetyltransferase is also expressed in the retina, where it may play other roles in addition to signaling, including neurotransmission and detoxification. Large changes in activity reflect cyclic 3′,5′-adenosine monophosphate-dependent phosphorylation of arylalkylamine N-acetyltransferase, leading to formation of a regulatory complex with 14-3-3 proteins. This activates the enzyme and prevents proteosomal proteolysis. The conserved features of regulatory systems that control arylalkylamine N-acetyltransferase are a circadian clock and environmental lighting.

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