Time-of-day-dependent light-induction of gene expression in the chicken pineal gland
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ABSTRACT:
ORGANISM(S): Gallus gallus
PROVIDER: GSE21915 | GEO | 2011/03/08
SECONDARY ACCESSION(S): PRJNA126793
REPOSITORIES: GEO
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Project description:Light has a strong effect on whole organism physiology, such as the circadian rhythms that are phase delayed and advanced by light given at early and late subjective night, respectively. Despite the importance of the phase-dependent light responses, little is known about the underlying molecular mechanism. We performed a comprehensive analysis of genes induced by light in a phase-dependent manner in the chicken pineal gland, an organ that represents a unique vertebrate clock system harboring intrinsic light sensitivity. Newborn chicks were entrained to 12-h light/12-h dark cycle for 7 days then transferred to constant darkness for a day to be exposed to light for 1 h from CT (circadian time) 6 (representing subjective day), CT14 (early subjective night) or CT22 (late subjective night). Control animals were kept in the dark without light pulse. The pineal glands were isolated at the end of the 1-h light pulse for gene expression analysis by Affymetrix GeneChip. Each condition contains 2 biological samples.
2011-03-08 | E-GEOD-21915 | biostudies-arrayexpress
Project description:Light is the primary environmental cue in resetting the phase of circadian pacemaker in vertebrates. In birds, the effect of light is partly mediated by modulating the levels of circadian genes in the pineal gland. To further elucidate the mechanism by which light resets the circadian clock, we studied gene expression in the chicken pineal gland under acutely extended light period. Three paradigms of treatments were used in this study. For each paradigm, chicks were assigned at random to control treatment (control groups) or light treatment (light groups). All birds in control groups were given 12 h light and 12 h dark period (LD 12:12). Light-on time is referred to as Zeitgeber Time 0 (ZT0). In paradigm 1, birds in the light group (n =25 for each of the groups in each paradigm) were acclimated to LD 12:12 for one week in the same light scheme as were the control birds, then exposed to light for 2 h during the subjective late night (ZT22 to ZT24) on the last day. All birds (including the controls) were sacrificed at ZT0. Pineal glands were dissected and 5-6 pineal glands were pooled for the preparation of one RNA sample. In paradigm 2, birds in the light group were acclimated as in paradigm 1 for one week, then exposed to light for 2 h during the early subjective night (ZT12 to ZT14) on the last day. All birds (including controls) were sacrificed at ZT14. The pineal glands were also pooled as before. In paradigm 3, birds in the light group (n = 25) were kept in LD 15:9 cycle all the time, and all birds (including controls) were sacrificed at ZT14. Similarly, 5-6 pineal glands in the same treatment were pooled.
2015-06-30 | E-GEOD-34017 | biostudies-arrayexpress
Project description:Chick pinealocytes exhibit all the characteristics of a complete circadian system, comprising photoreceptive inputs, molecular clockworks and an easily measured rhythmic output, melatonin biosynthesis. We used microarray analysis to investigate the expression of approximately 8000 genes within cultured pinealocytes subjected to both LD and DD cycles. We report that a reduced subset of genes were rhythmically expressed in vitro compared to those previously published in vivo, and that gene expression rhythms were lower in amplitude, although the functional distribution of the rhythmic transcriptome was largely similar. We also investigated the effects of 6-hour pulses of light or of norepinephrine on gene expression in free-running cultures during both subjective day and night. As expected, both light and norepinephrine inhibited melatonin production; however, the two treatments differentially up- or down-regulated specific sets of genes in a fashion that was dependent upon time of day. Our combined approach of utilizing a time of day study and a light/NE pulse microarray experiment allowed us to identify novel genes linking clock input to clock function within the pineal. We identified approximately 30 rhythmic, light-responsive, NE-insensitive genes with no previously known clock function, which may play a role in circadian regulation of the pineal. These are candidates for future functional genomics experiments to elucidate their potential role in pineal physiology. Keywords: circadian; avian; pineal; light; norepinephrine
2008-07-04 | GSE5292 | GEO
Project description:Chick pinealocytes exhibit all the characteristics of a complete circadian system, comprising photoreceptive inputs, molecular clockworks and an easily measured rhythmic output, melatonin biosynthesis. We used microarray analysis to investigate the expression of approximately 8000 genes within cultured pinealocytes subjected to both LD and DD cycles. We report that a reduced subset of genes were rhythmically expressed in vitro compared to those previously published in vivo, and that gene expression rhythms were lower in amplitude, although the functional distribution of the rhythmic transcriptome was largely similar. We also investigated the effects of 6-hour pulses of light or of norepinephrine on gene expression in free-running cultures during both subjective day and night. As expected, both light and norepinephrine inhibited melatonin production; however, the two treatments differentially up- or down-regulated specific sets of genes in a fashion that was dependent upon time of day. Our combined approach of utilizing a time of day study and a light/NE pulse microarray experiment allowed us to identify novel genes linking clock input to clock function within the pineal. We identified approximately 30 rhythmic, light-responsive, NE-insensitive genes with no previously known clock function, which may play a role in circadian regulation of the pineal. These are candidates for future functional genomics experiments to elucidate their potential role in pineal physiology. Keywords: circadian; avian; pineal; light; norepinephrine Microarray analysis was performed on pineal samples subjected to one of four experimental groups: cultures placed within a 12-hour light:12-hour dark cycle (LD); cultures placed in continuous darkness (DD); cultures subjected to a 6-hour light pulse beginning at either CT0 or CT12 (i.e., zero or 12 hours after the beginning of subjective day) or that received no light pulse; and cultures subjected to 6 hours of NE treatment beginning at either CT0 or CT12 or that received similarly administered vehicle. For LD and DD groups, time-course sampling was performed such that 6 samples were collected over the course of a day at 4-hour intervals. For the light pulse and NE administration groups, 2 samples were collected over the course of a day, either at CT6 or CT18 (i.e., 6 or 18 hours after the beginning of subjective day). Four biological replicates and two technical replicates (for each biological repeat) were performed for each sample. For the LD and DD groups, time-points ZT18 and CT18 served as the control reference for the time-course analysis. For the light pulse experiment, cultures that did not receive light served as the control. For the NE administration experiment, cultures that received vehicle served as the control. Dye swaps for performed for experimental samples from the light pulse and NE administration experiments.
2008-07-04 | E-GEOD-5292 | biostudies-arrayexpress
Project description:Light is the primary environmental cue in resetting the phase of circadian pacemaker in vertebrates. In birds, the effect of light is partly mediated by modulating the levels of circadian genes in the pineal gland. To further elucidate the mechanism by which light resets the circadian clock, we studied gene expression in the chicken pineal gland under acutely extended light period.
2015-06-30 | GSE34017 | GEO
Project description:The mammalian master circadian pacemaker within the suprachiasmatic nucleus (SCN) maintains tight entrainment to the 24 hr light/dark cycle via a sophisticated clock-gated rhythm in the responsiveness of the oscillator to light. Intriguingly, entrainment is not merely a passive response, instead the internal oscillator responds and adjust its own timing to entrainment signals discriminating the time of day. For example, exposure to brief light pulses in the first and final hours of the subjective generate circadian phase delays and advances respectively; whereas similar photic pulses during the subjective day does not modify the phase. A central event in this light entrainment process appears to be the rapid induction of gene expression via the ERK/MAPK pathway. We used microarray-based expression profiling of the suprachiasmatic nucleus to examine the role of MAPK signaling in the light-evoked transcriptional response. We focused on three circadian timepoints that define the unique, clock-time delimited response properties of the SCN to light: the subjective day, early subjective night, and late subjective night.
2021-03-24 | GSE165799 | GEO
Project description:Microarray data allowed detection of genes that are induced by light in the zebrafish pineal gland
2013-12-14 | GSE53288 | GEO
Project description:Biological processes are optimized by circadian and circannual biological timing systems. In vertebrates, the pineal gland plays an essential role in these systems by converting time into a hormonal signal, melatonin; in all vertebrates, circulating melatonin is elevated at night, independent of lifestyle. At night, sympathetic input to the pineal gland, originating from the circadian clock in the suprachiasmatic nucleus, releases norepinephrine. This adrenergic stimulation causes an elevation of cAMP, which is thought to regulate many of the dramatic changes in genes expression known to occur at night. In many aspects, the adrenergic/cAMP effects on gene expression can be recapitulated in primary organ culture. We have analyzed the rat pineal transcriptome at mid-day and mid-night to identify genes that exhibit night/day changes in expression. The pineal transcriptome was compared to that of other rat tissues processed in parallel. In addition, pineal glands were cultured in control conditions, or stimulated with norepinephrine, dibutyryl-cAMP (DBcAMP), or forskolin; the transcriptomes of these glands were then analyzed. Experiment Overall Design: Total RNA was extracted from various rat tissues, and from both in vivo and cultured rat pineal glands, for processing and hybridization to Affymetrix microarrays. Quadruplicates of pooled in vivo pineal glands were analyzed at each timepoint. Single day and night samples of retina, cortex, cerebellum, hypothalamus, liver, and heart were analyzed. Triplicates of control and treated cultured pineal glands were analyzed.
2009-01-27 | E-GEOD-12343 | biostudies-arrayexpress
Project description:Microarray data allowed detection of genes that are induced by light in the zebrafish pineal gland Adult (0.5-1.5 years old) transgenic zebrafish, Tg(aanat2:EGFP)Y8, which express enhanced green fluorescent protein (EGFP) in the pineal gland under the control of the aanat2 regulatory regions, were used. Fish were raised under 12-hr light:12-hr dark (LD) cycles, in a temperature controlled room. Fish were transferred to constant darkness (DD) at the end of the day prior to the experiment. Fish were exposed to a 1-hr light pulse (light intensity of 12 W/m2) prior to sampling (light treatment) or kept under constant darkness for control (dark treatment). The tissues were collected from light- and dark-treated fish at 6 time points with 4-hr intervals throughout one daily cycle, corresponding to CT2, 6, 10, 14, 18 and 22. Fish were anesthetized in 1.5 mM Tricane (Sigma), sacrificed by decapitation, and pineal glands were removed under a fluorescent dissecting microscope. Pools of 12 pineal glands were prepared at each condition and total RNA was extracted using the RNeasy Lipid Tissue Mini Kit (QIAGEN), according to the manufacturer's instructions.
2013-12-14 | E-GEOD-53288 | biostudies-arrayexpress
Project description:Biological processes are optimized by circadian and circannual biological timing systems. In vertebrates, the pineal gland plays an essential role in these systems by converting time into a hormonal signal, melatonin; in all vertebrates, circulating melatonin is elevated at night, independent of lifestyle. We have analyzed the rat pineal transcriptome at mid-day and mid-night to identify genes that exhibit night/day changes in expression. We have also used these data to characterize the non-rhythmic features of the transcriptome that set the pineal gland apart from other tissues by comparing them to the median expression in other rat tissues as found in the Genomics Institute of the Novartis Research Foundation (GNF), Entrez Gene Expression Omnibus (GEO) dataset GDS589. Experiment Overall Design: Rat pineal glands were obtained at mid-day and mid-night for RNA extraction and hybridization to Affymetrix microarrays. Triplicates of pooled pineal glands were analyzed at each timepoint.
2009-01-25 | E-GEOD-12341 | biostudies-arrayexpress