Project description:This is a microarray experiment to investigate changes in gene expression in deseeded berries from field grown vines to identify genes involved in diurnal and circadian effects. Changes in gene expression at two time points within a 24 hour cycle were analyzed to identify expression profiles that coincided with diurnal and circadian effects. The gene expression profiles were then to be compared between the two developmental time points T5 v T17). Keywords: Diurnal v Circadian
Project description:The circadian clock is comprised of proteins that form negative feedback loops, which regulate the timing of global gene expression in a coordinated 24 hour cycle. As a result, the plant circadian clock is responsible for regulating numerous physiological processes central to growth and survival. To date, most plant circadian clock studies have relied on diurnal transcriptome changes to elucidate molecular connections between the circadian clock and observable phenotypes in wild-type plants. Here, we have combined high-throughput RNA-sequencing and mass spectrometry to comparatively characterize the lhycca1, prr7prr9, gi and toc1 circadian clock mutant rosette transcriptome and proteome at the end-of-day and end-of-night.
Project description:Circadian rhythms are internal biological rhythms driving temporal tissue-specific, metabolic programs. Loss of the circadian transcription factor BMAL1 in the paraventricular nucleus (PVN) of the hypothalamus reveals its importance in metabolic rhythms, but its functions in individual PVN cells are poorly understood. Here, loss of BMAL1 in the PVN results in arrhythmicity of processes controlling energy balance and alters peripheral diurnal gene expression. BMAL1 chromatin immunoprecipitation sequencing (ChIP-seq) and single-nucleus RNA sequencing (snRNA-seq) reveal its temporal regulation of target genes, including oxytocin (OXT), and restoring circulating OXT peaks in BMAL1-PVN knockout (KO) mice rescues absent activity rhythms. While glutamatergic neurons undergo day/night changes in expression of genes involved in cell morphogenesis, astrocytes and oligodendrocytes show gene expression changes in cytoskeletal organization and oxidative phosphorylation. Collectively, our findings show diurnal gene regulation in neuronal and non-neuronal PVN cells and that BMAL1 contributes to diurnal OXT secretion, which is important for systemic diurnal rhythms.
Project description:Investigation of transcriptome dynamics of Japanese cedar (Cryptomeria japonica) in winter (Dec. 22-23, 2011) and summer (July 30-31, 2012). We investigated seasonal and diurnal transcriptome dynamics of Japanese cedar (Cryptomeria japonica) by analyzing shoot samples collected at four-hour interval for two days in winter and summer, respectively. We first collected sequence data of expressed genes from shoots to designed microarray probes. Microarray analysis revealed the significant difference of transcripts between summer and winter, and the diurnal transcriptome dynamic in summer.Statistical analysis indicated that about 7.7 % of unique genes showed diurnal rhythms with more than two-fold of peak-to-trough amplitude in summer.
Project description:To address whether changes in gene expression in blood cells with sleep loss are different in individuals resistant and sensitive to sleep deprivation (SD). Blood draws every 4 hours during a 3-day study: 24-hour normal baseline, 38 hours of continuous wakefulness and subsequent recovery sleep, for a total of 19 time-points per subject, with every 2-hr psychomotor vigilance test (PVT) assessment when awake. Fourteen subjects who were previously identified as behaviourally resistant (n=7) or sensitive (n=7) to SD by PVT. Intervention consisted of 38 hours continuous wakefulness. We found 4,481 unique genes with a significant 24-hour diurnal rhythm during a normal sleep-wake cycle in blood (false discovery rate [FDR] <5%). Biological pathways were enriched for biosynthetic processes during sleep. After accounting for circadian effects, two genes (SREBF1 and CPT1A, both involved in lipid metabolism) exhibited small, but significant, linear changes in expression with the duration of SD (FDR<5%). The main change with SD was a reduction in the amplitude of the diurnal rhythm of expression of normally cycling probe sets. This reduction was noticeably higher in behaviourally resistant subjects than sensitive subjects, at any given p-value. Furthermore, blood cell type enrichment analysis showed that the expression pattern difference between sensitive and resistant subjects is mainly found in cells of myeloid origin, such as monocytes. Individual differences in behavioural effects of sleep deprivation are associated with differences in diurnal amplitude of gene expression for genes that show circadian rhythmicity.
Project description:Circadian control of gene expression has been established in plants at the transcriptional level, but relatively little is known about circadian control of translation. We used polysome profiling to characterize regulation of transcription and translation over a 24-hour diurnal cycle in Arabidopsis, both in wild type and in plants with a disrupted clock due to constitutive overexpression of the CIRCADIAN CLOCK ASSOCIATED 1 gene (CCA1-ox, AGI AT2G46830).
Project description:Circadian control of gene expression has been established in plants at the transcriptional level, but relatively little is known about circadian control of translation. We used polysome profiling to characterize regulation of transcription and translation over a 24-hour diurnal cycle in Arabidopsis, both in wild type and in plants with a disrupted clock due to constitutive overexpression of the CIRCADIAN CLOCK ASSOCIATED 1 gene (CCA1-ox, AGI AT2G46830).
Project description:RNA polymerase III (pol III) synthesizes short non-coding RNAs, many of which, including tRNAs, Rpph1 RNA, Rn5s rRNA, and Rmrp RNA, are essential for translation. Accordingly, pol III activity is tightly regulated with cell growth and proliferation by factors such as MYC, RB1, TRP53, and MAF1. MAF1 is a repressor of pol III transcription whose activity is controlled by phosphorylation; in particular, it is inactivated through phosphorylation by mTORC1 kinase, a sensor of nutrient availability. Pol III regulation is thus sensitive to environmental cues, yet a diurnal profile of pol III transcription activity is so far lacking. Here we document pol III occupancy of its target genes in mouse liver during the diurnal cycle and show that pol III occupancy rises before the onset of the night, stays high during the night, when mice normally ingest food and when translation is increased, and decreases in daytime. By comparing diurnal pol III occupancy in wild-type mice, arrhythmic mice owing to inactivation of the Arntl gene, mice fed at regular intervals during both night and day, and mice lacking the Maf1 gene, we show that whereas higher pol III occupancy during the night reflects a MAF1-dependent response to feeding, the rise of pol III occupancy before the onset of the night reflects a circadian clock-dependent response. Thus, pol III transcription during the diurnal cycle is regulated both in response to nutrients and by the circadian clock, which allows anticipatory pol III transcription.
Project description:RNA polymerase III (pol III) synthesizes short non-coding RNAs, many of which, including tRNAs, Rpph1 RNA, Rn5s rRNA, and Rmrp RNA, are essential for translation. Accordingly, pol III activity is tightly regulated with cell growth and proliferation by factors such as MYC, RB1, TRP53, and MAF1. MAF1 is a repressor of pol III transcription whose activity is controlled by phosphorylation; in particular, it is inactivated through phosphorylation by mTORC1 kinase, a sensor of nutrient availability. Pol III regulation is thus sensitive to environmental cues, yet a diurnal profile of pol III transcription activity is so far lacking. Here we document pol III occupancy of its target genes in mouse liver during the diurnal cycle and show that pol III occupancy rises before the onset of the night, stays high during the night, when mice normally ingest food and when translation is increased, and decreases in daytime. By comparing diurnal pol III occupancy in wild-type mice, arrhythmic mice owing to inactivation of the Arntl gene, mice fed at regular intervals during both night and day, and mice lacking the Maf1 gene, we show that whereas higher pol III occupancy during the night reflects a MAF1-dependent response to feeding, the rise of pol III occupancy before the onset of the night reflects a circadian clock-dependent response. Thus, pol III transcription during the diurnal cycle is regulated both in response to nutrients and by the circadian clock, which allows anticipatory pol III transcription.