Gene expression analysis of miR-210 over-expressing flies at ZT12.
Ontology highlight
ABSTRACT:
ORGANISM(S): Drosophila melanogaster
PROVIDER: GSE77233 | GEO | 2018/11/13
REPOSITORIES: GEO
Similar Datasets
Project description:MicroRNAs (miRNAs) are a novel class of small RNAs which act as modulators of gene expression either by inhibiting the translation or by inducing the degradation of their target mRNAs. Several studies suggest a role for miRNAs as regulators of the circadian clock in mammals and Drosophila. Based on computational predictions of target mRNAs of clock (or clock related) genes, we have selected the miR-210 as a putative regulator of the period clock gene. We demonstrated that flies over-expressing this miRNA in the canonical clock neurons show an impaired locomotor activity pattern in both light-dark (LD) and constant darkness conditions (DD). Moreover, the projections of the Pigment Dispersing Factor (PDF)-expressing clock neurons in the optic lobe are abnormal showing peculiar “star” shaped body cells. The microarray analysis performed in the adult fly brain, revealed that this miRNA is affecting indirectly the expression of some circadian genes (ie: pdf, npf, cry, tim, pdp1) but not the period gene, and directly genes like echinus and RhoGAp92B. The in-vivo down regulation of echinus indeed can be associated with a severe impairment of the locomotor activity of flies, while the GTPase RhoGAP92B, important for the regulation of the cellular shape of neurons, could be involved in the morphological development of the PDF-expressing neurons.
2018-11-13 | GSE76099 | GEO
Project description:Single microRNAs are usually associated with hundreds of putative target genes that can influence multiple phenotypic traits in Drosophila, ranging from development to behaviour. We investigated the function of Drosophila miR-210 in circadian behaviour by misexpressing it within circadian clock cells. Manipulation of miR-210 expression levels in the PDF (pigment dispersing factor) positive neurons affected the phase of locomotor activity, under both light-dark conditions and constant darkness. PER cyclical expression was not affected in clock neurons, however, when miR-210 was up-regulated, a dramatic alteration in the morphology of PDF ventral lateral neuron (LNv) arborisations was observed. The effect of miR-210 in shaping neuronal projections was confirmed in vitro, using a Drosophila neuronal cell line. A transcriptomic analysis revealed that miR-210 overexpression affects the expression of several genes belonging to pathways related to circadian processes, neuronal development, GTPases signal transduction and photoreception. Collectively, these data reveal the role of miR-210 in modulating circadian outputs in flies and guiding/remodelling PDF positive LNv arborisations and indicate that miR-210 may have pleiotropic effects on the clock, light perception and neuronal development.
2018-11-13 | GSE77245 | GEO
Project description:Chromatin organization plays a crucial role in gene regulation by controlling the accessibility of DNA to transcription machinery. While significant progress has been made in understanding the regulatory role of clock proteins in circadian rhythms, how chromatin organization affects circadian rhythms remains poorly understood. Here, we employed ATAC-seq (Assay for Transposase-Accessible Chromatin with Sequencing) on FAC-sorted Drosophila clock neurons to assess genome-wide chromatin accessibility at dawn and dusk over the circadian cycle. We observed significant oscillations in chromatin accessibility at promoter and enhancer regions of hundreds of genes, with enhanced accessibility either at dusk or dawn, which correlated with their peak transcriptional activity. Notably, genes with enhanced accessibility at dusk were enriched with E-box motifs, while those more accessible at dawn were enriched with VRI/PDP1-box motifs, indicating that they are regulated by the core circadian feedback loops, PER/CLK and VRI/PDP1, respectively. Further, we observed a complete loss of chromatin accessibility rhythms in per01 null mutants, with chromatin consistently accessible at both dawn and dusk, underscoring the critical role of Period protein in driving chromatin compaction during the repression phase at dawn. Together, this study demonstrates the significant role of chromatin organization in circadian regulation, revealing how the interplay between clock proteins and chromatin structure orchestrates the precise timing of biological processes throughout the day. This work further implies that variations in chromatin accessibility might play a central role in the generation of diverse circadian gene expression patterns in clock neurons.
2024-03-05 | GSE256533 | GEO
Project description:To compare circadian gene expression within highly discrete neuronal populations, we separately purified and characterized two adjacent but distinct groups of Drosophila adult circadian neurons: the 8 small and 10 large PDF (pigment-dispersing factor)-expressing ventral lateral neurons (s-LNvs and l-LNvs, respectively). The s-LNvs are the principal circadian pacemaker cells, whereas recent evidence indicates that the l-LNvs are involved in sleep and light-mediated arousal. Although half of the l-LNv-enriched mRNA population including core clock mRNAs is shared between the l-LNvs and s-LNvs, the other half is l-LNv- and s-LNv specific. The distribution of four specific mRNAs is consistent with prior characterization of the four encoded proteins and therefore indicates successful purification of the two neuronal types. Moreover, an octopamine receptor mRNA is selectively enriched in l-LNvs, and only these neurons respond to in vitro application of octopamine. Dissection and purification of l-LNvs from flies collected at different times indicate that these neurons contain cycling clock mRNAs with higher circadian amplitudes as well as at least a 10-fold higher fraction of oscillating mRNAs than all previous analyses of head RNA. Many of these cycling l-LNv mRNAs are well-expressed but do not cycle or cycle much less well elsewhere in heads. The results suggest that RNA cycling is much more prominent in circadian neurons than elsewhere in heads and may be particularly important for the functioning of these neurons.
2010-07-15 | GSE22308 | GEO
Project description:To compare circadian gene expression within highly discrete neuronal populations, we separately purified and characterized two adjacent but distinct groups of Drosophila adult circadian neurons: the 8 small and 10 large PDF (pigment-dispersing factor)-expressing ventral lateral neurons (s-LNvs and l-LNvs, respectively). The s-LNvs are the principal circadian pacemaker cells, whereas recent evidence indicates that the l-LNvs are involved in sleep and light-mediated arousal. Although half of the l-LNv-enriched mRNA population including core clock mRNAs is shared between the l-LNvs and s-LNvs, the other half is l-LNv- and s-LNv specific. The distribution of four specific mRNAs is consistent with prior characterization of the four encoded proteins and therefore indicates successful purification of the two neuronal types. Moreover, an octopamine receptor mRNA is selectively enriched in l-LNvs, and only these neurons respond to in vitro application of octopamine. Dissection and purification of l-LNvs from flies collected at different times indicate that these neurons contain cycling clock mRNAs with higher circadian amplitudes as well as at least a 10-fold higher fraction of oscillating mRNAs than all previous analyses of head RNA. Many of these cycling l-LNv mRNAs are well-expressed but do not cycle or cycle much less well elsewhere in heads. The results suggest that RNA cycling is much more prominent in circadian neurons than elsewhere in heads and may be particularly important for the functioning of these neurons. Gene expression was profiled in purified large PDF neurons across 4 time-points and small PDF neurons at two time-points under an LD cycle. Circadian neurons (PDF large and small cells), general neurons (ELAV) and per01:large PDF cells were labeled by GFP using specfic drivers. Expression of these cells types were profiled after manual cell sorting of GFP-positive cells at different time-points under a light/dark (LD) cycle. The time-points included ZT0, ZT6, ZT12, and ZT18 in the case of large PDF cells, and ZT0 and ZT12 in the case of small PDF cells, ELAV cells and per01:large PDF cells. 3 biological replicates were collected for the large PDF cells and ELAV cells at ZT0 and ZT12. 2 replicates were collected for large PDF cells at ZT6 and ZT18, small PDF cells, and per01:large PDF cells.
2010-07-15 | E-GEOD-22308 | biostudies-arrayexpress
Project description:The Drosophila circadian clock is driven by a transcriptional feedback loop in which the bHLH transcription factor CLOCK-CYCLE (CLK-CYC) binds E-boxes to transcribe genes encoding the PERIOD-TIMELESS (PER-TIM) repressor, which releases CLK-CYC from E-boxes to inhibit transcription. The bHLH-Orange transcription factor CLOCKWORK ORANGE (CWO) reinforces repression by binding E-boxes to displace CLK-CYC, but also acts through an unknown mechanism to promote CLK-CYC transcription. To determine how CWO activates CLK-CYC transcription, we identified CWO DNA binding targets that are upregulated in the absence of CWO repression, conserved in mammals and preferentially expressed in brain pacemaker neurons. Among the genes identified was the Drosophila ortholog of mammalian Clock Interacting Protein Circadian (Cipc) that acts to repress CLOCK-BMAL1 transcription. Reducing or eliminating Drosophila Cipc expression shortens circadian period while overexpressing Cipc lengthens circadian period in flies, consistent with previous analysis showing that Drosophila Cipc represses CLK-CYC transcription in S2 cell culture. Long period rhythms of cwo mutant flies are largely rescued when Cipc expression is reduced or eliminated, indicating that increased Cipc expression mediates period lengthening of cwo mutants. These results suggest a mechanism for CWO-dependent CLK-CYC activation: CWO inhibition of CIPC repression promotes CLK-CYC transcription. Such a mechanism may be conserved given that orthologs of cwo and Cipc carry out analogous roles in the mammalian circadian clock.
2021-07-23 | GSE165043 | GEO
Project description:Circadian rhythms time physiological and behavioral processes to 24-hour cycles. It is generally assumed that most cells contain self-sustained circadian clocks that drive circadian rhythms in gene expression that ultimately generating circadian rhythms in physiology. While those clocks supposedly act cell autonomously, current work suggests that in Drosophila some of them can be adjusted by the brain circadian pacemaker through neuropeptides, like the Pigment Dispersing Factor (PDF). Despite these findings and the ample knowledge of the molecular clockwork, it is still unknown how circadian gene expression in Drosophila is achieved across the body . Here, we used single-cell and bulk RNAseq data to identify cells within the fly that express core-clock components. Surprisingly, we found that less than a third of the cell types in the fly are enriched for core-clock genes. Moreover, we identified Lamina wild field (Lawf) and Ponx-neuro positive (Poxn) neurons as putative new circadian neurons. In addition, we found several cell types that don’t express core clock components but are highly enriched for cyclically expressed mRNAs. Strikingly, these cell types express the PDF receptor (Pdfr), suggesting that PDF drives rhythmic gene expression in many cell types in flies. Other cell types express both core circadian clock components and Pdfr, suggesting that in these cells, PDF regulates the phase of rhythmic gene expression. Together, our data suggest three different mechanisms generate daily gene expression in cells and tissues: an endogenous canonical molecular clock, PDF signaling-driven expression, or a combination of both.
2023-06-14 | GSE233184 | GEO
Project description:The transcription factor Mef2 regulates activity-dependent neuronal plasticity and morphology in mammals, and clock neurons are reported to experience activity-dependent circadian remodeling in Drosophila. We show here that Mef2 is required for this daily fasciculation-defasciculation cycle. Moreover, the master circadian transcription complex CLK/CYC directly regulates Mef2 transcription. ChIP-Chip analysis identified numerous Mef2 target genes implicated in neuronal plasticity, including the cell-adhesion gene Fas2. Genetic epistasis experiments support this transcriptional regulatory hierarchy, CLK/CYC->Mef2-> Fas2, indicate that it influences the circadian fasciculation cycle within pacemaker neurons and suggest that this cycle also contributes to circadian behavior. Mef2 therefore transmits clock information to machinery involved in neuronal remodeling, which contributes to locomotor activity rhythms. Mef2 ChIP-chip samples collected at 6 timepoints, input and IP samples
2013-05-03 | E-GEOD-46576 | biostudies-arrayexpress
Project description:The timing of behavior under natural light-dark conditions is a function of circadian clocks and photic input pathways. Yet a mechanistic understanding of how these pathways collaborate in animals is lacking. Here we demonstrate in Drosophila that the Phosphatase of Regenerating Liver-1 (PRL-1) sets period length and behavioral phase gated by photic signals. PRL-1 knockdown in PDF clock neurons dramatically lengthens circadian period. PRL-1 mutants exhibit allele-specific interactions with the light- and clock-regulated gene timeless (tim). Moreover, we show that PRL-1 promotes TIM accumulation and dephosphorylation. Interestingly, the PRL-1 mutant period lengthening is suppressed in constant light and PRL-1 mutants display a delayed phase under short, but not long, photoperiod conditions. Thus, our studies reveal that PRL-1 dependent dephosphorylation of TIM is a core mechanism of the clock that sets period length and phase in darkness, enabling the behavioral adjustment to changing day-night cycles.
2020-11-11 | PXD020986 | Pride
Project description:The transcription factor Mef2 regulates activity-dependent neuronal plasticity and morphology in mammals, and clock neurons are reported to experience activity-dependent circadian remodeling in Drosophila. We show here that Mef2 is required for this daily fasciculation-defasciculation cycle. Moreover, the master circadian transcription complex CLK/CYC directly regulates Mef2 transcription. ChIP-Chip analysis identified numerous Mef2 target genes implicated in neuronal plasticity, including the cell-adhesion gene Fas2. Genetic epistasis experiments support this transcriptional regulatory hierarchy, CLK/CYC->Mef2-> Fas2, indicate that it influences the circadian fasciculation cycle within pacemaker neurons and suggest that this cycle also contributes to circadian behavior. Mef2 therefore transmits clock information to machinery involved in neuronal remodeling, which contributes to locomotor activity rhythms.
2013-05-03 | GSE46576 | GEO