Project description:We performed a circadian RNA expression profile of the mammalian biological clock, the suprachiasmatic nucleus (SCN) in C57/BL6 mice, at 2-hour resolution using microarrays, and at 6-hour resolution using RNA-seq. 24 samples total covering 24 time points, with no replicates. SCN samples from mouse brains collected every 2 hours for 2 days (24 samples total).
Project description:We performed a circadian RNA expression profile of the mammalian biological clock, the suprachiasmatic nucleus (SCN) in C57/BL6 mice, at 2-hour resolution using microarrays, and at 6-hour resolution using RNA-seq. 8 samples total covering 8 time points, with no replicates. SCN samples from mouse brains collected every 6 hours for 2 days (8 samples total).
Project description:To characterize the role of the circadian clock in mouse physiology and behavior, we used RNA-seq and DNA arrays to quantify the transcriptomes of 12 mouse organs over time. We found 43% of all protein coding genes showed circadian rhythms in transcription somewhere in the body, largely in an organ-specific manner. In most organs, we noticed the expression of many oscillating genes peaked during transcriptional “rush hours” preceding dawn and dusk. Looking at the genomic landscape of rhythmic genes, we saw that they clustered together, were longer, and had more spliceforms than nonoscillating genes. Systems-level analysis revealed intricate rhythmic orchestration of gene pathways throughout the body. We also found oscillations in the expression of more than 1,000 known and novel noncoding RNAs (ncRNAs). Supporting their potential role in mediating clock function, ncRNAs conserved between mouse and human showed rhythmic expression in similar proportions as protein coding genes. Importantly, we also found that the majority of best-selling drugs and World Health Organization essential medicines directly target the products of rhythmic genes. Many of these drugs have short half-lives and may benefit from timed dosage. In sum, this study highlights critical, systemic, and surprising roles of the mammalian circadian clock and provides a blueprint for advancement in chronotherapy. 288 samples total covering 12 different tissues, with no replicates. Each tissue sampled every 2 hours for 2 days (24 samples per tissue).
Project description:To characterize the role of the circadian clock in mouse physiology and behavior, we used RNA-seq and DNA arrays to quantify the transcriptomes of 12 mouse organs over time. We found 43% of all protein coding genes showed circadian rhythms in transcription somewhere in the body, largely in an organ-specific manner. In most organs, we noticed the expression of many oscillating genes peaked during transcriptional “rush hours” preceding dawn and dusk. Looking at the genomic landscape of rhythmic genes, we saw that they clustered together, were longer, and had more spliceforms than nonoscillating genes. Systems-level analysis revealed intricate rhythmic orchestration of gene pathways throughout the body. We also found oscillations in the expression of more than 1,000 known and novel noncoding RNAs (ncRNAs). Supporting their potential role in mediating clock function, ncRNAs conserved between mouse and human showed rhythmic expression in similar proportions as protein coding genes. Importantly, we also found that the majority of best-selling drugs and World Health Organization essential medicines directly target the products of rhythmic genes. Many of these drugs have short half-lives and may benefit from timed dosage. In sum, this study highlights critical, systemic, and surprising roles of the mammalian circadian clock and provides a blueprint for advancement in chronotherapy. 96 samples total covering 12 different tissues, with no replicates. Each tissue sampled every 6 hours for 2 days (8 samples per tissue).
Project description:The suprachiasmatic nucleus (SCN) acts as the central clock to coordinate circadian oscillations in mammalian behavior, physiology and gene expression. Despite our knowledge of the circadian transcriptome of the SCN, how it impacts genome-wide protein expression is not well understood. Here, we interrogated the murine SCN proteome across the circadian cycle using SILAC-based quantitative mass spectrometry.
Project description:The aim of this study was to examine the effect of genetic disruption of the circadian clock on gene expression in the cortex across timepoints. Circadian clock protein regulate many critical aspects of cellular function, and Bmal1 knockout mice develop severe neuroinflammation, suggesting a role for circadian clock gene in brain homeostatic function. We compared brain-specific Bmal1 KO mice (Nestin-Cre;Bmal1(flox/flox) with Per1/2 double mutant mice, in order to assess the effects of deletion of the positive and negative limbs of the core clock. 11mo Cre-, NestinCre+/-;Bmal1(fx/fx), or Per1brdm,Per2brdm mice were entrained to 12h light:dark conditions with lights on at 6am for one month, then placed in constant darkness for 24 hours, after which mice were harvested at 6am (CT6) or 6pm (CT18), still in the dark. Mice were anesthetized in the dark, then perfused briefly with PBS+heparin. The brain was then quickly dissected on a cold surface, and the cerebral cortex flash frozen in liquid nitrogen. Cortex samples were mechanically dissociated with a Qiashredder device, then extracted with chloroform and diluted in 70% ethanol. RNA was extracted using Qiagen RNEasy kit according to manufacturers specifications. cDNAs were chemically labeled with Kreatech ULS RNA labeling kit (Kreatech Diagnostics) and Cy5-labeled cDNAs were hybridized to Agilent Mouse v2 4x44K microarrays (G4846A-026655).
Project description:To determine whether immortalized cells derived from the rat SCN (SCN2.2) retain intrinsic rhythm-generating properties characteristic of the SCN, oscillatory properties of the SCN2.2 transcriptome were analyzed and compared to those found in the rat SCN in vivo using rat U34A Affymetrix GeneChips. This SuperSeries is composed of the following subset Series:; GSE1654: Circadian Profiling of the Transcriptome in Immortalized Rat SCN Cells (3 biological replicates); GSE1673: Circadian Profiling of the Transcriptome in Immortalized Rat SCN Cells: Comparison to Long-Evans Rat SCN Experiment Overall Design: Refer to individual Series
Project description:Circadian clocks have evolved as time-measuring molecular devices to help organisms adapt their physiology to daily changes in light and temperature. Cycling transcription has been long hypothesized to account for the wealth of rhythmic protein abundance. However, cyclic degradation signals such as ubiquitylation could shape the rhythmic protein landscape as well. In order to document the circadian ubiquitylated proteome of Drosophila melanogaster, we took advantage of a new means of Ub purification based on in vivo biotinylation of AviTag-tagged ubiquitin by the BirA protein, the bioUb system. NeutrAvidin-bound fractions of head lysates were collected at four circadian times six hours apart and proteins were identified and quantified using a proteomic-based approach.
Project description:The age and sex of studied animals profoundly impacts experimental outcomes in animal-based biomedical research. However, most preclinical studies in mice use a wide-spanning age range from 4 to 14 weeks and do not assess study parameters in male and female mice in parallel. This raises concerns regarding reproducibility and neglect of potentially relevant age and sex differences. Furthermore, the molecular setup of tissues in dependence of age and sex is unknown in naïve mice precluding efficient translational research. Here, we first compared two different mass spectrometric acquisition methods – DDA- and DIA-PASEF – in order to maximize the depth of proteome quantitation. We then employed an optimized workflow of quantitative proteomics based on DIA-PASEF followed by DIA-NN data analysis, and revealed significant differences in mouse paw skin and sciatic nerve (SCN) when comparing (i) male and female mice, and, in parallel, (ii) adolescent mice (4 weeks) with adult mice (14 weeks).