Project description:A goal of a collaboration between the CHDI Foundation and Prof. Jenny Morton at Cambridge University was to identify genes in mice with diurnal/circadian expression patterns. Tissues from wild type mice were harvested every 3 hrs over a 36 hour time period, for a total of 13 time points. Striatal, cortical, hypothalamic and liver samples were harvested, flash frozen, and transferred to Expression Analysis for RNA extraction and miRNA-seq sequencing. Samples passing QC were analyzed to produce high quality, 50-base paired-end RNA-seq results.
Project description:A goal of a collaboration between the CHDI Foundation and Prof. Jenny Morton at Cambridge University was to identify genes in mice with diurnal/circadian expression patterns. Tissues from wild type mice were harvested every 3 hrs over a 36 hour time period, for a total of 13 time points. Striatal, cortical, hypothalamic and liver samples were harvested, flash frozen, and transferred to Expression Analysis for RNA extraction and mRNA-seq sequencing. Samples passing QC were analyzed to produce high quality, 50-base paired-end RNA-seq results.
Project description:This SuperSeries is composed of the following subset Series: GSE40894: The Oscillating miRNA 959-964 cluster impacts Drosophila feeding time and other circadian outputs [expression]. GSE40943: The Oscillating miRNA 959-964 cluster impacts Drosophila feeding time and other circadian outputs [miRNA-seq]. Refer to individual Series
Project description:Using high throughput sequencing of Drosophila head RNA, a small set of miRNAs that undergo robust circadian oscillations in levels were discovered. We concentrated on a cluster of six miRNAs, mir-959-964, all of which peak at about ZT12 or lights-off. The data indicate that the cluster pri-miRNA is transcribed under bona fide circadian transcriptional control and that all 6 mature miRNAs have short half-lives, a requirement for oscillating. Manipulation of food intake dramatically affects the levels and timing of cluster miRNA transcription with no more than minor effects on the core circadian oscillator. This indicates that the central clock regulates feeding, which in turn regulates proper levels and cycling of the cluster miRNAs. Viable Gal4 knock-in as well as cluster knock-out and over-expression strains were used to localize cluster miRNA expression as well as explore their functions. The adult head fat body is a major site of expression, and feeding behavior, innate immunity, metabolism, and perhaps stress responses are under cluster miRNA regulation. The feeding behavior results indicate that there is a feedback circuit between feeding time and cluster miRNA function as well as a surprising role of post-transcriptional regulation in these behaviors and physiology. To address possible functions of the cluster miRNAs, the knock-out strain (mir959-952-KO) as well as a cluster over-expression strain (UAS-cluster, tim-gal4) was assayed for mRNA changes relative to their WT counterparts on Affymetrix expression arrays. The strategy was based on the observation that miRNAs often cause a decrease in the steady-state levels of their target mRNAs (Guo et al., 2010; Lim et al., 2005). Because of the circadian regulation and the possibility of non-fat body expression, the over-expression strain was generated with the broad circadian driver tim-gal4 rather than a fat body driver. To accommodate the possibility that important mRNA changes only appear at certain circadian times, RNA was assayed from heads collected at two different times, ZT4 and ZT16.
Project description:We found that a H3K4 specific histone methyltransferase MLL1, a mammalian homologue of Drosophila trithorax, is essential for circadian transcription. MLL1 is in a complex with CLOCK:BMAL1 and contributes to their rhythmic recruitment to circadian promoters and cyclic H3K4 tri-metylation. To analyze the function of MLL1 on circadian gene regulation, we performed comparative microarray analysis of global gene expression levels in WT and MLL1-deficient MEF, at two different circadian time points (CT18 and CT30). This analysis identified several genes whose expression levels were remarkably changed between CT18 and CT30 in WT and MLL1-KO MEF. Typical clock-regulated genes such as Per2, Per3, Bmal1, or Dbp were found to be changing in WT but not in MLL1-KO MEFs.
Project description:Using high throughput sequencing of Drosophila head RNA, a small set of miRNAs that undergo robust circadian oscillations in levels were discovered. We concentrated on a cluster of six miRNAs, mir-959-964, all of which peak at about ZT12 or lights-off. The data indicate that the cluster pri-miRNA is transcribed under bona fide circadian transcriptional control and that all 6 mature miRNAs have short half-lives, a requirement for oscillating. Manipulation of food intake dramatically affects the levels and timing of cluster miRNA transcription with no more than minor effects on the core circadian oscillator. This indicates that the central clock regulates feeding, which in turn regulates proper levels and cycling of the cluster miRNAs. Viable Gal4 knock-in as well as cluster knock-out and over-expression strains were used to localize cluster miRNA expression as well as explore their functions. The adult head fat body is a major site of expression, and feeding behavior, innate immunity, metabolism, and perhaps stress responses are under cluster miRNA regulation. The feeding behavior results indicate that there is a feedback circuit between feeding time and cluster miRNA function as well as a surprising role of post-transcriptional regulation in these behaviors and physiology. Six samples of small RNA libraries (RNA size 19 to 29 nucleotides long) were prepared from Drosophila heads, each collected at one circadian time point during a light-dark cycle (ZT0, ZT4, ZT8, ZT12, ZT16, ZT20).