Project description:We performed ChIP-seq of two core circadian TFs which were found to be important in leukemia proliferation, in order to identify potential target genes regulated by the circadian rhythm. Here, we performed ChIP-seq for the core circadian transcription factors CLOCK and ARNTL (BMAL1) in NOMO-1 and THP-1 cells.
Project description:Molecular analysis of circadian rhythm in mice. Liver tissue of wildtype, Clock mutant and Cry deficient C57BL/6 8- to 10-week-old male mice examined. Keywords = circadian rhythm Keywords: other
Project description:Mammalian circadian rhythm is established by the negative feedback loops consisting of a set of clock genes, which lead to the circadian expression of thousands of downstream genes. As genome-wide transcription is organized under the high-order chromosome structure, it is unclear how circadian gene expression is influenced by chromosome structure. In this study, we focus on the function of chromatin structure proteins cohesin as well as CTCF (CCCTC-binding factor) in circadian rhythm. We analyzed the interactome of a Bmal1-bound enhancer upstream of a clock gene, Nr1d1, by 4C-seq and observed that cohesin binding sites are enriched in the interactome. Integrating circadian transcriptome data and cistrome data, we found that cohesin-CTCF co-binding sites tend to insulate the phases of circadian oscillating genes while cohesin-non-CTCF sites facilitate the interaction between circadian enhancer and promoter. A coarse-grained model integrating the long-range effect of cohesin and CTCF markedly improved our mechanistic understanding of circadian gene expression. This model is subsequently supported by our RNA-seq data from cohesin knockout cells. Cohesin is required at least in part for driving the circadian gene expression by facilitating the enhancer-promoter looping. Taken together, our study provided a novel insight into the relationship between circadian transcriptome and the high-order chromosome structure. Bmal1 ChIP-Seq in WT mouse embryonic fibroblast cells
Project description:Identification of cyclical expressed coding and non-coding genes during the circadian rhythm in NIH3T3 cells. NIH3T3 cells were synchronized for their circadian rhythm and RNA sequencing were performed at several time points along the rhythm. This data was used to identify cyclical expressed genes as well as long intergenic non-coding RNAs.
Project description:Identification of cyclical expressed coding and non-coding genes during the circadian rhythm in NIH3T3 cells. NIH3T3 cells were synchronized for their circadian rhythm and RNA sequencing were performed at several time points along the rhythm. This data was used to identify cyclical expressed genes as well as long intergenic non-coding RNAs. NIH3T3 cells were synchronized with 100 nM Dexamethasone for 2 hours, then medium was changed to normal culture medium (0h). Every 4 hours cells were harvested, RNA isolated and RNAseq performed.
Project description:Using larval zebrafish as a model system, we applied a genome-wide transcriptome approach that allowed us to investigate circadian gene expression that can be associated with various tissues and cell types. Our analysis of circadian gene regulatory network revealed a general principle: circadian clock controls diverse aspects of circadian physiology through transcriptional cascade of transcription factors (TFs). As a proof of this principle, we focused on microphthalmia-associated transcription factor a (mitfa), a dark-induced TF controlling melanogenesis in melanocytes. We demonstrated experimentally that there is a circadian rhythm of melanin synthesis mediated by mitfa. The circadian rhythm of mitfa is in turn driven by both endogenous clock and external light/dark cycle. The circadian rhythm of melanin synthesis may play an important role in zebrafish’s adaptation to daily cycle of lighting condition in the environment.