CapStarr-seq: a high-throughput method for quantitative assessment of enhancer activity in mammals
ABSTRACT: Here we developed CapStarr-Seq, a novel high-throughput strategy to quantitatively assess enhancer activity in mammals. This approach couples capture of regions of interest to previously developed Starr-seq technique. Extensive assessment of CapStarr-seq demonstrated accurate quantification of enhancer activity. Furthermore, we found that enhancer strength correlates with binding complexity of tissue-specific transcription factors and super-enhancers, while additive enhancer activity isolates key genes involved in cell identity and function. CapStarr-seq analysis in P5424 cell line (2 replicates), 3T3 cell line and in the plasmid library before (Input) and after transfection
Project description:Exosomes/microvesicles (hereafter referred to as extracellular vesicles) were isolated from the ULF of day 14 cyclic and pregnant ewes using ExoQuick-TC. Extracellular vesicle RNA was pooled (n=4 per status) and analyzed for small RNAs by sequencing on the Ion Torrent PGM platform and analysis with CLC Genomics Workbench small RNA workflow based on the miRBase (Release 19) Bos taurus database. Small RNA analysis of day 14 uterine luminal fluid extracellular vesicles isolated from pregnant and cyclic ewes.
Project description:The IRE1a-XBP1 pathway, a conserved adaptive response to the unfolded protein response, is indispensable for development of the secretory cells. It maintains endoplasmic reticulum homeostasis by enhancing protein folding and the secretory capacity of the cells. Here, we used a modified ChIP-seq protocol (ChIPmentation) to investigate the genome-wide binding events of the transcription factor XBP1 in differentiated mouse Th2 cells.
Project description:We used ATLAS-seq-neo to map the sites of integration of an engineered LINE-1 (L1) retrotransposon into the genome of HeLa S3 cells. In brief, we transfected cells with a plasmid-borne L1.3 element carrying a NeoR-based retrotransposition cassette. Cells were selected by G418 and used to prepare ATLAS-seq-neo libraries. Each sample corresponds to an independent transfection and pool of G418-resistant cells. ATLAS-seq-neo relies on the random mechanical fragmentation of the genomic DNA to ensure high-coverage, ligation of adapter sequences, suppression PCR-amplification of the 3' end L1 junction with its flanking genomic sequence, and Ion Torrent sequencing using single-end 400 bp read chemistry. The primer used for suppression PCR specifically targets the engineered element and not endogenous copies as in the original ATLAS-seq protocol (Philippe et al. eLife 2016).
Project description:We used ATLAS-seq-neo to map the sites of integration of an engineered LINE-1 (L1) retrotransposon into the genome of HeLa S3 cells. In brief, we transfected cells with a plasmid-borne L1.3 element carrying a neomycin-resistance-based retrotransposition cassette, as well as a hygromycin-resistance cassette on the plasmid backbone. For this set of experiments, cells were only selected for transfection (hygromycin) but not for retrotransposition (neomycin). Then we prepared ATLAS-seq-neo libraries. Each sample corresponds to an independent transfection and pool of hygromycin-resistant cells. ATLAS-seq-neo relies on the random mechanical fragmentation of the genomic DNA to ensure high-coverage, ligation of adapter sequences, suppression PCR-amplification of the 3' end L1 junction with its flanking genomic sequence, and Ion Torrent sequencing using single-end 400 bp read chemistry. The primer used for suppression PCR specifically targets the engineered element and not endogenous copies as in the original ATLAS-seq protocol (Philippe et al. eLife 2016). For some libraries, the linker-ligated genomic DNA was digested with BamHI, which cuts downstream of L1 polyA site in the plasmid backbone, to limit amplification from the plasmid and enrich for retrotransposition-mediated insertion events into the genomic DNA.
Project description:Five libraries from 100 HEK293 cells each were prepared using a Smartseq based custom library preparation approach with unique molecular identifiers. One batch of 2 replicates (A) and one batch of 3 replicates (B) were prepared from different cell cultures. Libraries were sequenced on an Ion Proton HEK293 cell (100 cells) 5' selective RNAseq profiling, N4H4 unique molecular identifiers, 2 replicates (A) and 3 replicates (B)
Project description:In this study, we show that by simple modulation of extrinsic signaling pathways, a new class of pluripotent stem cells, referred to as region selective epiblast stem cells (rsEpiSCs), could be efficiently derived from different stages of the early embryo. rsEpiSCs share features of primed pluripotency yet are distinct from EpiSCs in their molecular characteristics and ability to colonize post-implantation embryos. We performed whole-genome bisulfite sequencing (WGBS) experiments to compare the DNA methylation landscapes of conventional EpiSCs and rsEpiSCs. Compare the DNA methylation profiles in 2 pluripotent stem cell types (LP-EpiSCs and conventional EpiSCs) in mouse. Two replicates are examined for each cell type.
Project description:Significant interest has been devoted to the isolation of human pluripotent stem cells displaying the naive state of mouse embryonic stem cells. However, to what extent naive human cells isolated in culture resemble pluripotent cells in vivo remains unclear. Here we present three lines of evidence indicating that naive pluripotent stem cells generated in the absence of transgenes share defining molecular signatures with the human pre-implantation embryo. First, a comprehensive analysis of the transposcriptome reveals that naive human cells have a retroelement expression profile of human cleavage stage embryos. Second, base-resolution mapping of the DNA methylome in naive human cells reveals a genome-wide reduction in CpG and non-CpG methylation levels. Third, female naive cells exhibit an X chromosome status that is similar to that of the human blastocyst. Our work demonstrates that pluripotent stem cells with epigenomic hallmarks of the early human embryo can be directly captured in vitro. Examine the methylomes of 6 naïve, 2 primed and 2 re-primed human embryonic stem cells
Project description:Basal-like and luminal breast tumors have distinct clinical behavior and molecular profiles, yet the underlying mechanisms are poorly defined. To interrogate processes that determine these distinct phenotypes and their inheritance pattern, we generated somatic cell fusions and performed integrated genetic and epigenetic (DNA methylation and chromatin) profiling. We found that the basal-like trait is generally dominant and it is largely defined by epigenetic repression of luminal transcription factors. Definition of super-enhancers highlighted a core program common in luminal cells but high degree of heterogeneity in basal-like breast cancers that correlates with clinical outcome. We also found that protein extracts of basal-like cells is sufficient to induce luminal-to-basal phenotypic switch implying a trigger of basal-like autoregulatory circuits. We determined that KDM6A might be required for luminal-basal fusions, and identified EN1, TBX18, and TCF4 as candidate transcriptional regulators of luminal-to-basal switch. Our findings highlight the remarkable epigenetic plasticity of breast cancer cells. Examination of histone H3K27me3 modifications in various breast cancer cell lines.