Project description:The experiments are done with three libraries by introducing base-pair perturbations on Widom 601: (1) poly(dA:dT) tract library (2) mismatch library (3) insertion library. And additional two more libraries based on native yeast genomic sequences: (4) Park97 mismatch library (5) Park97 insertion library. And we measured the nucleosome positioining in the base-pair resolution for before and after sliding by Chd1 chromatin remodeler.
Project description:Altered DNA methylation is a crucial epigenetic event in hepatocellular carcinoma (HCC) development and progression. Through methylation-transcriptomic analysis, we identified a set of sixty potential DNA methylation-based epidriver genes. This set of genes focuses on the hypermethylation of EMX1, which is frequently observed in hepatobiliary tumors. Despite of its frequent occurrence, the function of EMX1 remains largely unknown. By utilizing bisulfite-next-generation sequencing, we have detected EMX1 DNA hypermethylation on the gene body, which is positively correlated with EMX1 mRNA expression. Further analysis revealed that EMX1 mRNA terminal exon splicing in HCC generated two protein isoforms: EMX1 full length (EMX1-FL) and alternative terminal exon splicing isoform (EMX1-X1). Cellular functional assays demonstrated that gain-of-function EMX1-FL, but not EMX1-X1, induced HCC cells migration and invasion while silencing EMX1-FL inhibited HCC cells motility. This result was further validated by in vivo tumor metastasis models. Mechanistically, EMX1-FL bound to EGFR promoter, promoting EGFR transcription and activating EGFR-ERK signaling to trigger tumor metastasis. Therefore, EGFR may be a potential therapeutic target for EMX1-high expression HCC. Our work illuminated the crucial role of gene body hypermethylation-activated EMX1-FL in promoting tumorigenesis and metastasis in HCC. These findings pave the way for targeting the EMX1-EGFR axis in HCC tumorigenicity and metastasis.
Project description:By a robust unbiased ChIP-seq approach, we demonstrated that CRISPR/Cas9 had crRNA-specific off-target binding activities in human genome. However, most of those binding off-targets could not be efficiently cleaved both in vivo and in vitro which suggested the cleavage off-target activity of CRISPR/Cas9 in human genome is very limited. We provided a valuable tool to further investigate the molecular mechanism of CRISPR/Cas9 and to optimize its in vivo targeting sgRNA binding sites were identified with ChipSeq by using GFP antibody (there are 2 replicates for egfa-t1 sgRNA,emx1 sgRNA and control without sgRNA in Hek293T cells, one egfa-t1 sgRNA,emx1 sgRNA and control without sgRNA in HeLaS3 cells)
Project description:The bacterial CRISPR-Cas9 system has been widely adapted for RNA-guided genome editing and gene regulation in diverse organisms yet its in vivo target specificity is poorly understood. Here we provide the first genome-wide binding maps of nuclease-deactivated Cas9 loaded with guide RNAs in mammalian cells. We find a 5-nucleotide seed region in the guide RNA targets Cas9 to thousands of sites in the genome. Chromatin accessibility limits binding to the other hundreds of thousands sites with matching seed sequences, and consequently 70% of off-target binding sites are associated with genes. U-rich seeds have low numbers of off-target sites limited by both low guide RNA abundance and scarcity of complimentary sites in accessible chromatin. Unexpectedly, off-target sites show little evidence of cleavage, supporting a two-state model reminiscent of eukaryotic RNAi machinery where a short seed match triggers binding but extensive pairing is required for cleavage. ChIP-seq of HA-dCas9 loaded with 4 sgRNAs (Phc1-sg1, Phc1-sg2, Nanog-sg2, and Nanog-sg3) in mouse, and 2 sgRNAs in human (EMX1-sg1 and EMX1-sg3)
Project description:the goal of the study was to compare gene expression between control and Pbx1; Emx1-cre mutant corteces at e15.5 E15.5 whole cortex was dissected for the analysis. Control embryo genotype was Pbx1F/+. Mutant embryo genotype was Pbx1F/-; Emx1-cre. 4 corteces of each genotype were used for the analysis: 4 controls and 4 mutants, 8 samples total.
Project description:the goal of the study was to compare gene expression between control and Pbx1; Emx1-cre mutant corteces at e12.5 E12.5 whole cortex was dissected for the analysis. Control embryo genotype was Pbx1F/+. Mutant embryo genotype was Pbx1F/-; Emx1-cre. 4 corteces of each genotype were used for the analysis: 4 controls and 4 mutants, 8 samples total.
Project description:To determine the genes regulated by Fezf2 during neocortical development, we performed RNA-seq on Fezf2 +/+; Emx1-cre (Fezf2 wildtype) and Fezf2 fl/+; Emx1-Cre (Fezf2 Knockout) neocortices isolated from the P0 mice. After RNA isolation from the dissected tissue the samples were processed for library preperation using Illumina Poly-A RNA kit. Fezf2 can reprogram the upper layer neocortical neurons to form corticospinal tract. To understand the key transcriptomic changes driven by Fezf2 that drive this reprogramming, we performed in RNA-seq on the cells over-expressing Fezf2 and Gfp or Gfp. At E15.5, in utero electroporations targeting cortical plate, were performed in pregnant mice with Fezf2 and Gfp plasmids or with Gfp plasmid alone, which was used as control. At P3, the Gfp positive cells were FAC sorted from Fezf2 and Gfp, or Gfp cortices and processed for library preparations using NUGEN Ovation® V2 system. Libraries were sequenced using Illumina 2000 platform to generate 75bp single reads. At least 10 million uniquely mapped reads were obtained for each sample. To determine the genes directly regulated by FEZF2, we performed the ChIP-Seq on N2A cells that were transfected to over express FEZF2 using pCAG- Fezf2-V5 and pCAG-V5. After 48 hr, of transfection, cells were fixed and processed for ChIP seq. Libraries were prepared using Illumina TruSeq ChIP Libary Preparation Kit.