Project description:Noncoding RNAs (ncRNAs) comprise an important class of natural regulators that mediate a vast array of biological processes, including the modulation of chromatin architecture. Moreover, artificial ncRNAs have revealed that the functional capabilities of RNA are extremely broad. To further investigate and harness these capabilities, we developed CRISPR-Display ("CRISP-Disp"), a targeted localization strategy that uses Cas9 to deploy large RNA cargos to specific DNA loci. We demonstrate that exogenous RNA domains can be functionally appended onto the CRISPR scaffold at multiple insertion points, allowing the construction of Cas9 complexes with RNAs nearing one kilobase in length, with structured RNAs, protein-binding cassettes, artificial aptamers and pools of random sequences. CRISP-Disp also allows the simultaneous multiplexing of disparate functions at multiple targets. We anticipate that this technology will provide a powerful method with which to ectopically localize functional RNAs and ribonuceloprotein complexes at specified genomic loci. RNA Immunoprecipitation (RIP) against FLAG-tagged Cas9 protein, coexpressed with a large pool of CRISPR RNAs bearing random internal insertions
Project description:Based on the hypothesis that, enhancing the local concentration of donor oligos could increase the correction rates, we generated and tested novel CRISPR-Cas9 systems, in which the DNA repair template is covalently conjugated to Cas9 (RNPD system). To validate our results from the HEK293T reporter cells, we here tested our approach at different endogenous genomic loci and in different cell types. We first targeted the human beta globin (HBB) locus in the K562 cell line, and analyzed correction- and editing frequencies using next generation sequencing (NGS). Next we targeted the Rosa26 and proprotein convertase subtilisin/kexin type 9 (Pcsk9) locus in mouse embryonic stem cells (mESCs). Here, RNPD system was always compared to Cas9 SNAP-tag fusion proteins with uncoupled donor oligos. To also directly compare the engineered RNPD system to the classical CRISPR-Cas9 system, we performed experiments where we used wild-type Cas9 with the uncoupled donor oligos as a control. We therefore targeted the fluorescent reporter locus as well as the endogenous loci HBB, empty spiracles homeobox 1 (EMX1), and C-X-C chemokine receptor type 4 (CXCR4) in HEK293T cells. Finally, we performed the analysis of three computationally predicted off-target sites of the reporter locus.
Project description:We performed a large-scale genome-wide characterisation of indels generated following editing with CRISPR/Cas9. We used pools of sgRNAs and performed targeted capture and sequencing of the edited regions in HepG2 cells.
Project description:CRISPR/Cas9 genome editing was used to disrupt nearly all the GPCR and neuropeptide genes from C. elegans genome. Multiple genes were disrupted in each strain for the purpose of screening. The genotype is the list of targeted genes
Project description:Identifying putative transcription factor target genes by combining CRISPR/Cas9-based transcriptional activation with RNAseq in Drosophila S2R+ cells. This study focuses on the transcription factors Twist and Snail, singly and together. RNA from Drosophila cells following CRISPR/Cas9-based activation of Twist, Snail, or Twist and Snail together, compared with non-targeting sgRNA. Two biological replicates for each experiment
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:We sought to characterise how chromatin states affected CRISPR/Cas9 activity and the induced indel profiles. We used two different doses of Trichostatin and two different doses of a EZH2 inhibitor to modulate the chromatin state and then performed targeted DNA-seq of selected sgRNA target regions to identify the indels.
Project description:The expression level of microRNAs in FLT3-ITD+ AML is unknown. Using empty vector (EV) lentiviral CRISPR-Cas9 infected FLT3-ITD+ AML cell lines (MV4-11 cells), we performed next generation RNA sequencing on small RNAs to determine microRNA expression level in these cells. We found a variety of evolutionarily conserved and non-conserved microRNAs expressed in our cells of interest. Small RNAseq on EV lentiviral CRISPR-Cas9 infected MV4-11 cell lines was performed on triplicate cultures.
Project description:The CRISPR-Cas9 system enables efficient sequence-specific mutagenesis for creating germline mutants of model organisms. Key constraints in vivo remain the expression and delivery of active Cas9-guideRNA ribonucleoprotein complexes (RNPs) with minimal toxicity, variable mutagenesis efficiencies depending on targeting sequence, and high mutation mosaicism. Here, we established in vitro-assembled, fluorescent Cas9-sgRNA RNPs in stabilizing salt solution to achieve maximal mutagenesis efficiency in zebrafish embryos. Sequence analysis of targeted loci in individual embryos reveals highly efficient bi-allelic mutagenesis that reaches saturation at several tested gene loci. Such virtually complete mutagenesis reveals preliminary loss-of-function phenotypes for candidate genes in somatic mutant embryos for subsequent generation of stable germline mutants. We further show efficient targeting of functional non-coding elements in gene-regulatory regions using saturating mutagenesis towards uncovering functional control elements in transgenic reporters and endogenous genes. Our results suggest that in vitro assembled, fluorescent Cas9-sgRNA RNPs provide a rapid reverse-genetics tool for direct and scalable loss-of-function studies beyond zebrafish applications.
Project description:The aim of this experiment was to compare the transcriptomes of SF3B1 mutant and wildtype isogenic cells at the whole cell, nuclear and cytoplasmic levels. Mutations in SF3B1 are often found in the malignant cells of patients suffering from myelodysplastic syndromes and more rarely in other cancer types. The human K-562 leukaemia cell line was modified using CRISPR/Cas9 to integrate an A>G mutation in the SF3B1 consensus coding sequence to change the 700th codon from lysine to glutamic acid (K700E). RNA-Seq was ribo-depleted and randomly primed using SMARTer® Stranded Total RNA Sample Prep Kit. Sequencing used an Illumina NextSeq.