Creation of targeted mutations in the Zebrafish using zinc finger nucleases
Ontology highlight
ABSTRACT:
REPOSITORIES: ENA
Similar Datasets
Project description:Zinc Finger Nucleases (ZFNs) facilitate precise editing of DNA enabling targeted genomic modifications in vivo. ZFNs have been employed to obtain genetically modified plants and animals, and cell-based therapies utilizing ZFNs are undergoing clinical trials. However, many ZFNs display dose-dependent toxicity presumably due to the generation of undesired double stranded breaks at off-target sites within the genome. To evaluate the parameters influencing the functional specificity of ZFNs, we compared the in vivo activity of ZFN variants targeting the zebrafish kdrl locus, which display both high on-target activity and dose-dependent toxicity. We evaluated their functional specificity by assessing lesion frequency at 141 potential off-target sites within the zebrafish genome using Illumina sequencing. Only a minority of these off-target sites displayed significant lesion frequency with kdrl ZFNs. Furthermore, we find that active off-target sites appear to be defined by the thermodynamics of zinc finger-DNA recognition. Surprisingly, we observed that the zinc finger protein specificity and the choice of the engineered dimerization domain of the FokI nuclease could independently influence the fidelity of these ZFNs. The results of this study have implications for the assessment of likely off-target sites within a genome and point to both ZFP-dependent and –independent mechanisms of potential improvement for engineering ZFNs with higher levels of precision. Examined lesions at 141 off-target sites for various treatments of ZFNs and compare to the untreated sample stage 1: raw read but missing quality values stage 2: fastq files available from SRA
2010-08-25 | E-GEOD-23762 | biostudies-arrayexpress
Project description:Zinc Finger Nucleases (ZFNs) facilitate precise editing of DNA enabling targeted genomic modifications in vivo. ZFNs have been employed to obtain genetically modified plants and animals, and cell-based therapies utilizing ZFNs are undergoing clinical trials. However, many ZFNs display dose-dependent toxicity presumably due to the generation of undesired double stranded breaks at off-target sites within the genome. To evaluate the parameters influencing the functional specificity of ZFNs, we compared the in vivo activity of ZFN variants targeting the zebrafish kdrl locus, which display both high on-target activity and dose-dependent toxicity. We evaluated their functional specificity by assessing lesion frequency at 141 potential off-target sites within the zebrafish genome using Illumina sequencing. Only a minority of these off-target sites displayed significant lesion frequency with kdrl ZFNs. Furthermore, we find that active off-target sites appear to be defined by the thermodynamics of zinc finger-DNA recognition. Surprisingly, we observed that the zinc finger protein specificity and the choice of the engineered dimerization domain of the FokI nuclease could independently influence the fidelity of these ZFNs. The results of this study have implications for the assessment of likely off-target sites within a genome and point to both ZFP-dependent and –independent mechanisms of potential improvement for engineering ZFNs with higher levels of precision.
2010-08-25 | GSE23762 | GEO
Project description: Not available
| S-EPMC2502069 | biostudies-literature
Project description:Programmable regulation of gene expression promises to be a powerful therapeutic venue for diseases caused by the misexpression of genes, haploinsufficiencies, or gain of function mutations. While dCas9-effector domain fusions have been used to alter expression levels, their in vivo application is limited by size and immunogenicity. Conversely, the Cys2His2 Zinc Finger domain offers ideal characteristics for in vivo use. However, their intricate engagement with the DNA has made the design of Zinc Finger arrays challenging. We here describe the screening of 49 billion protein-DNA interactions and development of the first deep learning model that solves Zinc Finger design for any genomic target. We demonstrate the versatility of designed Zinc Fingers as nucleases and as activators or repressors by seamlessly reprogramming human transcription factors.
2022-11-01 | GSE215330 | GEO
Project description: Not available
| S-EPMC2674762 | biostudies-literature
Project description:Cys2-His2 zinc finger proteins (ZFPs) are the largest group of transcription factors in higher metazoans. A complete characterization of these ZFPs and their associated target sequences is pivotal to fully annotate transcriptional regulatory networks in metazoan genomes. As a first step in this process, we have characterized the DNA-binding specificities of 130 Zinc finger sets from Drosophila melanogaster using a bacterial one-hybrid system. This data set contains the DNA-binding specificities for at least one encoded ZFP from 71 unique genes and 22 alternate splice isoforms. This represents the largest block of characterized ZFPs from any organism described to date. These recognition motifs can be used to predict genomic binding sites and potential regulatory targets for these factors within the fruit fly genome. We have characterized subsets of fingers from these ZFPs to define the correct orientation and register of the zinc fingers on their defined binding sites. By correlating individual fingers with motif subsites, we can assign finger specificity throughout each ZFP. This reveals the diversity of recognition potential within the naturally-occurring zinc fingers of a single organism, where the characterized fingers can specify 47 of the 64 possible DNA triplets. To confirm the utility of our finger recognition models, we have employed subsets of Drosophila fingers in combination with an existing archive of zinc finger modules to create ZFPs with novel DNA-binding specificity. These finger combinations can be used to create novel functional Zinc Finger Nucleases for editing vertebrate genomes. Illumina sequencing of Barcoded Binding sites obtained after B1H selection of Cys2-His2 zinc finger proteins cloned as a C-terminal fusions to the omega subunit of E. coli RNA polymerase in the B1H system.
2012-12-06 | E-GEOD-42709 | biostudies-arrayexpress
Project description:Programmable nucleases and designer-recombinases are prominent genome editing tools that hold great potential for the treatment of human genetic disorders. However, both of these tools alone are not optimal for clinical applications. We present an approach that combines the ease of targeting of programmable nucleases with editing safety and accuracy of site-specific recombinases. We find that insertional fusions of zinc-finger DNA-binding domains (ZFDs) into the coding sequence of designer-recombinases generate conditional enzymes that are inactive, unless the ZFD binds its target site placed in the vicinity of the recombinase binding site. This induced-fit activity is transferable to a recombinase with relaxed specificity, representing the prototype of a new class of genome editing enzymes that opens exciting perspectives for flexible, seamless, and precise genome surgery.
2023-12-19 | GSE243676 | GEO
Project description:Zinc finger nucleases (ZFN) are powerful tools for editing genes in cells. Here we use ZFNs to interrogate the biological function of human ADPGK, which encodes an ADP-dependent glucokinase (ADPGK), in tumour cell lines. The hypothesis tested is that ADPGK utilises ADP to phosphorylate glucose under conditions where ATP becomes limiting, such as hypoxia. We characterised two ZFN knockout clones in each of two tumour cell lines (H460 and HCT116). All four lines had frameshift mutations in all alleles at the target site in exon 1 of ADPGK, and were ADPGK-null by immunoblotting. ADPGK knockout had little or no effect on cell proliferation, but compromised the ability of H460 cells to survive siRNA silencing of hexokinase-2 under oxic conditions, with clonogenic survival falling from 21±3% for the parental line to 6.4±0.8% (p=0.002) and 4.3±0.8% (p=0.001) for the two knockouts. A similar increased sensitivity to clonogenic cell killing was observed under anoxia. No such changes were found when ADPGK was knocked out in HCT116 cells, for which the parental line was less sensitive than H460 to anoxia and to hexokinase-2 silencing. While knockout of ADPGK in HCT116 cells caused few changes in global gene expression, knockout of ADPGK in H460 cells caused notable up-regulation of mRNAs encoding cell adhesion proteins. Surprisingly, we could discern no effect on glycolysis as measured by glucose consumption or lactate formation under oxic or anoxic conditions, or extracellular acidification rate (Seahorse XF analyser) under oxic conditions in a variety of media. However, oxygen consumption rates were generally lower in the ADPGK knockouts, in some cases markedly so. Collectively, the results demonstrate that ADPGK can contribute to tumour cell survival under conditions of high glycolytic dependence, but the phenotype resulting from knockout of ADPGK is cell line dependent and appears to be unrelated to priming of glycolysis. Use Affymetrix microarrays to examine the effecs of knockout of the gene ADPGK using Zinc Finger nucleases in two cultured cell lines: (i) HCT116 cells (three wild type cultures compared to three ADPGK-knockout cultures), (ii) H460 cells (two wild type cultures compared to two ADPGK-knockout cultures). Ten microarrays in total.
2012-07-19 | E-GEOD-39497 | biostudies-arrayexpress
Project description:Cys2-His2 zinc finger proteins (ZFPs) are the largest group of transcription factors in higher metazoans. A complete characterization of these ZFPs and their associated target sequences is pivotal to fully annotate transcriptional regulatory networks in metazoan genomes. As a first step in this process, we have characterized the DNA-binding specificities of 130 Zinc finger sets from Drosophila melanogaster using a bacterial one-hybrid system. This data set contains the DNA-binding specificities for at least one encoded ZFP from 71 unique genes and 22 alternate splice isoforms. This represents the largest block of characterized ZFPs from any organism described to date. These recognition motifs can be used to predict genomic binding sites and potential regulatory targets for these factors within the fruit fly genome. We have characterized subsets of fingers from these ZFPs to define the correct orientation and register of the zinc fingers on their defined binding sites. By correlating individual fingers with motif subsites, we can assign finger specificity throughout each ZFP. This reveals the diversity of recognition potential within the naturally-occurring zinc fingers of a single organism, where the characterized fingers can specify 47 of the 64 possible DNA triplets. To confirm the utility of our finger recognition models, we have employed subsets of Drosophila fingers in combination with an existing archive of zinc finger modules to create ZFPs with novel DNA-binding specificity. These finger combinations can be used to create novel functional Zinc Finger Nucleases for editing vertebrate genomes.
2012-12-06 | GSE42709 | GEO
Project description:C2H2 zinc finger proteins represent the largest and most enigmatic class of human transcription factors. Their C2H2 arrays are highly variable, indicating that most will have unique DNA binding motifs. However, most of the binding motifs have not been directly determined. We have determined the binding sites and motifs of 119 C2H2 zinc finger proteins and the expression pattern of 80 cell lines overexpressing C2H2 zinc finger proteins in order to study the role of C2H2 zinc finger proteins in gene regulation. We expressed GFP-tagged C2H2-ZF proteins in stable transgenic HEK293 cells. Total RNA was isolated using Trizol and sequencing libraries were constructed using TruSeq Stranded Total RNA Library Prep Kit with Ribo-Zero Gold or TruSeq RNA Library Preparation Kit v2.
2016-10-25 | E-GEOD-76495 | biostudies-arrayexpress