scholarly journals beditor: A computational workflow for designing libraries of guide RNAs for CRISPR-mediated base editing

2018 ◽  
Author(s):  
Rohan Dandage ◽  
Philippe C Després ◽  
Nozomu Yachie ◽  
Christian R Landry
Keyword(s):  
A Priori ◽  
Maximum Activity ◽  
Base Editing ◽  
Guide Rna ◽  
Guide Rnas ◽  
Genome Wide ◽  
Disease Mutations ◽  
Computational Workflow ◽  
Activity Window ◽  
Target Effects

ABSTRACTCRISPR-mediated base editors have opened unique avenues for scar-free genome-wide mutagenesis. Here, we describe a comprehensive computational workflow called beditor that can be broadly adapted for designing guide RNA libraries with a range of CRISPR-mediated base editors, PAM recognition sequences and genomes of many species. Additionally, in order to assist users in selecting the best sets of guide RNAs for their experiments, a priori estimates, called beditor scores are calculated. These beditor scores are intended to select guide RNAs that conform to requirements for optimal base editing: the editable base falls within maximum activity window of the CRISPR-mediated base editor and produces non-confounding mutational effects with minimal predicted off-target effects. We demonstrate the utility of the software by designing guide RNAs for base-editing to create or remove thousands of clinically important human disease mutations.

scholarly journals Improving the Precision of Base Editing by Bubble Hairpin Single Guide RNA

mBio ◽  
2021 ◽  
Vol 12 (2) ◽  
Author(s):  
Zhiwei Hu ◽  
Yannan Wang ◽  
Qian Liu ◽  
Yan Qiu ◽  
Zhiyu Zhong ◽  
...  
Keyword(s):  
Genome Editing ◽  
Dna Breaks ◽  
Single Nucleotide ◽  
Base Editing ◽  
Guide Rna ◽  
Guide Rnas ◽  
Double Stranded Dna ◽  
Target Sites ◽  
Guide Sequence ◽  
Sgrna Design

ABSTRACT Base editing is a powerful genome editing approach that enables single-nucleotide changes without double-stranded DNA breaks (DSBs). However, off-target effects as well as other undesired editings at on-target sites remain obstacles for its application. Here, we report that bubble hairpin single guide RNAs (BH-sgRNAs), which contain a hairpin structure with a bubble region on the 5′ end of the guide sequence, can be efficiently applied to both cytosine base editor (CBE) and adenine base editor (ABE) and significantly decrease off-target editing without sacrificing on-target editing efficiency. Meanwhile, such a design also improves the purity of C-to-T conversions induced by base editor 3 (BE3) at on-target sites. Our results present a distinctive and effective strategy to improve the specificity of base editing. IMPORTANCE Base editors are DSB-free genome editing tools and have been widely used in diverse living systems. However, it is reported that these tools can cause substantial off-target editings. To meet this challenge, we developed a new approach to improve the specificity of base editors by using hairpin sgRNAs with a bubble. Furthermore, our sgRNA design also dramatically reduced indels and unwanted base substitutions at on-target sites. We believe that the BH-sgRNA design is a significant improvement over existing sgRNAs of base editors, and our design promises to be adaptable to various base editors. We expect that it will make contributions to improving the safety of gene therapy.

scholarly journals Improved analysis of CRISPR fitness screens and reduced off-target effects with the BAGEL2 gene essentiality classifier

2020 ◽  
Author(s):  
Eiru Kim ◽  
Traver Hart
Keyword(s):  
Dynamic Range ◽  
Quality Data ◽  
Loss Of Function ◽  
Genetic Screens ◽  
Gene Essentiality ◽  
Guide Rna ◽  
Genome Wide ◽  
Improved Model ◽  
Target Effects

AbstractIdentifying essential genes in genome-wide loss of function screens is a critical step in functional genomics and cancer target finding. We previously described the Bayesian Analysis of Gene Essentiality (BAGEL) algorithm for accurate classification of gene essentiality from short hairpin RNA and CRISPR/Cas9 genome wide genetic screens. Here, we introduce an updated version, BAGEL2, which employs an improved model that offers greater dynamic range of Bayes Factors, enabling detection of tumor suppressor genes, and a multi-target correction that reduces false positives from off-target CRISPR guide RNA. We also suggest a metric for screen quality at the replicate level and demonstrate how different algorithms handle lower-quality data in substantially different ways. BAGEL2 is written in Python 3 and source code, along with all supporting files, are available on github (https://github.com/hart-lab/bagel).

scholarly journals beditor: A Computational Workflow for Designing Libraries of Guide RNAs for CRISPR-Mediated Base Editing

Genetics ◽  
2019 ◽  
Vol 212 (2) ◽  
pp. 377-385 ◽  
Author(s):  
Rohan Dandage ◽  
Philippe C. Després ◽  
Nozomu Yachie ◽  
Christian R. Landry
Keyword(s):  
Base Editing ◽  
Guide Rnas ◽  
Computational Workflow

scholarly journals kRISP-meR: A Reference-free Guide-RNA Design Tool for CRISPR/Cas9

2019 ◽  
Author(s):  
Mahmudur Rahman Hera ◽  
Amatur Rahman ◽  
Atif Rahman
Keyword(s):  
Genome Editing ◽  
Design Tool ◽  
Target Region ◽  
Guide Rna ◽  
Guide Rnas ◽  
Rna Design ◽  
Reference Genomes ◽  
Target Effects

AbstractGenome editing using the CRISPR/Cas9 system requires designing guide RNAs (sgRNA) that are efficient and specific. Guide RNAs are usually designed using reference genomes which limits their use in organisms with no or incomplete reference genomes. Here, we present kRISP-meR, a reference free method to design sgRNAs for CRISPR/Cas9 system. kRISP-meR takes as input a target region and sequenced reads from the organism to be edited and generates sgRNAs that are likely to minimize off-target effects. Our analysis indicates that kRISP-meR is able to identify majority of the guides identified by a widely used sgRNA designing tool, without any knowledge of the reference, while retaining specificity.

scholarly journals Prime editing for functional repair in patient-derived disease models

2020 ◽  
Author(s):  
Imre F. Schene ◽  
Indi P. Joore ◽  
Rurika Oka ◽  
Michal Mokry ◽  
Anke H.M. van Vugt ◽  
...  
Keyword(s):  
Adult Stem Cells ◽  
Gene Editing ◽  
Therapeutic Potential ◽  
Gene Encoding ◽  
Base Editing ◽  
Homology Directed Repair ◽  
Genome Wide ◽  
Culture Models ◽  
Liver Organoids ◽  
Target Effects

AbstractPrime editing is a novel genome editing technology using fusion proteins of Cas9-nickase and reverse transcriptase, that holds promise to correct the vast majority of genetic defects. We develop prime editing for primary adult stem cells grown in organoid culture models. First, we generate precise in-frame deletions in the gene encoding ß-catenin (CTNNB1) that result in proliferation independent of Wnt-stimuli, mimicking a mechanism of the development of liver cancer. Moreover, prime editing functionally recovers diseasecausing mutations in intestinal organoids from patients with DGAT1-deficiency and liver organoids from a patient with Wilson disease (ATP7B). Prime editing is as efficient in 3D grown organoids as in 2D grown cell lines and offers greater precision than Cas9-mediated homology directed repair (HDR). Base editing remains more reliable than prime editing but is restricted to a subgroup of pathogenic mutations. Whole-genome sequencing of four prime-edited clonal organoid lines reveals absence of genome-wide off-target effects underscoring therapeutic potential of this versatile and precise gene editing strategy.

scholarly journals dbGuide: A database of functionally validated guide RNAs for genome editing in human and mouse cells

2020 ◽  
Author(s):  
Alexander A. Gooden ◽  
Christine N. Evans ◽  
Timothy P. Sheets ◽  
Michelle E. Clapp ◽  
Raj Chari
Keyword(s):  
Epigenetic Modification ◽  
Gene Activation ◽  
Amplicon Sequencing ◽  
Ease Of Use ◽  
Rna Sequences ◽  
Additional Species ◽  
Base Editing ◽  
Guide Rna ◽  
Guide Rnas ◽  
Human And Mouse

ABSTRACTWith the technology’s accessibility and ease of use, CRISPR has been employed widely in many different organisms and experimental settings. As a result, thousands of publications have used CRISPR to make specific genetic perturbations, establishing in itself a resource of validated guide RNA sequences. While numerous computational tools to assist in the design and identification of candidate guide RNAs exist, these are still just at best predictions and generally, researchers inevitably will test multiple sequences for functional activity. Here, we present dbGuide (https://sgrnascorer.cancer.gov/dbguide), a database of functionally validated guide RNA sequences for CRISPR/Cas9-based knockout in human and mouse. Our database not only contains computationally determined candidate guide RNA sequences, but of even greater value, over 4000 sequences which have been functionally validated either through direct amplicon sequencing or manual curation of literature from over 1000 publications. Finally, our established framework will allow for continual addition of newly published and experimentally validated guide RNA sequences for CRISPR/Cas9-based knockout as well as incorporation of sequences from different gene editing systems, additional species, and other types of site-specific functionalities such as base editing, gene activation, repression, and epigenetic modification.

scholarly journals In vivo CRISPR-Cas gene editing with no detectable genome-wide off-target mutations

2018 ◽  
Author(s):  
Pinar Akcakaya ◽  
Maggie L. Bobbin ◽  
Jimmy A. Guo ◽  
Jose M. Lopez ◽  
M. Kendell Clement ◽  
...  
Keyword(s):  
Genome Editing ◽  
Ex Vivo ◽  
Strong Support ◽  
Guide Rna ◽  
Genome Wide ◽  
Highly Sensitive ◽  
Further Development ◽  
Target Effects ◽  
Cas Gene

CRISPR-Cas genome-editing nucleases hold substantial promise for human therapeutics1–5 but identifying unwanted off-target mutations remains an important requirement for clinical translation6, 7. For ex vivo therapeutic applications, previously published cell-based genome-wide methods provide potentially useful strategies to identify and quantify these off-target mutation sites8–12. However, a well-validated method that can reliably identify off-targets in vivo has not been described to date, leaving the question of whether and how frequently these types of mutations occur. Here we describe Verification of In Vivo Off-targets (VIVO), a highly sensitive, unbiased, and generalizable strategy that we show can robustly identify genome-wide CRISPR-Cas nuclease off-target effects in vivo. To our knowledge, these studies provide the first demonstration that CRISPR-Cas nucleases can induce substantial off-target mutations in vivo, a result we obtained using a deliberately promiscuous guide RNA (gRNA). More importantly, we used VIVO to show that appropriately designed gRNAs can direct efficient in vivo editing without inducing detectable off-target mutations. Our findings provide strong support for and should encourage further development of in vivo genome editing therapeutic strategies.

scholarly journals Prime editing for functional repair in patient-derived disease models

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Imre F. Schene ◽  
Indi P. Joore ◽  
Rurika Oka ◽  
Michal Mokry ◽  
Anke H. M. van Vugt ◽  
...  
Keyword(s):  
Adult Stem Cells ◽  
Gene Editing ◽  
Therapeutic Potential ◽  
Gene Encoding ◽  
Base Editing ◽  
Homology Directed Repair ◽  
Genome Wide ◽  
Culture Models ◽  
Liver Organoids ◽  
Target Effects

Abstract Prime editing is a recent genome editing technology using fusion proteins of Cas9-nickase and reverse transcriptase, that holds promise to correct the vast majority of genetic defects. Here, we develop prime editing for primary adult stem cells grown in organoid culture models. First, we generate precise in-frame deletions in the gene encoding β‐catenin (CTNNB1) that result in proliferation independent of Wnt-stimuli, mimicking a mechanism of the development of liver cancer. Moreover, prime editing functionally recovers disease-causing mutations in intestinal organoids from patients with DGAT1-deficiency and liver organoids from a patient with Wilson disease (ATP7B). Prime editing is as efficient in 3D grown organoids as in 2D grown cell lines and offers greater precision than Cas9-mediated homology directed repair (HDR). Base editing remains more reliable than prime editing but is restricted to a subgroup of pathogenic mutations. Whole-genome sequencing of four prime-edited clonal organoid lines reveals absence of genome-wide off-target effects underscoring therapeutic potential of this versatile and precise gene editing strategy.

Cytosine, but not adenine, base editors induce genome-wide off-target mutations in rice

Science ◽  
2019 ◽  
pp. eaaw7166 ◽  
Author(s):  
Shuai Jin ◽  
Yuan Zong ◽  
Qiang Gao ◽  
Zixu Zhu ◽  
Yanpeng Wang ◽  
...  
Keyword(s):  
High Fidelity ◽  
Single Nucleotide Variants ◽  
Disease Treatment ◽  
Single Nucleotide ◽  
Genetic Changes ◽  
Base Editing ◽  
Guide Rna ◽  
Genome Wide ◽  
Adenine Base

Cytosine and adenine base editors (CBEs and ABEs) are promising new tools for achieving the precise genetic changes required for disease treatment and trait improvement. However, genome-wide and unbiased analyses of their off-target effects in vivo are still lacking. Our whole genome sequencing (WGS) analysis of rice plants treated with BE3, high-fidelity BE3 (HF1-BE3), or ABE revealed that BE3 and HF1-BE3, but not ABE, induce substantial genome-wide off-target mutations, which are mostly the C→T type of single nucleotide variants (SNVs) and appear to be enriched in genic regions. Notably, treatment of rice with BE3 or HF1-BE3 in the absence of single-guide RNA also results in the rise of genome-wide SNVs. Thus, the base editing unit of BE3 or HF1-BE3 needs to be optimized in order to attain high fidelity.

scholarly journals No observable guide-RNA-independent off-target mutation induced by prime editor

2021 ◽  
Author(s):  
Runze Gao ◽  
Zhi-Can Fu ◽  
Xiangyang Li ◽  
Ying Wang ◽  
Jia Wei ◽  
...  
Keyword(s):  
Transcriptome Sequencing ◽  
High Specificity ◽  
Human Cells ◽  
Whole Genome ◽  
Guide Rna ◽  
Genome Wide ◽  
Target Sites ◽  
Whole Transcriptome Sequencing ◽  
Whole Transcriptome ◽  
Target Effects

Prime editor (PE) has been recently developed to induce efficient and precise on-target editing, whereas its guide RNA (gRNA)-independent off-target effects remain unknown. Here, we used whole-genome and whole-transcriptome sequencing to determine gRNA-independent off-target mutations in cells expanded from single colonies, in which PE generated precise editing at on-target sites. We found that PE triggered no observable gRNA-independent off-target mutation genome-wide or transcriptome-wide in transfected human cells, highlighting its high specificity.

Sign in / Sign up

Export Citation Format

Share Document