scholarly journals Enhanced guide-RNA design and targeting analysis for precise CRISPR genome editing of single and consortia of industrially relevant and non-model organisms

2017 ◽  
Vol 34 (1) ◽  
pp. 16-23 ◽  
Author(s):  
Brian J Mendoza ◽  
Cong T Trinh
2017 ◽  
Author(s):  
Brian J. Mendoza ◽  
Cong T. Trinh

AbstractMotivationGenetic diversity of non-model organisms offers a repertoire of unique phenotypic features for exploration and cultivation for synthetic biology and metabolic engineering applications. To realize this enormous potential, it is critical to have an efficient genome editing tool for rapid strain engineering of these organisms to perform novel programmed functions.ResultsTo accommodate the use of CRISPR/Cas systems for genome editing across organisms, we have developed a novel method, named CASPER (CRISPR Associated Software for Pathway Engineering and Research), for identifying on- and off-targets with enhanced predictability coupled with an analysis of non-unique (repeated) targets to assist in editing any organism with various endonucleases. Utilizing CASPER, we demonstrated a modest 2.4% and significant 30.2% improvement (F-test, p<0.05) over the conventional methods for predicting on- and off-target activities, respectively. Further we used CASPER to develop novel applications in genome editing: multitargeting analysis (i.e. simultaneous multiple-site modification on a target genome with a sole guide-RNA (gRNA) requirement) and multispecies population analysis (i.e. gRNA design for genome editing across a consortium of organisms). Our analysis on a selection of industrially relevant organisms revealed a number of non-unique target sites associated with genes and transposable elements that can be used as potential sites for multitargeting. The analysis also identified shared and unshared targets that enable genome editing of single or multiple genomes in a consortium of interest. We envision CASPER as a useful platform to enhance the precise CRISPR genome editing for metabolic engineering and synthetic biology applications.


2018 ◽  
Vol 479 (1) ◽  
pp. 90-94 ◽  
Author(s):  
A. V. Khromov ◽  
V. A. Gushchin ◽  
V. I. Timerbaev ◽  
N. O. Kalinina ◽  
M. E. Taliansky ◽  
...  

2019 ◽  
Author(s):  
Mahmudur Rahman Hera ◽  
Amatur Rahman ◽  
Atif Rahman

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.


2019 ◽  
Author(s):  
Chiao-Lin Chen ◽  
Jonathan Rodiger ◽  
Verena Chung ◽  
Raghuvir Viswanatha ◽  
Stephanie E. Mohr ◽  
...  

ABSTRACTCRISPR-Cas9 is a powerful genome editing technology in which a single guide RNA (sgRNA) confers target site specificity to achieve Cas9-mediated genome editing. Numerous sgRNA design tools have been developed based on reference genomes for humans and model organisms. However, existing resources are not optimal as genetic mutations or single nucleotide polymorphisms (SNPs) within the targeting region affect the efficiency of CRISPR-based approaches by interfering with guide-target complementarity. To facilitate identification of sgRNAs (1) in non-reference genomes, (2) across varying genetic backgrounds, or (3) for specific targeting of SNP-containing alleles, for example, disease relevant mutations, we developed a web tool, SNP-CRISPR (https://www.flyrnai.org/tools/snp_crispr/). SNP-CRISPR can be used to design sgRNAs based on public variant data sets or user-identified variants. In addition, the tool computes efficiency and specificity scores for sgRNA designs targeting both the variant and the reference. Moreover, SNP-CRISPR provides the option to upload multiple SNPs and target single or multiple nearby base changes simultaneously with a single sgRNA design. Given these capabilities, SNP-CRISPR has a wide range of potential research applications in model systems and for design of sgRNAs for disease-associated variant correction.


2020 ◽  
Author(s):  
Xinyi Guo ◽  
Hans-Hermann Wessels ◽  
Alejandro Méndez-Mancilla ◽  
Daniel Haro ◽  
Neville E. Sanjana

AbstractCRISPR-Cas13 mediates robust transcript knockdown in human cells through direct RNA targeting. Compared to DNA-targeting CRISPR enzymes like Cas9, RNA targeting by Cas13 is transcript- and strand-specific: It can distinguish and specifically knock-down processed transcripts, alternatively spliced isoforms and overlapping genes, all of which frequently serve different functions. Previously, we identified optimal design rules for RfxCas13d guide RNAs (gRNAs), and developed a computational model to predict gRNA efficacy for all human protein-coding genes. However, there is a growing interest to target other types of transcripts, such as noncoding RNAs (ncRNAs) or viral RNAs, and to target transcripts in other commonly-used organisms. Here, we predicted relative Cas13-driven knock-down for gRNAs targeting messenger RNAs and ncRNAs in six model organisms (human, mouse, zebrafish, fly, nematode and flowering plants) and four abundant RNA virus families (SARS-CoV-2, HIV-1, H1N1 influenza and MERS). To allow for more flexible gRNA efficacy prediction, we also developed a web-based application to predict optimal gRNAs for any RNA target entered by the user. Given the lack of Cas13 guide design tools, we anticipate this resource will facilitate CRISPR-Cas13 RNA targeting in common model organisms, emerging viral threats to human health, and novel RNA targets.


2019 ◽  
Vol 10 (2) ◽  
pp. 489-494 ◽  
Author(s):  
Chiao-Lin Chen ◽  
Jonathan Rodiger ◽  
Verena Chung ◽  
Raghuvir Viswanatha ◽  
Stephanie E. Mohr ◽  
...  

CRISPR-Cas9 is a powerful genome editing technology in which a single guide RNA (sgRNA) confers target site specificity to achieve Cas9-mediated genome editing. Numerous sgRNA design tools have been developed based on reference genomes for humans and model organisms. However, existing resources are not optimal as genetic mutations or single nucleotide polymorphisms (SNPs) within the targeting region affect the efficiency of CRISPR-based approaches by interfering with guide-target complementarity. To facilitate identification of sgRNAs (1) in non-reference genomes, (2) across varying genetic backgrounds, or (3) for specific targeting of SNP-containing alleles, for example, disease relevant mutations, we developed a web tool, SNP-CRISPR (https://www.flyrnai.org/tools/snp_crispr/). SNP-CRISPR can be used to design sgRNAs based on public variant data sets or user-identified variants. In addition, the tool computes efficiency and specificity scores for sgRNA designs targeting both the variant and the reference. Moreover, SNP-CRISPR provides the option to upload multiple SNPs and target single or multiple nearby base changes simultaneously with a single sgRNA design. Given these capabilities, SNP-CRISPR has a wide range of potential research applications in model systems and for design of sgRNAs for disease-associated variant correction.


Author(s):  
Kaiyuan Chen ◽  
◽  
Hao Liu ◽  
Kabin Xie ◽  
Muhammad Tahir ul Qamar ◽  
...  

This chapter discusses the general rules for selecting target sites for genome editing using the CRISPR-Cas technology and summarizes the bioinformatic tools that can be used to design sgRNA sequences.


2019 ◽  
Author(s):  
Dylan Beeber ◽  
Frédéric JJ Chain

AbstractThe success of CRISPR/Cas9 gene editing applications relies on the efficiency of the single guide RNA (sgRNA) used in conjunction with the Cas9 protein. Current sgRNA design software vary in the details they provide on sgRNA sequence efficiency and are almost exclusively restricted to model organisms. The crispRdesignR package aims to address these limitations by providing comprehensive sequence features of the generated sgRNAs in a single program, which allows users to predict sgRNA efficiency and design sgRNA sequences for systems that currently do not have optimized efficiency scoring methods. crispRdesignR reports extensive information on all designed sgRNA sequences with robust off-target calling and annotation and can be run in a user-friendly graphical interface. The crispRdesignR package is implemented in R and has fully editable code for specialized purposes including sgRNA design in user-provided genomes. The package is platform independent and extendable, with its source code and documentation freely available at https://github.com/dylanbeeber/crispRdesignR.


Genetics ◽  
2015 ◽  
Vol 199 (4) ◽  
pp. 959-971 ◽  
Author(s):  
Behnom Farboud ◽  
Barbara J. Meyer
Keyword(s):  

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