High-efficiency multiplex genome editing of Streptomyces species using an engineered CRISPR/Cas system.
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ABSTRACT:
SUBMITTER: Cobb RE
PROVIDER: S-EPMC4459934 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Streptomyces strains produce a great number of valuable natural products. With the development of genome sequencing, a vast number of biosynthetic gene clusters with high potential for use in the discovery of valuable clinical drugs have been revealed. Therefore, emerging needs for tools to manipulate these biosynthetic pathways are presented. Although the clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR/Cas 9) system has exhibited great capabilities for gene editing in multiple Streptomyces strains, it has failed to work in some newly discovered strains and some important industrial strains. Additionally, the protospacer adjacent motif (PAM) recognition scope of this system sometimes limits its applications for generating precise site mutations and insertions. Here, we developed three efficient CRISPR-FnCas12a systems for multiplex genome editing in several Streptomyces strains. Each system exhibited advantages for different applications. The CRISPR-FnCas12a1 system was efficiently applied in the industrial strain Streptomyces hygroscopicus, in which SpCas9 does not work well. The CRISPR-FnCas12a2 system was used to delete large fragments ranging from 21.4 to 128 kb. Additionally, the CRISPR-FnCas12a3 system employing the engineered FnCas12a mutant EP16, which recognizes a broad spectrum of PAM sequences, was used to precisely perform site mutations and insertions. The CRISPR-FnCas12a3 system addressed the limitation of TTN PAM recognition in Streptomyces strains with high GC contents. In summary, all the CRISPR-FnCas12a systems developed in this study are powerful tools for precise and multiplex genome editing in Streptomyces strains.
| S-EPMC7338789 | biostudies-literature
Project description:Compact and versatile CRISPR-Cas systems will enable genome engineering applications through high-efficiency delivery in a wide variety of contexts. Here we create an efficient miniature Cas system (CasMINI) engineered from the type V-F Cas12f (Cas14) system by guide RNA and protein engineering, which is less than half the size of currently used CRISPR systems (Cas9 or Cas12a). We demonstrate that CasMINI can drive high levels of gene activation (up to thousands-fold increases), while the natural Cas12f system fails to function in mammalian cells. We show that the CasMINI system has comparable activities to Cas12a for gene activation, is highly specific, and allows for robust base editing and gene editing. We expect that CasMINI can be broadly useful for cell engineering and gene therapy applications ex vivo and in vivo.
2021-09-10 | GSE180773 | GEO
Project description:Studies of molecular mechanisms and related gene functions have long been restricted by limited genome editing technologies in malaria parasites. Recently, a simple and effective genome editing technology, the CRISPR/Cas (clustered regularly interspaced short palindromic repeats/CRISPR-associated) system, has greatly facilitated these studies in many organisms, including malaria parasites. However, due to the special genome feature of malaria parasites, the manipulation and gene editing efficacy of the CRISPR/Cas system in this pathogen need to be improved, particularly in the human malaria parasite, Plasmodium falciparum. Herein, based on the CRISPR/Cas9 system, we developed an integrating strategy to generate a Cas9i system, which significantly shortened the time for generation of transgenic strains in P. falciparum. Moreover, with this Cas9i system, we have successfully achieved multiplexed genome editing (mutating or tagging) by a single-round transfection in P. falciparum. In addition, we for the first time adapted AsCpf1 (Acidaminococcus sp. Cpf1), an alternative to Cas9, into P. falciparum parasites and examined it for gene editing. These optimizations of the CRISPR/Cas system will further facilitate the mechanistic research of malaria parasites and contribute to eliminating malaria in the future.
| S-EPMC7819880 | biostudies-literature
Project description:Streptomyces has a strong capability for producing a large number of bioactive natural products and remains invaluable as a source for the discovery of novel drug leads. Although the Streptococcus pyogenes CRISPR-Cas9-assisted genome editing tool has been developed for rapid genetic engineering in Streptomyces, it has a number of limitations, including the toxicity of SpCas9 expression in some important industrial Streptomyces strains and the need for complex expression constructs when targeting multiple genomic loci. To address these problems, in this study, we developed a high-efficiency CRISPR-Cpf1 system (from Francisella novicida) for multiplex genome editing and transcriptional repression in Streptomyces Using an all-in-one editing plasmid with homology-directed repair (HDR), our CRISPR-Cpf1 system precisely deletes single or double genes at efficiencies of 75 to 95% in Streptomyces coelicolor When no templates for HDR are present, random-sized DNA deletions are achieved by FnCpf1-induced double-strand break (DSB) repair by a reconstituted nonhomologous end joining (NHEJ) pathway. Furthermore, a DNase-deactivated Cpf1 (ddCpf1)-based integrative CRISPRi system is developed for robust, multiplex gene repression using a single customized crRNA array. Finally, we demonstrate that FnCpf1 and SpCas9 exhibit different suitability in tested industrial Streptomyces species and show that FnCpf1 can efficiently promote HDR-mediated gene deletion in the 5-oxomilbemycin-producing strain Streptomyces hygroscopicus SIPI-KF, in which SpCas9 does not work well. Collectively, FnCpf1 is a powerful and indispensable addition to the Streptomyces CRISPR toolbox.IMPORTANCE Rapid, efficient genetic engineering of Streptomyces strains is critical for genome mining of novel natural products (NPs) as well as strain improvement. Here, a novel and high-efficiency Streptomyces genome editing tool is established based on the FnCRISPR-Cpf1 system, which is an attractive and powerful alternative to the S. pyogenes CRISPR-Cas9 system due to its unique features. When combined with HDR or NHEJ, FnCpf1 enables the creation of gene(s) deletion with high efficiency. Furthermore, a ddCpf1-based integrative CRISPRi platform is established for simple, multiplex transcriptional repression. Of importance, FnCpf1-based genome editing proves to be a highly efficient tool for genetic modification of some important industrial Streptomyces strains (e.g., S. hygroscopicus SIPI-KF) that cannot utilize the SpCRISPR-Cas9 system. We expect the CRISPR-Cpf1-assisted genome editing tool to accelerate discovery and development of pharmaceutically active NPs in Streptomyces as well as other actinomycetes.
| S-EPMC6121969 | biostudies-literature
Project description:Genome editing by sgRNA a component of CRISPR/Cas system emerged as a preferred technology for genome editing in recent years. However, activity and stability of sgRNA in genome targeting is greatly influenced by its sequence features. In this endeavor, a few prediction tools have been developed to design effective sgRNAs but these methods have their own limitations. Therefore, we have developed "ge-CRISPR" using high throughput data for the prediction and analysis of sgRNAs genome editing efficiency. Predictive models were employed using SVM for developing pipeline-1 (classification) and pipeline-2 (regression) using 2090 and 4139 experimentally verified sgRNAs respectively from Homo sapiens, Mus musculus, Danio rerio and Xenopus tropicalis. During 10-fold cross validation we have achieved accuracy and Matthew's correlation coefficient of 87.70% and 0.75 for pipeline-1 on training dataset (T(1840)) while it performed equally well on independent dataset (V(250)). In pipeline-2 we attained Pearson correlation coefficient of 0.68 and 0.69 using best models on training (T(3169)) and independent dataset (V(520)) correspondingly. ge-CRISPR (http://bioinfo.imtech.res.in/manojk/gecrispr/) for a given genomic region will identify potent sgRNAs, their qualitative as well as quantitative efficiencies along with potential off-targets. It will be useful to scientific community engaged in CRISPR research and therapeutics development.
| S-EPMC5007494 | biostudies-literature
Project description:In bacteria, foreign nucleic acids are silenced by clustered, regularly interspaced, short palindromic repeats (CRISPR)--CRISPR-associated (Cas) systems. Bacterial type II CRISPR systems have been adapted to create guide RNAs that direct site-specific DNA cleavage by the Cas9 endonuclease in cultured cells. Here we show that the CRISPR-Cas system functions in vivo to induce targeted genetic modifications in zebrafish embryos with efficiencies similar to those obtained using zinc finger nucleases and transcription activator-like effector nucleases.
| S-EPMC3686313 | biostudies-literature
Project description:We have previously reported a simple and customizable CRISPR (clustered regularly interspaced short palindromic repeats) RNA-guided Cas9 nuclease (RGN) system that can be used to efficiently and robustly introduce somatic indel mutations in endogenous zebrafish genes. Here we demonstrate that RGN-induced mutations are heritable, with efficiencies of germline transmission reaching as high as 100%. In addition, we extend the power of the RGN system by showing that these nucleases can be used with single-stranded oligodeoxynucleotides (ssODNs) to create precise intended sequence modifications, including single nucleotide substitutions. Finally, we describe and validate simple strategies that improve the targeting range of RGNs from 1 in every 128 basepairs (bps) of random DNA sequence to 1 in every 8 bps. Together, these advances expand the utility of the CRISPR-Cas system in the zebrafish beyond somatic indel formation to heritable and precise genome modifications.
| S-EPMC3706373 | biostudies-literature
Project description:CRISPR-Cas is an efficient method for genome editing in organisms from bacteria to human cells. We describe a transgene-free method for CRISPR-Cas-mediated cleavage in nematodes, enabling RNA-homology-targeted deletions that cause loss of gene function; analysis of whole-genome sequencing indicates that the nuclease activity is highly specific.
| S-EPMC3813845 | biostudies-other
Project description:Functional elucidation of causal genetic variants and elements requires precise genome editing technologies. The type II prokaryotic CRISPR (clustered regularly interspaced short palindromic repeats)/Cas adaptive immune system has been shown to facilitate RNA-guided site-specific DNA cleavage. We engineered two different type II CRISPR/Cas systems and demonstrate that Cas9 nucleases can be directed by short RNAs to induce precise cleavage at endogenous genomic loci in human and mouse cells. Cas9 can also be converted into a nicking enzyme to facilitate homology-directed repair with minimal mutagenic activity. Lastly, multiple guide sequences can be encoded into a single CRISPR array to enable simultaneous editing of several sites within the mammalian genome, demonstrating easy programmability and wide applicability of the RNA-guided nuclease technology.
| S-EPMC3795411 | biostudies-literature
Project description:A simple and robust method for targeted mutagenesis in zebrafish has long been sought. Previous methods generate monoallelic mutations in the germ line of F0 animals, usually delaying homozygosity for the mutation to the F2 generation. Generation of robust biallelic mutations in the F0 would allow for phenotypic analysis directly in injected animals. Recently the type II prokaryotic clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated proteins (Cas) system has been adapted to serve as a targeted genome mutagenesis tool. Here we report an improved CRISPR/Cas system in zebrafish with custom guide RNAs and a zebrafish codon-optimized Cas9 protein that efficiently targeted a reporter transgene Tg(-5.1mnx1:egfp) and four endogenous loci (tyr, golden, mitfa, and ddx19). Mutagenesis rates reached 75-99%, indicating that most cells contained biallelic mutations. Recessive null-like phenotypes were observed in four of the five targeting cases, supporting high rates of biallelic gene disruption. We also observed efficient germ-line transmission of the Cas9-induced mutations. Finally, five genomic loci can be targeted simultaneously, resulting in multiple loss-of-function phenotypes in the same injected fish. This CRISPR/Cas9 system represents a highly effective and scalable gene knockout method in zebrafish and has the potential for applications in other model organisms.
| S-EPMC3752207 | biostudies-literature