scholarly journals CRISPR-Cas9-mediated Large Cluster Deletion and Multiplex Genome Editing in Paenibacillus polymyxa

2021 ◽  
Author(s):  
Meliawati Meliawati ◽  
Christa Teckentrup ◽  
Jochen Schmid

Clustered regularly interspaced short palindromic repeats (CRISPR) system has rapidly advanced genetic engineering research. The system has been applied for different genetic engineering purposes in multiple organisms including the quite rarely explored Paenibacillus polymyxa. Only limited studies on CRISPR-based system have been described for this highly interesting and versatile bacterium. Here, we demonstrated the utilization of a Cas9-based system to realize 32.8 kb deletion of genomic region by using a single targeting sgRNA. Large cluster deletion was successfully performed with remarkable efficiency of 97 %. Furthermore, we also exploited the system for multiplexing by editing of two distantly located genes at once. We investigated double gene knockouts as well as simultaneous gene integrations and reached editing efficiencies of 78 % and 50 %, respectively. The findings reported in this study are anticipated to accelerate future research in P. polymyxa and related species.

2015 ◽  
Vol 1 (3) ◽  
pp. e1500248 ◽  
Author(s):  
Valmik K. Vyas ◽  
M. Inmaculada Barrasa ◽  
Gerald R. Fink

Candida albicansis a pathogenic yeast that causes mucosal and systematic infections with high mortality. The absence of facile molecular genetics has been a major impediment to analysis of pathogenesis. The lack of meiosis coupled with the absence of plasmids makes genetic engineering cumbersome, especially for essential functions and gene families. We describe aC. albicansCRISPR system that overcomes many of the obstacles to genetic engineering in this organism. The high frequency with which CRISPR-induced mutations can be directed to target genes enables easy isolation of homozygous gene knockouts, even without selection. Moreover, the system permits the creation of strains with mutations in multiple genes, gene families, and genes that encode essential functions. This CRISPR system is also effective in a fresh clinical isolate of undetermined ploidy. Our method transforms the ability to manipulate the genome ofCandidaand provides a new window into the biology of this pathogen.


2021 ◽  
Vol 22 (14) ◽  
pp. 7456
Author(s):  
Mousa A. Alghuthaymi ◽  
Aftab Ahmad ◽  
Zulqurnain Khan ◽  
Sultan Habibullah Khan ◽  
Farah K. Ahmed ◽  
...  

Rapid developments in the field of plant genome editing using clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas) systems necessitate more detailed consideration of the delivery of the CRISPR system into plants. Successful and safe editing of plant genomes is partly based on efficient delivery of the CRISPR system. Along with the use of plasmids and viral vectors as cargo material for genome editing, non-viral vectors have also been considered for delivery purposes. These non-viral vectors can be made of a variety of materials, including inorganic nanoparticles, carbon nanotubes, liposomes, and protein- and peptide-based nanoparticles, as well as nanoscale polymeric materials. They have a decreased immune response, an advantage over viral vectors, and offer additional flexibility in their design, allowing them to be functionalized and targeted to specific sites in a biological system with low cytotoxicity. This review is dedicated to describing the delivery methods of CRISPR system into plants with emphasis on the use of non-viral vectors.


mSphere ◽  
2017 ◽  
Vol 2 (2) ◽  
Author(s):  
Namkha Nguyen ◽  
Morgan M. F. Quail ◽  
Aaron D. Hernday

ABSTRACT Candida albicans is the most common fungal pathogen of humans. Historically, molecular genetic analysis of this important pathogen has been hampered by the lack of stable plasmids or meiotic cell division, limited selectable markers, and inefficient methods for generating gene knockouts. The recent development of clustered regularly interspaced short palindromic repeat(s) (CRISPR)-based tools for use with C. albicans has opened the door to more efficient genome editing; however, previously reported systems have specific limitations. We report the development of an optimized CRISPR-based genome editing system for use with C. albicans. Our system is highly efficient, does not require molecular cloning, does not leave permanent markers in the genome, and supports rapid, precise genome editing in C. albicans. We also demonstrate the utility of our system for generating two independent homozygous gene knockouts in a single transformation and present a method for generating homozygous wild-type gene addbacks at the native locus. Furthermore, each step of our protocol is compatible with high-throughput strain engineering approaches, thus opening the door to the generation of a complete C. albicans gene knockout library. IMPORTANCE Candida albicans is the major fungal pathogen of humans and is the subject of intense biomedical and discovery research. Until recently, the pace of research in this field has been hampered by the lack of efficient methods for genome editing. We report the development of a highly efficient and flexible genome editing system for use with C. albicans. This system improves upon previously published C. albicans CRISPR systems and enables rapid, precise genome editing without the use of permanent markers. This new tool kit promises to expedite the pace of research on this important fungal pathogen.


2021 ◽  
Author(s):  
Xuechun Feng ◽  
Lukas Kambic ◽  
Jared H.K. Nishimoto ◽  
Floyd A. Reed ◽  
Jai A. Denton ◽  
...  

Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 1862-1862
Author(s):  
Gregory J. Cost ◽  
Morayma Temoche-Diaz ◽  
Janet Mei ◽  
Cristina N. Butterfield ◽  
Christopher T. Brown ◽  
...  

Abstract RNA guided CRISPR genome editing systems can make specific changes to the genomes of mammalian cells and have the potential to treat a range of diseases including those that can be addressed by editing hepatocytes. Attempts to edit the liver in vivo have relied almost exclusively on the Cas9 nucleases derived from the bacteria S treptococcus pyogenes or Staphylococcus aureus to which humans are commonly exposed. Pre-existing immunity to both these proteins has been reported in humans which raises concerns about their in vivo application. In silico analysis of a large metagenomics database followed by testing in mammalian cells in culture identified MG29-1, a novel CRISPR system which is a member of the Type V family but exhibits only 41 % amino acid identity to Francisella tularensis Cas12a/cpf1. MG29-1 is a 1280 amino acid RNA programmable nuclease that utilizes a single guide RNA comprised of a 22 nucleotide (nt) constant region and a 20 to 25 nt spacer, recognizes the PAM KTTN (predicted frequency 1 in 16 bp) and generates staggered cuts. MG29-1 was derived from a sample taken from a hydrothermal vent and it is therefore unlikely that humans will have developed pre-existing immunity to this protein. A screen for sgRNA targeting serum albumin in the mouse liver cell line Hepa1-6 identified 6 guides that generated more than 80% INDELS. The MG29-1 system was optimized for in vivo delivery by screening chemical modifications to the guide that improve stability in mammalian cell lysates while retaining or improving editing activity. Two lead guide chemistries were evaluated in mice using MG29-1 mRNA and sgRNA packaged in lipid nanoparticles (LNP). Three days after a single IV administration on-target editing was evaluated in the liver by Sanger sequencing. The sgRNA that was the most stable in the in vitro assay generated INDELS that ranged from 20 to 25% while a sgRNA with lower in vitro stability failed to generate detectable INDELs. The short sgRNA and small protein size compared to spCas9 makes MG29-1 an attractive alternative to spCas9 for in vivo editing applications. Evaluation of the potential of MG29-1 to perform gene knockouts and gene additions via non-homologous end joining is ongoing. Disclosures No relevant conflicts of interest to declare.


Author(s):  
Thilani B. Jayakody ◽  
Felix Eugenio Enciso-Rodríguez ◽  
Jacob Jensen ◽  
David S. Douches ◽  
Satya Swathi Nadakuduti

Biomolecules ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 734 ◽  
Author(s):  
Yawei Zhao ◽  
Guoquan Li ◽  
Yunliang Chen ◽  
Yinhua Lu

The genome of Streptomyces encodes a high number of natural product (NP) biosynthetic gene clusters (BGCs). Most of these BGCs are not expressed or are poorly expressed (commonly called silent BGCs) under traditional laboratory experimental conditions. These NP BGCs represent an unexplored rich reservoir of natural compounds, which can be used to discover novel chemical compounds. To activate silent BGCs for NP discovery, two main strategies, including the induction of BGCs expression in native hosts and heterologous expression of BGCs in surrogate Streptomyces hosts, have been adopted, which normally requires genetic manipulation. So far, various genome editing technologies have been developed, which has markedly facilitated the activation of BGCs and NP overproduction in their native hosts, as well as in heterologous Streptomyces hosts. In this review, we summarize the challenges and recent advances in genome editing tools for Streptomyces genetic manipulation with a focus on editing tools based on clustered regularly interspaced short palindrome repeat (CRISPR)/CRISPR-associated protein (Cas) systems. Additionally, we discuss the future research focus, especially the development of endogenous CRISPR/Cas-based genome editing technologies in Streptomyces.


2020 ◽  
Vol 23 ◽  
Author(s):  
Laura Pasca ◽  
David Paniagua ◽  
Juan Ignacio Aragonés

Abstract Several instruments have been developed to measure the human beings-nature relationship, one of which is the Love and Care for Nature Scale. Three studies were conducted with the aim of analyzing to what extent the construct of love and care for nature, responds to two empirically different dimensions, as well as conducting a psychometric study of the scale. The analysis of construct components showed a large cluster formed by two others (connectedness and well-being), considered “love for nature”, and one two-items cluster referring to “care” (Study 1, n = 51). Considering the “love” items, it was found that ten of the items present adequate psychometric properties (Study 2, n = 1071), and adequate levels of reliability and validity (Study 3, n = 151). Consequently, an appropriate measure of love of nature is established, while an interesting future research line would be to separately study the scale’s two components.


2019 ◽  
Vol 47 (14) ◽  
pp. 7402-7417 ◽  
Author(s):  
Dominic D G Owens ◽  
Adam Caulder ◽  
Vincent Frontera ◽  
Joe R Harman ◽  
Alasdair J Allan ◽  
...  

Abstract The CRISPR system is widely used in genome editing for biomedical research. Here, using either dual paired Cas9D10A nickases or paired Cas9 nuclease we characterize unintended larger deletions at on-target sites that frequently evade common genotyping practices. We found that unintended larger deletions are prevalent at multiple distinct loci on different chromosomes, in cultured cells and mouse embryos alike. We observed a high frequency of microhomologies at larger deletion breakpoint junctions, suggesting the involvement of microhomology-mediated end joining in their generation. In populations of edited cells, the distribution of larger deletion sizes is dependent on proximity to sgRNAs and cannot be predicted by microhomology sequences alone.


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