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Murali SK, Mansell TJ. Next generation probiotics: Engineering live biotherapeutics. Biotechnol Adv 2024; 72:108336. [PMID: 38432422 DOI: 10.1016/j.biotechadv.2024.108336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Revised: 02/10/2024] [Accepted: 02/25/2024] [Indexed: 03/05/2024]
Abstract
The population dynamics of the human microbiome have been associated with inflammatory bowel disease, cancer, obesity, autoimmune diseases, and many other human disease states. An emerging paradigm in treatment is the administration of live engineered organisms, also called next-generation probiotics. However, the efficacy of these microbial therapies can be limited by the organism's overall performance in the harsh and nutrient-limited environment of the gut. In this review, we summarize the current state of the art use of bacterial and yeast strains as probiotics, highlight the recent development of genetic tools for engineering new therapeutic functions in these organisms, and report on the latest therapeutic applications of engineered probiotics, including recent clinical trials. We also discuss the supplementation of prebiotics as a method of manipulating the microbiome and improving the overall performance of engineered live biotherapeutics.
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Affiliation(s)
- Sanjeeva Kumar Murali
- Department of Chemical and Biological Engineering, Iowa State University, Ames, IA 50011, USA.
| | - Thomas J Mansell
- Department of Chemical and Biological Engineering, Iowa State University, Ames, IA 50011, USA; Interdepartmental Microbiology Graduate Program, Iowa State University, Ames, IA 50011, USA.
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2
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Szekely O, Rangadurai AK, Gu S, Manghrani A, Guseva S, Al-Hashimi HM. NMR measurements of transient low-populated tautomeric and anionic Watson-Crick-like G·T/U in RNA:DNA hybrids: implications for the fidelity of transcription and CRISPR/Cas9 gene editing. Nucleic Acids Res 2024; 52:2672-2685. [PMID: 38281263 PMCID: PMC10954477 DOI: 10.1093/nar/gkae027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 01/02/2024] [Accepted: 01/17/2024] [Indexed: 01/30/2024] Open
Abstract
Many biochemical processes use the Watson-Crick geometry to distinguish correct from incorrect base pairing. However, on rare occasions, mismatches such as G·T/U can transiently adopt Watson-Crick-like conformations through tautomerization or ionization of the bases, giving rise to replicative and translational errors. The propensities to form Watson-Crick-like mismatches in RNA:DNA hybrids remain unknown, making it unclear whether they can also contribute to errors during processes such as transcription and CRISPR/Cas editing. Here, using NMR R1ρ experiments, we show that dG·rU and dT·rG mismatches in two RNA:DNA hybrids transiently form tautomeric (Genol·T/U $ \mathbin{\lower.3ex\hbox{$\buildrel\textstyle\rightarrow\over {\smash{\leftarrow}\vphantom{_{\vbox to.5ex{\vss}}}}$}}$ G·Tenol/Uenol) and anionic (G·T-/U-) Watson-Crick-like conformations. The tautomerization dynamics were like those measured in A-RNA and B-DNA duplexes. However, anionic dG·rU- formed with a ten-fold higher propensity relative to dT-·rG and dG·dT- and this could be attributed to the lower pKa (ΔpKa ∼0.4-0.9) of U versus T. Our findings suggest plausible roles for Watson-Crick-like G·T/U mismatches in transcriptional errors and CRISPR/Cas9 off-target gene editing, uncover a crucial difference between the chemical dynamics of G·U versus G·T, and indicate that anionic Watson-Crick-like G·U- could play a significant role evading Watson-Crick fidelity checkpoints in RNA:DNA hybrids and RNA duplexes.
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Affiliation(s)
- Or Szekely
- Department of Biology, Duke University, Durham, NC 27710, USA
- Howard Hughes Medical Institute, Duke University, Durham, NC 27710, USA
| | | | - Stephanie Gu
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
- Department of Biochemistry and Molecular Biophysics, Columbia University, NY, NY 10032, USA
| | - Akanksha Manghrani
- Department of Biochemistry, Duke University School of Medicine, Durham, NC 27710, USA
- Department of Biochemistry and Molecular Biophysics, Columbia University, NY, NY 10032, USA
| | - Serafima Guseva
- Department of Biochemistry and Molecular Biophysics, Columbia University, NY, NY 10032, USA
| | - Hashim M Al-Hashimi
- Department of Biochemistry and Molecular Biophysics, Columbia University, NY, NY 10032, USA
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3
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Gupta R, Rohde KH. Implementation of a mycobacterial CRISPRi platform in Mycobacterium abscessus and demonstration of the essentiality of ftsZ Mab. Tuberculosis (Edinb) 2023; 138:102292. [PMID: 36495774 DOI: 10.1016/j.tube.2022.102292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 11/22/2022] [Accepted: 11/27/2022] [Indexed: 12/04/2022]
Abstract
Mycobacterium abscessus (Mab) is a highly drug-resistant non-tuberculous mycobacterial species that causes debilitating TB-like pulmonary infections. The lack of genetic tools has hampered characterization of its extensive repertoire of virulence factors, antimicrobial resistance mechanisms, and drug targets. In this study, we evaluated the performance of a mycobacterial single plasmid CRISPRi-dCas9 system optimized for M. tuberculosis and M. smegmatis for inducible gene silencing in Mab. The efficacy of CRISPRi-mediated repression of two antibiotic resistance genes (blaMab, whiB7Mab) and two putative essential genes (ftsZMab,topAMab) was determined by measuring mRNA transcript levels and phenotypic outcomes. While our results support the utility of this mycobacterial CRISPRi dCas9Sth1 single-plasmid platform for inducible silencing of specific target genes in Mab, they also highlighted several caveats and nuances that may warrant species-specific optimization for Mab. We observed overall lower levels of gene repression in Mab including variable silencing of different target genes despite use of PAMs of similar predicted strength. In addition, leaky gene repression in the absence of inducer was noted for some genes but not others. Nonetheless, using CRISPRi we demonstrated the silencing of multiple target genes and validated ftsZMab as an essential gene and promising drug target for the first time.
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Affiliation(s)
- Rashmi Gupta
- Division of Immunity and Pathogenesis, College of Medicine, Burnett School of Biomedical Sciences, University of Central Florida, 6900 Lake Nona Blvd, FL, 32827, USA.
| | - Kyle H Rohde
- Division of Immunity and Pathogenesis, College of Medicine, Burnett School of Biomedical Sciences, University of Central Florida, 6900 Lake Nona Blvd, FL, 32827, USA.
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Lam TJ, Mortensen K, Ye Y. Diversity and dynamics of the CRISPR-Cas systems associated with Bacteroides fragilis in human population. BMC Genomics 2022; 23:573. [PMID: 35953824 PMCID: PMC9367070 DOI: 10.1186/s12864-022-08770-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 07/15/2022] [Indexed: 11/22/2022] Open
Abstract
Background CRISPR-Cas (clustered regularly interspaced short palindromic repeats—CRISPR-associated proteins) systems are adaptive immune systems commonly found in prokaryotes that provide sequence-specific defense against invading mobile genetic elements (MGEs). The memory of these immunological encounters are stored in CRISPR arrays, where spacer sequences record the identity and history of past invaders. Analyzing such CRISPR arrays provide insights into the dynamics of CRISPR-Cas systems and the adaptation of their host bacteria to rapidly changing environments such as the human gut. Results In this study, we utilized 601 publicly available Bacteroides fragilis genome isolates from 12 healthy individuals, 6 of which include longitudinal observations, and 222 available B. fragilis reference genomes to update the understanding of B. fragilis CRISPR-Cas dynamics and their differential activities. Analysis of longitudinal genomic data showed that some CRISPR array structures remained relatively stable over time whereas others involved radical spacer acquisition during some periods, and diverse CRISPR arrays (associated with multiple isolates) co-existed in the same individuals with some persisted over time. Furthermore, features of CRISPR adaptation, evolution, and microdynamics were highlighted through an analysis of host-MGE network, such as modules of multiple MGEs and hosts, reflecting complex interactions between B. fragilis and its invaders mediated through the CRISPR-Cas systems. Conclusions We made available of all annotated CRISPR-Cas systems and their target MGEs, and their interaction network as a web resource at https://omics.informatics.indiana.edu/CRISPRone/Bfragilis. We anticipate it will become an important resource for studying of B. fragilis, its CRISPR-Cas systems, and its interaction with mobile genetic elements providing insights into evolutionary dynamics that may shape the species virulence and lead to its pathogenicity. Supplementary Information The online version contains supplementary material available at (10.1186/s12864-022-08770-8).
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Affiliation(s)
- Tony J Lam
- School of Informatics, Computing and Engineering, Indiana University, Bloomington, IN, USA
| | - Kate Mortensen
- School of Informatics, Computing and Engineering, Indiana University, Bloomington, IN, USA
| | - Yuzhen Ye
- School of Informatics, Computing and Engineering, Indiana University, Bloomington, IN, USA.
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Li Y, Mikkelsen K, Lluch I Grané O, Wang Z, Tang Y, Jiao X, Ingmer H, Høyland-Kroghsbo NM, Li Q. Functional Characterization of Type III-A CRISPR-Cas in a Clinical Human Methicillin-R Staphylococcus aureus Strain. CRISPR J 2021; 4:686-698. [PMID: 34558981 DOI: 10.1089/crispr.2021.0046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
CRISPR with its cas genes is an adaptive immune system that protects prokaryotes against foreign genetic elements. The type III-A CRISPR-Cas system is rarely found in Staphylococcus aureus, and little is known about its function in S. aureus. Here, we describe the genome characteristics of the clinical methicillin-resistant S. aureus (MRSA) strain TZ0912, carrying a type III-A CRISPR-Cas system. Phylogenetic analysis of 35 reported CRISPR-Cas-positive S. aureus strains revealed that the CRISPR-Cas system is prevalent in CC8 clones (10/35) and is located in the staphylococcal cassette chromosome mec (SCCmec) V, which confers methicillin resistance. Plasmid transformation and phage infection assays reveal that the type III-A CRISPR-Cas system protects TZ0912 against foreign DNA with sequence homology to the spacers located in the CRISPR array. We observed that the CRISPR-Cas immune system could effectively protect MRSA against phage attacks in both liquid culture and solid medium. In accordance with previous reports, using RNA-seq analysis and plasmid transformation assays, we find that the crRNAs close to the leading sequence of the CRISPR array are more highly expressed and are more effective at directing plasmid elimination compared to the distant spacers. This study established a model for evaluating the efficiency of naive CRISPR-Cas system in MRSA against phage, which could contribute to future research on the function of CRISPR-Cas in clinical MRSA isolates and improve phage therapy against MRSA infections.
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Affiliation(s)
- Yang Li
- Jiangsu Key Lab of Zoonosis/Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, P.R. China; University of Copenhagen, Copenhagen, Denmark.,Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agri-food Safety and Quality, Ministry of Agriculture of China, Yangzhou University, P.R. China; University of Copenhagen, Copenhagen, Denmark
| | - Kasper Mikkelsen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark; University of Copenhagen, Copenhagen, Denmark
| | - Oleguer Lluch I Grané
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark; University of Copenhagen, Copenhagen, Denmark
| | - Zhenyu Wang
- Jiangsu Key Lab of Zoonosis/Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, P.R. China; University of Copenhagen, Copenhagen, Denmark.,Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agri-food Safety and Quality, Ministry of Agriculture of China, Yangzhou University, P.R. China; University of Copenhagen, Copenhagen, Denmark
| | - Yuanyue Tang
- Jiangsu Key Lab of Zoonosis/Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, P.R. China; University of Copenhagen, Copenhagen, Denmark.,Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agri-food Safety and Quality, Ministry of Agriculture of China, Yangzhou University, P.R. China; University of Copenhagen, Copenhagen, Denmark.,Joint International Research Laboratory of Agriculture and Agri-Product Safety, Yangzhou University, P.R. China; and University of Copenhagen, Copenhagen, Denmark
| | - Xinan Jiao
- Jiangsu Key Lab of Zoonosis/Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, P.R. China; University of Copenhagen, Copenhagen, Denmark.,Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agri-food Safety and Quality, Ministry of Agriculture of China, Yangzhou University, P.R. China; University of Copenhagen, Copenhagen, Denmark.,Joint International Research Laboratory of Agriculture and Agri-Product Safety, Yangzhou University, P.R. China; and University of Copenhagen, Copenhagen, Denmark
| | - Hanne Ingmer
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark; University of Copenhagen, Copenhagen, Denmark
| | | | - Qiuchun Li
- Jiangsu Key Lab of Zoonosis/Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University, P.R. China; University of Copenhagen, Copenhagen, Denmark.,Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agri-food Safety and Quality, Ministry of Agriculture of China, Yangzhou University, P.R. China; University of Copenhagen, Copenhagen, Denmark.,Joint International Research Laboratory of Agriculture and Agri-Product Safety, Yangzhou University, P.R. China; and University of Copenhagen, Copenhagen, Denmark
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Bratovič M, Fonfara I, Chylinski K, Gálvez EJC, Sullivan TJ, Boerno S, Timmermann B, Boettcher M, Charpentier E. Bridge helix arginines play a critical role in Cas9 sensitivity to mismatches. Nat Chem Biol 2020; 16:587-595. [PMID: 32123387 DOI: 10.1038/s41589-020-0490-4] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 01/30/2020] [Indexed: 12/31/2022]
Abstract
The RNA-programmable DNA-endonuclease Cas9 is widely used for genome engineering, where a high degree of specificity is required. To investigate which features of Cas9 determine the sensitivity to mismatches along the target DNA, we performed in vitro biochemical assays and bacterial survival assays in Escherichia coli. We demonstrate that arginines in the Cas9 bridge helix influence guide RNA, and target DNA binding and cleavage. They cluster in two groups that either increase or decrease the Cas9 sensitivity to mismatches. We show that the bridge helix is essential for R-loop formation and that R63 and R66 reduce Cas9 specificity by stabilizing the R-loop in the presence of mismatches. Additionally, we identify Q768 that reduces sensitivity of Cas9 to protospacer adjacent motif-distal mismatches. The Cas9_R63A/Q768A variant showed increased specificity in human cells. Our results provide a firm basis for function- and structure-guided mutagenesis to increase Cas9 specificity for genome engineering.
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Affiliation(s)
- Majda Bratovič
- Max Planck Unit for the Science of Pathogens, Berlin, Germany.,Department of Regulation in Infection Biology, Max Planck Institute for Infection Biology, Berlin, Germany.,Institute for Biology, Humboldt University, Berlin, Germany.,Department of Regulation in Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Ines Fonfara
- Department of Regulation in Infection Biology, Max Planck Institute for Infection Biology, Berlin, Germany.,Department of Regulation in Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany.,The Laboratory for Molecular Infection Medicine Sweden, Umeå Centre for Microbial Research, Department of Molecular Biology, Umeå University, Umeå, Sweden
| | - Krzysztof Chylinski
- The Laboratory for Molecular Infection Medicine Sweden, Umeå Centre for Microbial Research, Department of Molecular Biology, Umeå University, Umeå, Sweden.,Max F. Perutz Laboratories, University of Vienna, Vienna, Austria.,Protein Technologies Facility, The Vienna Biocenter Core Facilities GmbH (VBCF), Vienna, Austria
| | - Eric J C Gálvez
- Max Planck Unit for the Science of Pathogens, Berlin, Germany.,Department of Regulation in Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | | | - Stefan Boerno
- Sequencing Core Facility, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Bernd Timmermann
- Sequencing Core Facility, Max Planck Institute for Molecular Genetics, Berlin, Germany
| | - Michael Boettcher
- Max Planck Unit for the Science of Pathogens, Berlin, Germany.,Medical Faculty, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Emmanuelle Charpentier
- Max Planck Unit for the Science of Pathogens, Berlin, Germany. .,Department of Regulation in Infection Biology, Max Planck Institute for Infection Biology, Berlin, Germany. .,Institute for Biology, Humboldt University, Berlin, Germany. .,Department of Regulation in Infection Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany. .,The Laboratory for Molecular Infection Medicine Sweden, Umeå Centre for Microbial Research, Department of Molecular Biology, Umeå University, Umeå, Sweden.
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Almendros C, Nobrega FL, McKenzie RE, Brouns SJJ. Cas4-Cas1 fusions drive efficient PAM selection and control CRISPR adaptation. Nucleic Acids Res 2019; 47:5223-5230. [PMID: 30937444 PMCID: PMC6547450 DOI: 10.1093/nar/gkz217] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 03/15/2019] [Accepted: 03/28/2019] [Indexed: 12/24/2022] Open
Abstract
Microbes have the unique ability to acquire immunological memories from mobile genetic invaders to protect themselves from predation. To confer CRISPR resistance, new spacers need to be compatible with a targeting requirement in the invader's DNA called the protospacer adjacent motif (PAM). Many CRISPR systems encode Cas4 proteins to ensure new spacers are integrated that meet this targeting prerequisite. Here we report that a gene fusion between cas4 and cas1 from the Geobacter sulfurreducens I-U CRISPR-Cas system is capable of introducing functional spacers carrying interference proficient TTN PAM sequences at much higher frequencies than unfused Cas4 adaptation modules. Mutations of Cas4-domain catalytic residues resulted in dramatically decreased naïve and primed spacer acquisition, and a loss of PAM selectivity showing that the Cas4 domain controls Cas1 activity. We propose the fusion gene evolved to drive the acquisition of only PAM-compatible spacers to optimize CRISPR interference.
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Affiliation(s)
- Cristóbal Almendros
- Kavli Institute of Nanoscience, Department of Bionanoscience, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, Netherlands
| | - Franklin L Nobrega
- Kavli Institute of Nanoscience, Department of Bionanoscience, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, Netherlands
| | - Rebecca E McKenzie
- Kavli Institute of Nanoscience, Department of Bionanoscience, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, Netherlands
| | - Stan J J Brouns
- Kavli Institute of Nanoscience, Department of Bionanoscience, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, Netherlands.,Laboratory of Microbiology, Wageningen University, Stippeneng 4, 6708 WE Wageningen, Netherlands
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Lam TJ, Ye Y. Long reads reveal the diversification and dynamics of CRISPR reservoir in microbiomes. BMC Genomics 2019; 20:567. [PMID: 31288753 PMCID: PMC6617893 DOI: 10.1186/s12864-019-5922-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Accepted: 06/21/2019] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Sequencing of microbiomes has accelerated the characterization of the diversity of CRISPR-Cas immune systems. However, the utilization of next generation short read sequences for the characterization of CRISPR-Cas dynamics remains limited due to the repetitive nature of CRISPR arrays. CRISPR arrays are comprised of short spacer segments (derived from invaders' genomes) interspaced between flanking repeat sequences. The repetitive structure of CRISPR arrays poses a computational challenge for the accurate assembly of CRISPR arrays from short reads. In this paper we evaluate the use of long read sequences for the analysis of CRISPR-Cas system dynamics in microbiomes. RESULTS We analyzed a dataset of Illumina's TruSeq Synthetic Long-Reads (SLR) derived from a gut microbiome. We showed that long reads captured CRISPR spacers at a high degree of redundancy, which highlights the spacer conservation of spacer sharing CRISPR variants, enabling the study of CRISPR array dynamics in ways difficult to achieve though short read sequences. We introduce compressed spacer graphs, a visual abstraction of spacer sharing CRISPR arrays, to provide a simplified view of complex organizational structures present within CRISPR array dynamics. Utilizing compressed spacer graphs, several key defining characteristics of CRISPR-Cas system dynamics were observed including spacer acquisition and loss events, conservation of the trailer end spacers, and CRISPR arrays' directionality (transcription orientation). Other result highlights include the observation of intense array contraction and expansion events, and reconstruction of a full-length genome for a potential invader (Faecalibacterium phage) based on identified spacers. CONCLUSION We demonstrate in an in silico system that long reads provide the necessary context for characterizing the organization of CRISPR arrays in a microbiome, and reveal dynamic and evolutionary features of CRISPR-Cas systems in a microbial population.
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Affiliation(s)
- Tony J Lam
- School of Informatics, Computing, and Engineering Indiana University, Bloomington, 47408, IN, USA
| | - Yuzhen Ye
- School of Informatics, Computing, and Engineering Indiana University, Bloomington, 47408, IN, USA.
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