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Ishii M, Yamada T, Ohata S. An efficient gene targeting system using Δku80 and functional analysis of Cyp51A in Trichophyton rubrum. AMB Express 2024; 14:96. [PMID: 39215862 PMCID: PMC11365917 DOI: 10.1186/s13568-024-01755-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2024] [Accepted: 08/14/2024] [Indexed: 09/04/2024] Open
Abstract
Trichophyton rubrum is one of the most frequently isolated fungi in patients with dermatophytosis. Despite its clinical significance, the molecular mechanisms of drug resistance and pathogenicity of T. rubrum remain to be elucidated because of the lack of genetic tools, such as efficient gene targeting systems. In this study, we generated a T. rubrum strain that lacks the nonhomologous end-joining-related gene ku80 (Δku80) and then developed a highly efficient genetic recombination system with gene targeting efficiency that was 46 times higher than that using the wild-type strain. Cyp51A and Cyp51B are 14-α-lanosterol demethylase isozymes in T. rubrum that promote ergosterol biosynthesis and are the targets of azole antifungal drugs. The expression of cyp51A mRNA was induced by the addition of the azole antifungal drug efinaconazole, whereas no such induction was detected for cyp51B, suggesting that Cyp51A functions as an azole-responsive Cyp51 isozyme. To explore the contribution of Cyp51A to susceptibility to azole drugs, the neomycin phosphotransferase (nptII) gene cassette was inserted into the cyp51A 3'-untranslated region of Δku80 to destabilize the mRNA of cyp51A. In this mutant, the induction of cyp51A mRNA expression by efinaconazole was diminished. The minimum inhibitory concentration for several azole drugs of this strain was reduced, suggesting that dermatophyte Cyp51A contributes to the tolerance for azole drugs. These findings suggest that an efficient gene targeting system using Δku80 in T. rubrum is applicable for analyzing genes encoding drug targets.
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Affiliation(s)
- Masaki Ishii
- Research Institute of Pharmaceutical Sciences, Faculty of Pharmacy, Musashino University, Tokyo, 202-8585, Japan.
| | - Tsuyoshi Yamada
- Teikyo University Institute of Medical Mycology, Teikyo University, Hachioji, Tokyo, 192-0395, Japan
- Asia International Institute of Infectious Disease Control, Teikyo University, Tokyo, Japan
| | - Shinya Ohata
- Research Institute of Pharmaceutical Sciences, Faculty of Pharmacy, Musashino University, Tokyo, 202-8585, Japan.
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Fritsche S, Reinfurt A, Fronek F, Steiger MG. NHEJ and HDR can occur simultaneously during gene integration into the genome of Aspergillus niger. Fungal Biol Biotechnol 2024; 11:10. [PMID: 39103967 DOI: 10.1186/s40694-024-00180-7] [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: 04/23/2024] [Accepted: 07/07/2024] [Indexed: 08/07/2024] Open
Abstract
Non-homologous end joining (NHEJ) and homology-directed repair (HDR) are two mechanisms in filamentous fungi to repair DNA damages. NHEJ is the dominant response pathway to rapidly join DNA double-strand breaks, but often leads to insertions or deletions. On the other hand, HDR is more precise and utilizes a homologous DNA template to restore the damaged sequence. Both types are exploited in genetic engineering approaches ranging from knock-out mutations to precise sequence modifications.In this study, we evaluated the efficiency of an HDR based gene integration system designed for the pyrG locus of Aspergillus niger. While gene integration was achieved at a rate of 91.4%, we also discovered a mixed-type repair (MTR) mechanism with simultaneous repair of a Cas9-mediated double-strand break by both NHEJ and HDR. In 20.3% of the analyzed transformants the donor DNA was integrated by NHEJ at the 3' end and by HDR at the 5' end of the double-strand break. Furthermore, sequencing of the locus revealed different DNA repair mechanisms at the site of the NHEJ event.Together, the results support the applicability of the genome integration system and a novel DNA repair type with implication on the diversity of genetic modifications in filamentous fungi.
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Affiliation(s)
- Susanne Fritsche
- Austrian Centre of Industrial Biotechnology, Muthgasse 18, Vienna, Austria
- Institute of Chemical, Environmental and Bioscience Engineering, Research Group Biochemistry, Technische Universität Wien, Gumpendorferstrasse 1A, Vienna, 1060, Austria
| | - Aline Reinfurt
- Austrian Centre of Industrial Biotechnology, Muthgasse 18, Vienna, Austria
- Institute of Chemical, Environmental and Bioscience Engineering, Research Group Biochemistry, Technische Universität Wien, Gumpendorferstrasse 1A, Vienna, 1060, Austria
| | - Felix Fronek
- Austrian Centre of Industrial Biotechnology, Muthgasse 18, Vienna, Austria
- Institute of Chemical, Environmental and Bioscience Engineering, Research Group Biochemistry, Technische Universität Wien, Gumpendorferstrasse 1A, Vienna, 1060, Austria
| | - Matthias G Steiger
- Austrian Centre of Industrial Biotechnology, Muthgasse 18, Vienna, Austria.
- Institute of Chemical, Environmental and Bioscience Engineering, Research Group Biochemistry, Technische Universität Wien, Gumpendorferstrasse 1A, Vienna, 1060, Austria.
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Hatinguais R, Leaves I, Brown GD, Brown AJP, Brock M, Peres da Silva R. CRISPR-based tools for targeted genetic manipulation in pathogenic Sporothrix species. Microbiol Spectr 2023; 11:e0507822. [PMID: 37707447 PMCID: PMC10581184 DOI: 10.1128/spectrum.05078-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 07/11/2023] [Indexed: 09/15/2023] Open
Abstract
Sporothrix brasiliensis is an emerging fungal pathogen frequently associated with zoonotic transmission of sporotrichosis by contaminated cats. Within 25 years, the disease has spread not only throughout Brazil but now to neighboring countries in Latin America. Thermo-dimorphism, melanin, glycans, adhesins, and secreted vesicles have been associated with the ability of Sporothrix species to cause disease in the mammalian host. Although certain virulence factors have been proposed as potential determinants for sporotrichosis, the scarcity of molecular tools for performing reverse genetics in Sporothrix has significantly impeded the dissection of mechanisms underlying the disease. Here, we demonstrate that PEG-mediated protoplast transformation is a powerful method for heterologous gene expression in S. brasiliensis, S. schenckii, and S. chilensis. Combined with CRISPR/Cas9 gene editing, this transformation protocol enabled the deletion of the putative DHN-melanin synthase gene pks1, which is a proposed virulence factor of Sporothrix species. To improve in locus integration of deletion constructs, we deleted the KU80 homolog that is critical for non-homologous end-joining DNA repair. The use of Δku80 strains from S. brasiliensis enhanced homologous-directed repair during transformation resulting in increased targeted gene deletion in combination with CRISPR/Cas9. In conclusion, our CRISPR/Cas9-based transformation protocol provides an efficient tool for targeted gene manipulation in Sporothrix species. IMPORTANCE Sporotrichosis caused by Sporothrix brasiliensis is a disease that requires long periods of treatment and is rapidly spreading across Latin America. The virulence of this fungus and the surge of atypical and more severe presentations of the disease raise the need for an understanding of the molecular mechanisms underlying sporotrichosis, as well as the development of better diagnostics and antifungal therapies. By developing molecular tools for accurate genetic manipulation in Sporothrix, this study addresses the paucity of reliable and reproducible tools for stable genetic engineering of Sporothrix species, which has represented a major obstacle for studying the virulence determinants and their roles in the establishment of sporotrichosis.
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Affiliation(s)
- Remi Hatinguais
- Medical Research Council Centre for Medical Mycology, University of Exeter, Exeter, United Kingdom
| | - Ian Leaves
- Medical Research Council Centre for Medical Mycology, University of Exeter, Exeter, United Kingdom
| | - Gordon D. Brown
- Medical Research Council Centre for Medical Mycology, University of Exeter, Exeter, United Kingdom
| | - Alistair J. P. Brown
- Medical Research Council Centre for Medical Mycology, University of Exeter, Exeter, United Kingdom
| | - Matthias Brock
- Fungal Biology Group, School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Roberta Peres da Silva
- Medical Research Council Centre for Medical Mycology, University of Exeter, Exeter, United Kingdom
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Acs-Szabo L, Papp LA, Takacs S, Miklos I. Disruption of the Schizosaccharomyces japonicus lig4 Disturbs Several Cellular Processes and Leads to a Pleiotropic Phenotype. J Fungi (Basel) 2023; 9:jof9050550. [PMID: 37233261 DOI: 10.3390/jof9050550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 04/15/2023] [Accepted: 05/05/2023] [Indexed: 05/27/2023] Open
Abstract
Gene targeting is a commonly used method to reveal the function of genes. Although it is an attractive tool for molecular studies, it can frequently be a challenge because its efficiency can be low and it requires the screening of a large number of transformants. Generally, these problems originate from the elevated level of ectopic integration caused by non-homologous DNA end joining (NHEJ). To eliminate this problem, NHEJ-related genes are frequently deleted or disrupted. Although these manipulations can improve gene targeting, the phenotype of the mutant strains raised the question of whether mutations have side effects. The aim of this study was to disrupt the lig4 gene in the dimorphic fission yeast, S. japonicus, and investigate the phenotypic changes of the mutant strain. The mutant cells have shown various phenotypic changes, such as increased sporulation on complete medium, decreased hyphal growth, faster chronological aging, and higher sensitivity to heat shock, UV light, and caffeine. In addition, higher flocculation capacity has been observed, especially at lower sugar concentrations. These changes were supported by transcriptional profiling. Many genes belonging to metabolic and transport processes, cell division, or signaling had altered mRNA levels compared to the control strain. Although the disruption improved the gene targeting, we assume that the lig4 inactivation can cause unexpected physiological side effects, and we have to be very careful with the manipulations of the NHEJ-related genes. To reveal the exact mechanisms behind these changes, further investigations are required.
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Affiliation(s)
- Lajos Acs-Szabo
- Department of Genetics and Applied Microbiology, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
| | - Laszlo Attila Papp
- Department of Genetics and Applied Microbiology, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
| | - Szonja Takacs
- Department of Genetics and Applied Microbiology, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
| | - Ida Miklos
- Department of Genetics and Applied Microbiology, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, 4032 Debrecen, Hungary
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Advances and Challenges in CRISPR/Cas-Based Fungal Genome Engineering for Secondary Metabolite Production: A Review. J Fungi (Basel) 2023; 9:jof9030362. [PMID: 36983530 PMCID: PMC10058990 DOI: 10.3390/jof9030362] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Revised: 03/10/2023] [Accepted: 03/14/2023] [Indexed: 03/18/2023] Open
Abstract
Fungi represent an important source of bioactive secondary metabolites (SMs), which have wide applications in many fields, including medicine, agriculture, human health, and many other industries. The genes involved in SM biosynthesis are usually clustered adjacent to each other into a region known as a biosynthetic gene cluster (BGC). The recent advent of a diversity of genetic and genomic technologies has facilitated the identification of many cryptic or uncharacterized BGCs and their associated SMs. However, there are still many challenges that hamper the broader exploration of industrially important secondary metabolites. The recent advanced CRISPR/Cas system has revolutionized fungal genetic engineering and enabled the discovery of novel bioactive compounds. In this review, we firstly introduce fungal BGCs and their relationships with associated SMs, followed by a brief summary of the conventional strategies for fungal genetic engineering. Next, we introduce a range of state-of-the-art CRISPR/Cas-based tools that have been developed and review recent applications of these methods in fungi for research on the biosynthesis of SMs. Finally, the challenges and limitations of these CRISPR/Cas-based systems are discussed and directions for future research are proposed in order to expand their applications and improve efficiency for fungal genetic engineering.
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Favilla LD, Herman TS, Goersch CDS, de Andrade RV, Felipe MSS, Bocca AL, Fernandes L. Expanding the Toolbox for Functional Genomics in Fonsecaea pedrosoi: The Use of Split-Marker and Biolistic Transformation for Inactivation of Tryptophan Synthase ( trpB) Gene. J Fungi (Basel) 2023; 9:jof9020224. [PMID: 36836338 PMCID: PMC9963410 DOI: 10.3390/jof9020224] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Revised: 01/27/2023] [Accepted: 01/31/2023] [Indexed: 02/11/2023] Open
Abstract
Chromoblastomycosis (CBM) is a disease caused by several dematiaceous fungi from different genera, and Fonsecaea is the most common which has been clinically isolated. Genetic transformation methods have recently been described; however, molecular tools for the functional study of genes have been scarcely reported for those fungi. In this work, we demonstrated that gene deletion and generation of the null mutant by homologous recombination are achievable for Fonsecaea pedrosoi by the use of two approaches: use of double-joint PCR for cassette construction, followed by delivery of the split-marker by biolistic transformation. Through in silico analyses, we identified that F. pedrosoi presents the complete enzymatic apparatus required for tryptophan (trp) biosynthesis. The gene encoding a tryptophan synthase trpB -which converts chorismate to trp-was disrupted. The ΔtrpB auxotrophic mutant can grow with external trp supply, but germination, viability of conidia, and radial growth are defective compared to the wild-type and reconstituted strains. The use of 5-FAA for selection of trp- phenotypes and for counter-selection of strains carrying the trp gene was also demonstrated. The molecular tools for the functional study of genes, allied to the genetic information from genomic databases, significantly boost our understanding of the biology and pathogenicity of CBM causative agents.
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Affiliation(s)
- Luísa Dan Favilla
- Laboratory of Applied Immunology, Institute of Biology, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Federal District, Brasilia 70910-900, Brazil
- Graduate Program in Molecular Biology, Institute of Biology, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Federal District, Brasilia 70910-900, Brazil
| | - Tatiana Sobianski Herman
- Laboratory of Applied Immunology, Institute of Biology, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Federal District, Brasilia 70910-900, Brazil
- Graduate Program in Molecular Patology, Faculty of Medicine, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Federal District, Brasilia 70910-900, Brazil
| | - Camila da Silva Goersch
- Laboratory of Applied Immunology, Institute of Biology, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Federal District, Brasilia 70910-900, Brazil
- Graduate Program in Microbial Biology, Institute of Biology, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Federal District, Brasilia 70910-900, Brazil
| | - Rosangela Vieira de Andrade
- Graduate Program of Genomic Sciences and Biotechnology, Catholic University of Brasilia, Campus Asa Norte, Asa Norte, Federal District, Taguatinga 70790-160, Brazil
| | - Maria Sueli Soares Felipe
- Graduate Program of Genomic Sciences and Biotechnology, Catholic University of Brasilia, Campus Asa Norte, Asa Norte, Federal District, Taguatinga 70790-160, Brazil
| | - Anamélia Lorenzetti Bocca
- Laboratory of Applied Immunology, Institute of Biology, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Federal District, Brasilia 70910-900, Brazil
- Graduate Program in Molecular Biology, Institute of Biology, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Federal District, Brasilia 70910-900, Brazil
- Graduate Program in Molecular Patology, Faculty of Medicine, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Federal District, Brasilia 70910-900, Brazil
| | - Larissa Fernandes
- Laboratory of Applied Immunology, Institute of Biology, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Federal District, Brasilia 70910-900, Brazil
- Graduate Program in Microbial Biology, Institute of Biology, Campus Darcy Ribeiro, University of Brasília, Asa Norte, Federal District, Brasilia 70910-900, Brazil
- Centro Metropolitano, Faculty of Ceilândia, Campus UnB Ceilândia, University of Brasília, Ceilândia Sul, Federal District, Brasilia 72220-275, Brazil
- Correspondence:
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Chen L, Chen B, Zhu QH, Zhang X, Sun T, Liu F, Yang Y, Sun J, Li Y. Identification of sugar transporter genes and their roles in the pathogenicity of Verticillium dahliae on cotton. FRONTIERS IN PLANT SCIENCE 2023; 14:1123523. [PMID: 36778686 PMCID: PMC9910176 DOI: 10.3389/fpls.2023.1123523] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 01/09/2023] [Indexed: 06/18/2023]
Abstract
INTRODUCTION Verticillium wilt (VW) caused by Verticillium dahliae is a soil-borne vascular fungal disease that severely affects cotton yield and fiber quality. Sugar metabolism plays an important role in the growth and pathogenicity of V. dahliae. However, limited information is known about the sugar transporter genes and their roles in the growth and pathogenicity of V. dahliae. METHOD In this study, genome-wide identification of sugar transporter genes in V. dahliae was conducted and the expression profiles of these genes in response to root exudates from cotton varieties susceptible or resistant to V. dahliae were investigated based on RNA-seq data. Tobacco Rattle Virus-based host-induced gene silencing (TRV-based HIGS) and artificial small interfering RNAs (asiRNAs) were applied to investigate the function of candidate genes involved in the growth and pathogenic process of V. dahliae. RESULTS A total of 65 putative sugar transporter genes were identified and clustered into 8 Clades. Of the 65 sugar transporter genes, 9 were found to be induced only by root exudates from the susceptible variety, including VdST3 and VdST12 that were selected for further functional study. Silencing of VdST3 or VdST12 in host plants by TRV-based HIGS reduced fungal biomass and enhanced cotton resistance against V. dahliae. Additionally, silencing of VdST12 and VdST3 by feeding asiRNAs targeting VdST12 (asiR815 or asiR1436) and VdST3 (asiR201 or asiR1238) inhibited fungal growth, exhibiting significant reduction in hyphae and colony diameter, with a more significant effect observed for the asiRNAs targeting VdST12. The inhibitory effect of asiRNAs on the growth of V. dahliae was enhanced with the increasing concentration of asiRNAs. Silencing of VdST12 by feeding asiR815+asiR1436 significantly decreased the pathogenicity of V. dahliae. DISCUSSION The results suggest that VdST3 and VdST12 are sugar transporter genes required for growth and pathogenicity of V. dahliae and that asiRNA is a valuable tool for functional characterization of V. dahliae genes.
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Affiliation(s)
- Lihua Chen
- The Key Laboratory of Oasis Eco-agriculture, Agriculture College, Shihezi University, Shihezi, Xinjiang, China
| | - Bin Chen
- The Key Laboratory of Oasis Eco-agriculture, Agriculture College, Shihezi University, Shihezi, Xinjiang, China
| | | | - Xinyu Zhang
- The Key Laboratory of Oasis Eco-agriculture, Agriculture College, Shihezi University, Shihezi, Xinjiang, China
| | - Tiange Sun
- The Key Laboratory of Oasis Eco-agriculture, Agriculture College, Shihezi University, Shihezi, Xinjiang, China
| | - Feng Liu
- The Key Laboratory of Oasis Eco-agriculture, Agriculture College, Shihezi University, Shihezi, Xinjiang, China
| | - Yonglin Yang
- Cotton Research Institute, Shihezi Academy of Agricultural Sciences, Shihezi, China
| | - Jie Sun
- The Key Laboratory of Oasis Eco-agriculture, Agriculture College, Shihezi University, Shihezi, Xinjiang, China
| | - Yanjun Li
- The Key Laboratory of Oasis Eco-agriculture, Agriculture College, Shihezi University, Shihezi, Xinjiang, China
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Woodcraft C, Chooi YH, Roux I. The expanding CRISPR toolbox for natural product discovery and engineering in filamentous fungi. Nat Prod Rep 2023; 40:158-173. [PMID: 36205232 DOI: 10.1039/d2np00055e] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Covering: up to May 2022Fungal genetics has transformed natural product research by enabling the elucidation of cryptic metabolites and biosynthetic steps. The enhanced capability to add, subtract, modulate, and rewrite genes via CRISPR/Cas technologies has opened up avenues for the manipulation of biosynthetic gene clusters across diverse filamentous fungi. This review discusses the innovative and diverse strategies for fungal natural product discovery and engineering made possible by CRISPR/Cas-based tools. We also provide a guide into multiple angles of CRISPR/Cas experiment design, and discuss current gaps in genetic tool development for filamentous fungi and the promising opportunities for natural product research.
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Affiliation(s)
- Clara Woodcraft
- School of Molecular Sciences, The University of Western Australia, Perth, WA 6009, Australia.
| | - Yit-Heng Chooi
- School of Molecular Sciences, The University of Western Australia, Perth, WA 6009, Australia.
| | - Indra Roux
- School of Molecular Sciences, The University of Western Australia, Perth, WA 6009, Australia.
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Guo R, Liu T, Guo C, Chen G, Fan J, Zhang Q. Carotenoid biosynthesis is associated with low-temperature adaptation in Rhodosporidium kratochvilovae. BMC Microbiol 2022; 22:319. [PMID: 36564716 PMCID: PMC9789556 DOI: 10.1186/s12866-022-02728-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 12/08/2022] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Low temperatures greatly limit the growth of microorganisms. Low-temperature adaptation in microorganisms involves multiple mechanisms. Carotenoids are naturally occurring lipid-soluble pigments that act as antioxidants and protect cells and tissues from the harmful effects of free radicals and singlet oxygen. However, studies on the regulation of carotenoid biosynthesis at low temperatures in microorganisms are limited. In this study, we investigated the correlation between carotenoids and low-temperature adaptation in the cold-adapted strain of Rhodosporidium kratochvilovae YM25235. RESULTS Carotenoid biosynthesis in YM25235 was inhibited by knocking out the bifunctional lycopene cyclase/phytoene synthase gene (RKCrtYB) using the established CRISPR/Cas9 gene-editing system based on endogenous U6 promoters. The carotenoids were extracted with acetone, and the content and composition of the carotenoids were analyzed by spectrophotometry and HPLC. Then, the levels of reactive oxygen species (ROS) and the growth rate in YM25235 were determined at a low temperature. The results indicated that the carotenoid biosynthesis and ROS levels were increased in the YM25235 strain at a low temperature and inhibition of carotenoid biosynthesis was associated with higher ROS levels and a significant decrease in the growth rate of YM25235 at a low temperature. CONCLUSIONS The regulation of carotenoid biosynthesis was associated with low-temperature adaptation in YM25235. Our findings provided a strong foundation for conducting further studies on the mechanism by which YM25235 can adapt to low-temperature stress.
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Affiliation(s)
- Rui Guo
- grid.218292.20000 0000 8571 108XFaculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500 China
| | - Tao Liu
- grid.218292.20000 0000 8571 108XFaculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500 China
| | - Caina Guo
- grid.218292.20000 0000 8571 108XFaculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500 China
| | - Gongshui Chen
- grid.218292.20000 0000 8571 108XFaculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500 China
| | - Jingdie Fan
- grid.218292.20000 0000 8571 108XFaculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500 China
| | - Qi Zhang
- grid.218292.20000 0000 8571 108XFaculty of Life Science and Technology, Kunming University of Science and Technology, Kunming, 650500 China
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Pareek M, Hegedüs B, Hou Z, Csernetics Á, Wu H, Virágh M, Sahu N, Liu XB, Nagy L. Preassembled Cas9 Ribonucleoprotein-Mediated Gene Deletion Identifies the Carbon Catabolite Repressor and Its Target Genes in Coprinopsis cinerea. Appl Environ Microbiol 2022; 88:e0094022. [PMID: 36374019 PMCID: PMC9746306 DOI: 10.1128/aem.00940-22] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2022] [Accepted: 10/11/2022] [Indexed: 11/16/2022] Open
Abstract
Cre1 is an important transcription factor that regulates carbon catabolite repression (CCR) and is widely conserved across fungi. The cre1 gene has been extensively studied in several Ascomycota species, whereas its role in gene expression regulation in the Basidiomycota species remains poorly understood. Here, we identified and investigated the role of cre1 in Coprinopsis cinerea, a basidiomycete model mushroom that can efficiently degrade lignocellulosic plant wastes. We used a rapid and efficient gene deletion approach based on PCR-amplified split-marker DNA cassettes together with in vitro assembled Cas9-guide RNA ribonucleoproteins (Cas9 RNPs) to generate C. cinerea cre1 gene deletion strains. Gene expression profiling of two independent C. cinerea cre1 mutants showed significant deregulation of carbohydrate metabolism, plant cell wall degrading enzymes (PCWDEs), plasma membrane transporter-related and several transcription factor-encoding genes, among others. Our results support the notion that, like reports in the ascomycetes, Cre1 of C. cinerea orchestrates CCR through a combined regulation of diverse genes, including PCWDEs, transcription factors that positively regulate PCWDEs, and membrane transporters which could import simple sugars that can induce the expression of PWCDEs. Somewhat paradoxically, though in accordance with other Agaricomycetes, genes related to lignin degradation were mostly downregulated in cre1 mutants, indicating they fall under different regulation than other PCWDEs. The gene deletion approach and the data presented here will expand our knowledge of CCR in the Basidiomycota and provide functional hypotheses on genes related to plant biomass degradation. IMPORTANCE Mushroom-forming fungi include some of the most efficient lignocellulosic plant biomass degraders. They degrade dead plant materials by a battery of lignin-, cellulose-, hemicellulose-, and pectin-degrading enzymes, the encoding genes of which are under tight transcriptional control. One of the highest-level regulations of these metabolic enzymes is known as carbon catabolite repression, which is orchestrated by the transcription factor Cre1, and ensures that costly lignocellulose-degrading enzyme genes are expressed only when simple carbon sources (e.g., glucose) are not available. Here, we identified the Cre1 ortholog in a litter decomposer Agaricomycete, Coprinopsis cinerea, knocked it out, and characterized transcriptional changes in the mutants. We identified several dozen lignocellulolytic enzyme genes as well as membrane transporters and other transcription factors as putative target genes of C. cinerea cre1. These results extend knowledge on carbon catabolite repression to litter decomposer Basidiomycota.
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Affiliation(s)
- Manish Pareek
- Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
| | - Botond Hegedüs
- Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
| | - Zhihao Hou
- Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
| | - Árpád Csernetics
- Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
| | - Hongli Wu
- Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
| | - Máté Virágh
- Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
| | - Neha Sahu
- Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
| | - Xiao-Bin Liu
- Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
| | - László Nagy
- Institute of Biochemistry, Biological Research Centre, Szeged, Hungary
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Cai W, Chen Y, Zhang L, Fang X, Wang W. A three-gene cluster in Trichoderma reesei reveals a potential role of dmm2 in DNA repair and cellulase production. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:34. [PMID: 35351200 PMCID: PMC8966179 DOI: 10.1186/s13068-022-02132-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Accepted: 03/19/2022] [Indexed: 12/03/2022]
Abstract
Background The ascomycete Trichoderma reesei is one of the most efficient industrial producers of cellulase. Gene targeting by homologous recombination is a key technique for improving strains and constructing mutants. In T. reesei, tku70 (homologous to human KU70) was deleted to block non-homologous end-joining, which led to 95% of transformants exhibiting homologous recombination. Results Two genes located in close proximity to tku70 were identified: the ferrochelatase gene hem8 (tre78582, homologous to Aspergillus niger hemH and Cryptococcus neoformans HEM15) and a putative DNA methylation modulator-2 gene dmm2 (tre108087, homologous to Neurospora crassa dmm-2). Genome-wide surveys of 324 sequenced fungal genomes revealed that the homologues of the three genes of interest are encoded in tandem in most Sordariomycetes. The expression of this three-gene cluster is regulated by blue light. The roles of these three genes were analyzed via deletion and complementation tests. The gene hem8 was originally described as a novel and highly distinct auxotrophic marker in T. reesei and we found that the product protein, HEM8, catalyzes the final step in heme biosynthesis from highly photoreactive porphyrins. The lethal phenotype of the hem8 deletion could be overcome by hematin supplementation. We also studied the functions of tku70 and dmm2 in DNA repair using mutagen sensitivity experiments. We found that the Δtku70 strain showed increased sensitivity to bleomycin, which induces DNA double-strand breaks, and that the Δdmm2 strain was sensitive to bleomycin, camptothecin (an inhibitor of type I topoisomerases), and hydroxyurea (a deoxynucleotide synthesis inhibitor). The double-mutant Δtku70&dmm2 showed higher sensitivity to hydroxyurea, camptothecin, and bleomycin than either of the single mutants. Knockout of dmm2 significantly increased cellulase production. Conclusions Our data show, for the first time, that ferrochelatase encoded by hem8 catalyzes the final step in heme biosynthesis from highly photoreactive porphyrins and that dmm2 encodes a putative DNA methylation modulator-2 protein related to DNA repair and cellulase expression in T. reesei. Our data provide important insights into the roles of this three-gene cluster in T. reesei and other Sordariomycetes and show that the DNA methylation modulator DMM2 affects cellulase gene expression in T. reesei. Supplementary Information The online version contains supplementary material available at 10.1186/s13068-022-02132-y.
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Pant S, Ritika, Nag P, Ghati A, Chakraborty D, Maximiano MR, Franco OL, Mandal AK, Kuila A. Employment of the CRISPR/Cas9 system to improve cellulase production in Trichoderma reesei. Biotechnol Adv 2022; 60:108022. [PMID: 35870723 DOI: 10.1016/j.biotechadv.2022.108022] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2022] [Revised: 07/05/2022] [Accepted: 07/17/2022] [Indexed: 12/27/2022]
Abstract
Trichoderma reesei has been explored intensively in the laboratory and on an industrial scale for its highly potent cellulase secretion machinery since its characterization over 70 years ago. Emergence of new genetic tools over the past decade has strengthened the understanding of mechanism involved in transcription of cellulase genes in fungi and provided a boost to edit them at molecular level. Since several transcriptional factors work synergistically for cellulase expression in fungi; engineering of cellulase secretome for enhanced cellulase titer require combined manipulation of these factors. In the same context, CRISPR/Cas9 has emerged as a powerful, versatile genetic engineering tool for multiplex gene editing in fungi. It is true that considerable efforts with CRISPR technologies have largely developed fungal genetic engineering, but its application in fungi is still challenging and limited. The present review illustrates the precision, strengths and challenges of using CRISPR/Cas9 technology for cellulase engineering in T. reesei, highlighting key strategies that could be employed for strain improvement.
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Affiliation(s)
- Shailja Pant
- Department of Bioscience and Biotechnology, Banasthali Vidyapith, Rajasthan 304022, India
| | - Ritika
- Department of Bioscience and Biotechnology, Banasthali Vidyapith, Rajasthan 304022, India
| | - Piyali Nag
- Department of Microbiology, Barrackpore Rastraguru Surendranath College, Barrackpore, Kolkata 700120, India
| | - Amit Ghati
- Department of Microbiology, Barrackpore Rastraguru Surendranath College, Barrackpore, Kolkata 700120, India.
| | - Dipjyoti Chakraborty
- Department of Bioscience and Biotechnology, Banasthali Vidyapith, Rajasthan 304022, India
| | - Mariana Rocha Maximiano
- Centro de Análises Proteômicas e Bioquímicas, Pós-Graduação em Ciências Genômicas e Biotecnologia Universidade Católica de Brasília, Brasília, DF, Brazil; S-Inova Biotech, Pós-Graduação em Biotecnologia, Universidade Católica Dom Bosco, Campo Grande, MS, Brazil
| | - Octavio Luiz Franco
- Centro de Análises Proteômicas e Bioquímicas, Pós-Graduação em Ciências Genômicas e Biotecnologia Universidade Católica de Brasília, Brasília, DF, Brazil; S-Inova Biotech, Pós-Graduação em Biotecnologia, Universidade Católica Dom Bosco, Campo Grande, MS, Brazil
| | - Amit Kumar Mandal
- Centre for Nanotechnology Sciences & Chemical Biology Laboratory, Department of Sericulture, Raiganj University, Raiganj, 733134, India
| | - Arindam Kuila
- Department of Bioscience and Biotechnology, Banasthali Vidyapith, Rajasthan 304022, India.
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Genome editing using preassembled CRISPR-Cas9 ribonucleoprotein complexes in Fusarium graminearum. PLoS One 2022; 17:e0268855. [PMID: 35657788 PMCID: PMC9165886 DOI: 10.1371/journal.pone.0268855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 05/09/2022] [Indexed: 11/19/2022] Open
Abstract
Genome editing using the clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9) system has greatly facilitated the genetic analysis of fungal pathogens. The head blight fungus, Fusarium graminearum, causes destructive losses of economically important cereal crops. The recent development of the CRISPR-Cas9 system for use with F. graminearum has enabled more efficient genome editing. In this study, we described a CRISPR-Cas9-based genome-editing tool for the direct delivery of preassembled Cas9 ribonucleoproteins (RNPs) into the protoplasts of F. graminearum. The use of RNPs significantly increased both the number of transformants and percentage of transformants in which the target gene was successfully replaced with a selectable marker. We showed that a single double-strand DNA break mediated by the Cas9 ribonucleoprotein was sufficient for gene deletion. In addition, short-homology recombination required only 50 base pair regions flanking the target gene. The high efficiency of Cas9 RNPs enables large-scale functional analysis, the identification of essential genes, and gene deletion that is difficult with conventional methods. We expect that our approach will accelerate genetic studies of F. graminearum.
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Navarrete C, Estrada M, Martínez JL. Debaryomyces hansenii: an old acquaintance for a fresh start in the era of the green biotechnology. World J Microbiol Biotechnol 2022; 38:99. [PMID: 35482161 PMCID: PMC9050785 DOI: 10.1007/s11274-022-03280-x] [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: 02/04/2022] [Accepted: 04/05/2022] [Indexed: 11/18/2022]
Abstract
The halophilic yeast Debaryomyces hansenii has been studied for several decades, serving as eukaryotic model for understanding salt and osmotic tolerance. Nevertheless, lack of consensus among different studies is found and, sometimes, contradictory information derived from studies performed in very diverse conditions. These two factors hampered its establishment as the key biotechnological player that was called to be in the past decade. On top of that, very limited (often deficient) engineering tools are available for this yeast. Fortunately Debaryomyces is again gaining momentum and recent advances using highly instrumented lab scale bioreactors, together with advanced –omics and HT-robotics, have revealed a new set of interesting results. Those forecast a very promising future for D. hansenii in the era of the so-called green biotechnology. Moreover, novel genetic tools enabling precise gene editing on this yeast are now available. In this review, we highlight the most recent developments, which include the identification of a novel gene implicated in salt tolerance, a newly proposed survival mechanism for D. hansenii at very high salt and limiting nutrient concentrations, and its utilization as production host in biotechnological processes.
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Affiliation(s)
- Clara Navarrete
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads Building 223, 2800, Kgs. Lyngby, Denmark
| | - Mònica Estrada
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads Building 223, 2800, Kgs. Lyngby, Denmark
| | - José L Martínez
- Section of Synthetic Biology (DTU Bioengineering), Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads Building 223, 2800, Kgs. Lyngby, Denmark.
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Futagami T. The white koji fungus Aspergillus luchuensis mut. kawachii. Biosci Biotechnol Biochem 2022; 86:574-584. [PMID: 35238900 DOI: 10.1093/bbb/zbac033] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 02/24/2022] [Indexed: 11/13/2022]
Abstract
The white koji fungus, Aspergillus luchuensis mut. kawachii, is used in the production of shochu, a traditional Japanese distilled spirit. White koji fungus plays an important role in the shochu production process by supplying amylolytic enzymes such as α-amylase and glucoamylase. These enzymes convert starch contained in primary ingredients such as rice, barley, buckwheat, and sweet potato into glucose, which is subsequently utilized by the yeast Saccharomyces cerevisiae to produce ethanol. White koji fungus also secretes large amounts of citric acid, which lowers the pH of the shochu mash, thereby preventing the growth of undesired microbes and enabling stable production of shochu in relatively warm regions of Japan. This review describes the historical background, research tools, and recent advances in studies of the mechanism of citric acid production by white koji fungus.
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Affiliation(s)
- Taiki Futagami
- Education and Research Center for Fermentation Studies, Faculty of Agriculture, Kagoshima University, Kagoshima, Japan.,United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima, Japan
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McCarthy HM, Tarallo M, Mesarich CH, McDougal RL, Bradshaw RE. Targeted Gene Mutations in the Forest Pathogen Dothistroma septosporum Using CRISPR/Cas9. PLANTS (BASEL, SWITZERLAND) 2022; 11:plants11081016. [PMID: 35448744 PMCID: PMC9025729 DOI: 10.3390/plants11081016] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 04/04/2022] [Accepted: 04/04/2022] [Indexed: 05/19/2023]
Abstract
Dothistroma needle blight, caused by Dothistroma septosporum, has increased in incidence and severity over the last few decades and is now one of the most important global diseases of pines. Disease resistance breeding could be accelerated by knowledge of pathogen virulence factors and their host targets. However, this is hindered due to inefficient targeted gene disruption in D. septosporum, which is required for virulence gene characterisation. Here we report the first successful application of CRISPR/Cas9 gene editing to a Dothideomycete forest pathogen, D. septosporum. Disruption of the dothistromin pathway regulator gene AflR, with a known phenotype, was performed using nonhomologous end-joining repair with an efficiency of > 90%. Transformants with a range of disruption mutations in AflR were produced. Disruption of Ds74283, a D. septosporum gene encoding a secreted cell death elicitor, was also achieved using CRISPR/Cas9, by using a specific donor DNA repair template to aid selection where the phenotype was unknown. In this case, 100% of screened transformants were identified as disruptants. In establishing CRISPR/Cas9 as a tool for gene editing in D. septosporum, our research could fast track the functional characterisation of candidate virulence factors in D. septosporum and helps set the foundation for development of this technology in other forest pathogens.
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Affiliation(s)
- Hannah M. McCarthy
- BioProtection Aotearoa, School of Natural Sciences, Massey University, Palmerston North 4472, New Zealand; (M.T.); (R.E.B.)
- Correspondence:
| | - Mariana Tarallo
- BioProtection Aotearoa, School of Natural Sciences, Massey University, Palmerston North 4472, New Zealand; (M.T.); (R.E.B.)
| | - Carl H. Mesarich
- BioProtection Aotearoa, School of Agriculture and Environment, Massey University, Palmerston North 4472, New Zealand;
| | - Rebecca L. McDougal
- Scion, New Zealand Forest Research Institute Ltd., Rotorua 3010, New Zealand;
| | - Rosie E. Bradshaw
- BioProtection Aotearoa, School of Natural Sciences, Massey University, Palmerston North 4472, New Zealand; (M.T.); (R.E.B.)
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Fast and efficient CRISPR-mediated genome editing in Aureobasidium using Cas9 ribonucleoproteins. J Biotechnol 2022; 350:11-16. [DOI: 10.1016/j.jbiotec.2022.03.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 02/03/2022] [Accepted: 03/28/2022] [Indexed: 11/19/2022]
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Nickles G, Ludwikoski I, Bok JW, Keller NP. Comprehensive Guide to Extracting and Expressing Fungal Secondary Metabolites with Aspergillus fumigatus as a Case Study. Curr Protoc 2021; 1:e321. [PMID: 34958718 DOI: 10.1002/cpz1.321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Fungal secondary metabolites (SMs) have captured the interest of natural products researchers in academia and industry for decades. In recent years, the high rediscovery rate of previously characterized metabolites is making it increasingly difficult to uncover novel compounds. Additionally, the vast majority of fungal SMs reside in genetically intractable fungi or are silent under normal laboratory conditions in genetically tractable fungi. The fungal natural products community has broadly overcome these barriers by altering the physical growth conditions of the fungus and heterologous/homologous expression of biosynthetic gene cluster regulators or proteins. The protocols described here summarize vital methodologies needed when researching SM production in fungi. We also summarize the growth conditions, genetic backgrounds, and extraction protocols for every published SM in Aspergillus fumigatus, enabling readers to easily replicate the production of previously characterized SMs. Readers will also be equipped with the tools for developing their own strategy for expressing and extracting SMs from their given fungus or a suitable heterologous model system. © 2021 Wiley Periodicals LLC. Basic Protocol 1: Making glycerol stocks from spore suspensions Alternate Protocol 1: Creating glycerol stocks from non-sporulating filamentous fungi Basic Protocol 2: Activating spore-suspension glycerol stocks Basic Protocol 3: Extracting secondary metabolites from Aspergillus spp grown on solid medium Alternate Protocol 2: Extracting secondary metabolites from Aspergillus spp using ethyl acetate Alternate Protocol 3: High-volume metabolite extraction using ethyl acetate Alternate Protocol 4: Extracting secondary metabolites from Aspergillus spp in liquid medium Support Protocol: Creating an overlay culture Basic Protocol 4: Extracting DNA from filamentous fungi Basic Protocol 5: Creating a DNA construct with double-joint PCR Alternate Protocol 5: Creating a DNA construct with yeast recombineering Basic Protocol 6: Transformation of Aspergillus spp Basic Protocol 7: Co-culturing fungi and bacteria for extraction of secondary metabolites.
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Affiliation(s)
- Grant Nickles
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Isabelle Ludwikoski
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Jin Woo Bok
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin
| | - Nancy P Keller
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, Madison, Wisconsin.,Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin
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CRISPR-Cas9 gene editing and rapid detection of gene-edited mutants using high-resolution melting in the apple scab fungus, Venturia inaequalis. Fungal Biol 2021; 126:35-46. [PMID: 34930557 DOI: 10.1016/j.funbio.2021.10.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2021] [Revised: 09/27/2021] [Accepted: 10/07/2021] [Indexed: 11/24/2022]
Abstract
Apple scab, caused by the fungal pathogen Venturia inaequalis, is the most economically important disease of apple (Malus x domestica) worldwide. To develop durable control strategies against this disease, a better understanding of the genetic mechanisms underlying the growth, reproduction, virulence and pathogenicity of V. inaequalis is required. A major bottleneck for the genetic characterization of V. inaequalis is the inability to easily delete or disrupt genes of interest using homologous recombination. Indeed, no gene deletions or disruptions in V. inaequalis have yet been published. Using the melanin biosynthesis pathway gene trihydroxynaphthalene reductase (THN) as a target for inactivation, which has previously been shown to result in a light-brown colony phenotype when transcriptionally silenced using RNA interference, we show, for the first time, that the CRISPR-Cas9 gene editing system can be successfully applied to the apple scab fungus. More specifically, using a CRISPR-Cas9 single guide RNA (sgRNA) targeted to the THN gene, delivered by a single autonomously replicating Golden Gate-compatible plasmid, we were able to identify six of 36 stable transformants with a light-brown phenotype, indicating an ∼16.7% gene inactivation efficiency. Notably, of the six THN mutants, five had an independent mutation. As part of our pipeline, we also report a high-resolution melting (HRM) curve protocol for the rapid detection of CRISPR-Cas9 gene-edited mutants of V. inaequalis. This protocol identified a single base pair deletion mutation in a sample containing only 5% mutant genomic DNA, indicating high sensitivity for mutant screening. In establishing CRISPR-Cas9 as a tool for gene editing in V. inaequalis, we have provided a strong starting point for studies aiming to decipher gene function in this fungus. The associated HRM curve protocol will enable CRISPR-Cas9 transformants to be screened for gene inactivation in a high-throughput and low-cost manner, which will be particularly powerful in cases where the CRISPR-Cas9-mediated gene inactivation efficiency is low.
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Fan C, Zhang W, Su X, Ji W, Luo H, Zhang Y, Liu B, Yao B, Huang H, Xu X. CRISPR/Cas9-mediated genome editing directed by a 5S rRNA-tRNA Gly hybrid promoter in the thermophilic filamentous fungus Humicola insolens. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:206. [PMID: 34688310 PMCID: PMC8542335 DOI: 10.1186/s13068-021-02057-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/18/2021] [Accepted: 10/13/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Humicola insolens is a filamentous fungus with high potential of producing neutral and heat- and alkali-resistant cellulase. However, the genetic engineering tools, particularly the genome-editing tool, are scarce, hindering the study of cellulase expression regulation in this organism. RESULTS Herein, a CRISPR/Cas9 genome-editing system was established in H. insolens based on a hybrid 5S rRNA-tRNAGly promoter. This system is superior to the HDV (hepatitis delta virus) system in genome editing, allowing highly efficient single gene destruction in H. insolens with rates of deletion up to 84.1% (37/44). With this system, a putative pigment synthesis gene pks and the transcription factor xyr1 gene were disrupted with high efficiency. Moreover, the extracellular protein concentration and cellulase activity largely decreased when xyr1 was deleted, demonstrating for the first time that Xyr1 plays an important role in cellulase expression regulation. CONCLUSIONS The established CRISPR/Cas9 system is a powerful genetic operation tool for H. insolens, which will accelerate studies on the regulation mechanism of cellulase expression and engineering of H. insolens for higher cellulase production.
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Affiliation(s)
- Chao Fan
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun St., Haidian District, Beijing, 100081, China
| | - Wei Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun St., Haidian District, Beijing, 100081, China
| | - Xiaoyun Su
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, No. 2 West Yuanmingyuan Road, Haidian District, Beijing, 100193, China
| | - Wangli Ji
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun St., Haidian District, Beijing, 100081, China
| | - Huiying Luo
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, No. 2 West Yuanmingyuan Road, Haidian District, Beijing, 100193, China
| | - Yuhong Zhang
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun St., Haidian District, Beijing, 100081, China
| | - Bo Liu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun St., Haidian District, Beijing, 100081, China
| | - Bin Yao
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, No. 2 West Yuanmingyuan Road, Haidian District, Beijing, 100193, China
| | - Huoqing Huang
- Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, No. 2 West Yuanmingyuan Road, Haidian District, Beijing, 100193, China.
| | - Xinxin Xu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, No. 12 South Zhongguancun St., Haidian District, Beijing, 100081, China.
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Staerck C, Yaakoub H, Vandeputte P, Tabiasco J, Godon C, Gastebois A, Giraud S, Guillemette T, Calenda A, Delneste Y, Fleury M, Bouchara JP. The Glycosylphosphatidylinositol-Anchored Superoxide Dismutase of Scedosporium apiospermum Protects the Conidia from Oxidative Stress. J Fungi (Basel) 2021; 7:575. [PMID: 34356954 PMCID: PMC8304446 DOI: 10.3390/jof7070575] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Revised: 07/13/2021] [Accepted: 07/13/2021] [Indexed: 02/07/2023] Open
Abstract
Scedosporium species are common fungal pathogens in patients with cystic fibrosis (CF). To colonize the CF lungs, fungi must cope with the host immune response, especially the reactive oxygen species (ROS) released by phagocytic cells. To this aim, pathogens have developed various antioxidant systems, including superoxide dismutases (SODs) which constitute the first-line protection against oxidative stress. Interestingly, one of the S. apiospermum SOD-encoding genes (SODD gene) exhibits a glycosylphosphatidylinositol (GPI) anchor-binding site and encodes a conidial-specific surface SOD. In this study, a SODDΔ mutant was engineered from a non-homologous end joining-deficient strain (KU70Δ) of S. apiospermum. Compared to its parent strain, the double mutant KU70Δ/SODDΔ exhibited increased susceptibility to various oxidizing agents and triazole antifungals. In addition, the loss of SodD resulted in an increased intracellular killing of the conidia by M1 macrophages derived from human blood monocytes, suggesting the involvement of this superoxide dismutase in the evasion to the host defenses. Nevertheless, one cannot disregard an indirect role of the enzyme in the synthesis or assembly of the cell wall components since transmission electron microscopic analysis revealed a thickening of the inner cell wall layer of the conidia. Further studies are needed to confirm the role of this enzyme in the pathogenesis of Scedosporium infections, including the production of a recombinant protein and study of its protective effect against the infection in a mouse model of scedosporiosis.
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Affiliation(s)
- Cindy Staerck
- Université d’Angers, Université de Bretagne Occidentale, CHU Angers, Groupe d’Etude des Interactions Hôte-Pathogène (GEIHP, EA3142), SFR ICAT, F-49000 Angers, France; (C.S.); (H.Y.); (P.V.); (C.G.); (A.G.); (S.G.); (A.C.); (M.F.)
| | - Hajar Yaakoub
- Université d’Angers, Université de Bretagne Occidentale, CHU Angers, Groupe d’Etude des Interactions Hôte-Pathogène (GEIHP, EA3142), SFR ICAT, F-49000 Angers, France; (C.S.); (H.Y.); (P.V.); (C.G.); (A.G.); (S.G.); (A.C.); (M.F.)
| | - Patrick Vandeputte
- Université d’Angers, Université de Bretagne Occidentale, CHU Angers, Groupe d’Etude des Interactions Hôte-Pathogène (GEIHP, EA3142), SFR ICAT, F-49000 Angers, France; (C.S.); (H.Y.); (P.V.); (C.G.); (A.G.); (S.G.); (A.C.); (M.F.)
| | - Julie Tabiasco
- Université d’Angers, Université de Nantes, CHU Angers, Inserm, CRCINA, SFR ICAT, F-49000 Angers, France; (J.T.); (Y.D.)
| | - Charlotte Godon
- Université d’Angers, Université de Bretagne Occidentale, CHU Angers, Groupe d’Etude des Interactions Hôte-Pathogène (GEIHP, EA3142), SFR ICAT, F-49000 Angers, France; (C.S.); (H.Y.); (P.V.); (C.G.); (A.G.); (S.G.); (A.C.); (M.F.)
| | - Amandine Gastebois
- Université d’Angers, Université de Bretagne Occidentale, CHU Angers, Groupe d’Etude des Interactions Hôte-Pathogène (GEIHP, EA3142), SFR ICAT, F-49000 Angers, France; (C.S.); (H.Y.); (P.V.); (C.G.); (A.G.); (S.G.); (A.C.); (M.F.)
| | - Sandrine Giraud
- Université d’Angers, Université de Bretagne Occidentale, CHU Angers, Groupe d’Etude des Interactions Hôte-Pathogène (GEIHP, EA3142), SFR ICAT, F-49000 Angers, France; (C.S.); (H.Y.); (P.V.); (C.G.); (A.G.); (S.G.); (A.C.); (M.F.)
| | - Thomas Guillemette
- Université d’Angers, Institut Agro, INRAE, IRHS, SFR QUASAV, F-49000 Angers, France;
| | - Alphonse Calenda
- Université d’Angers, Université de Bretagne Occidentale, CHU Angers, Groupe d’Etude des Interactions Hôte-Pathogène (GEIHP, EA3142), SFR ICAT, F-49000 Angers, France; (C.S.); (H.Y.); (P.V.); (C.G.); (A.G.); (S.G.); (A.C.); (M.F.)
| | - Yves Delneste
- Université d’Angers, Université de Nantes, CHU Angers, Inserm, CRCINA, SFR ICAT, F-49000 Angers, France; (J.T.); (Y.D.)
| | - Maxime Fleury
- Université d’Angers, Université de Bretagne Occidentale, CHU Angers, Groupe d’Etude des Interactions Hôte-Pathogène (GEIHP, EA3142), SFR ICAT, F-49000 Angers, France; (C.S.); (H.Y.); (P.V.); (C.G.); (A.G.); (S.G.); (A.C.); (M.F.)
| | - Jean-Philippe Bouchara
- Université d’Angers, Université de Bretagne Occidentale, CHU Angers, Groupe d’Etude des Interactions Hôte-Pathogène (GEIHP, EA3142), SFR ICAT, F-49000 Angers, France; (C.S.); (H.Y.); (P.V.); (C.G.); (A.G.); (S.G.); (A.C.); (M.F.)
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Sarmiento-Villamil JL, de Oliveira TC, Naruzawa ES, Bernier L. An Efficient Strategy for Obtaining Mutants by Targeted Gene Deletion in Ophiostoma novo-ulmi. Front Microbiol 2021; 12:699783. [PMID: 34335533 PMCID: PMC8317267 DOI: 10.3389/fmicb.2021.699783] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Accepted: 06/21/2021] [Indexed: 11/15/2022] Open
Abstract
The dimorphic fungus Ophiostoma novo-ulmi is the highly aggressive pathogen responsible for the current, highly destructive, pandemic of Dutch elm disease (DED). Genome and transcriptome analyses of this pathogen previously revealed that a large set of genes expressed during dimorphic transition were also potentially related to plant infection processes, which seem to be regulated by molecular mechanisms different from those described in other dimorphic pathogens. Then, O. novo-ulmi can be used as a representative species to study the lifestyle of dimorphic pathogenic fungi that are not shared by the "model species" Candida albicans and Ustilago maydis. In order to gain better knowledge of molecular aspects underlying infection process and symptom induction by dimorphic fungi that cause vascular wilt disease, we developed a high-throughput gene deletion protocol for O. novo-ulmi. The protocol is based on transforming a Δmus52 O. novo-ulmi mutant impaired for non-homologous end joining (NHEJ) as the recipient strain, and transforming this strain with the latest version of OSCAR plasmids. The latter are used for generating deletion constructs containing the toxin-coding Herpes simplex virus thymidine kinase (HSVtk) gene which prevents ectopic integration of the T-DNA in Ophiostoma DNA. The frequency of gene deletion by homologous recombination (HR) at the ade1 locus associated with purine nucleotide biosynthesis was up to 77.8% in the Δmus52 mutant compared to 2% in the wild-type (WT). To validate the high efficiency of our deletion gene methodology we deleted ade7, which also belongs to the purine nucleotide pathway, as well as bct2, ogf1, and opf2 which encode fungal binuclear transcription factors (TFs). The frequency of gene replacement by HR for these genes reached up to 94%. We expect that our methodology combining the use of NHEJ deficient strains and OSCAR plasmids will function with similar high efficiencies for other O. novo-ulmi genes and other filamentous fungi.
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Affiliation(s)
- Jorge Luis Sarmiento-Villamil
- Centre d’Étude de la Forêt (CEF) and Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Quebec City, QC, Canada
| | - Thais Campos de Oliveira
- Centre d’Étude de la Forêt (CEF) and Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Quebec City, QC, Canada
| | - Erika Sayuri Naruzawa
- Centre d’Étude de la Forêt (CEF) and Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Quebec City, QC, Canada
- Collège Communautaire du Nouveau-Brunswick, Réseau CCNB-INNOV, Grand Falls, NB, Canada
| | - Louis Bernier
- Centre d’Étude de la Forêt (CEF) and Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Quebec City, QC, Canada
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23
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Transcriptional Responses of Sclerotinia sclerotiorum to the Infection by SsHADV-1. J Fungi (Basel) 2021; 7:jof7070493. [PMID: 34206246 PMCID: PMC8303302 DOI: 10.3390/jof7070493] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Revised: 06/14/2021] [Accepted: 06/16/2021] [Indexed: 12/13/2022] Open
Abstract
The infection by a single-stranded DNA virus, Sclerotinia sclerotiorum hypovirulence-associated DNA virus 1 (SsHADV-1), causes hypovirulence, a reduced growth rate, and other colony morphological changes in its host Sclerotinia sclerotiorum strain DT-8. However, the mechanisms of the decline are still unclear. Using digital RNA sequencing, a transcriptome analysis was conducted to elucidate the phenotype-related genes with expression changes in response to SsHADV-1 infection. A total of 3110 S. sclerotiorum differentially expressed genes (DEGs) were detected during SsHADV-1 infection, 1741 of which were up-regulated, and 1369 were down-regulated. The identified DEGs were involved in several important pathways. DNA replication, DNA damage response, carbohydrate and lipid metabolism, ribosomal assembly, and translation were the affected categories in S. sclerotiorum upon SsHADV-1 infection. Moreover, the infection of SsHADV-1 also suppressed the expression of antiviral RNA silencing and virulence factor genes. These results provide further detailed insights into the effects of SsHADV-1 infection on the whole genome transcription in S. sclerotiorum.
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24
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Seekles SJ, Teunisse PPP, Punt M, van den Brule T, Dijksterhuis J, Houbraken J, Wösten HAB, Ram AFJ. Preservation stress resistance of melanin deficient conidia from Paecilomyces variotii and Penicillium roqueforti mutants generated via CRISPR/Cas9 genome editing. Fungal Biol Biotechnol 2021; 8:4. [PMID: 33795004 PMCID: PMC8017634 DOI: 10.1186/s40694-021-00111-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 03/11/2021] [Indexed: 01/25/2023] Open
Abstract
Background The filamentous fungi Paecilomyces variotii and Penicillium roqueforti are prevalent food spoilers and are of interest as potential future cell factories. A functional CRISPR/Cas9 genome editing system would be beneficial for biotechnological advances as well as future (genetic) research in P. variotii and P. roqueforti. Results Here we describe the successful implementation of an efficient AMA1-based CRISPR/Cas9 genome editing system developed for Aspergillus niger in P. variotii and P. roqueforti in order to create melanin deficient strains. Additionally, kusA− mutant strains with a disrupted non-homologous end-joining repair mechanism were created to further optimize and facilitate efficient genome editing in these species. The effect of melanin on the resistance of conidia against the food preservation stressors heat and UV-C radiation was assessed by comparing wild-type and melanin deficient mutant conidia. Conclusions Our findings show the successful use of CRISPR/Cas9 genome editing and its high efficiency in P. variotii and P. roqueforti in both wild-type strains as well as kusA− mutant background strains. Additionally, we observed that melanin deficient conidia of three food spoiling fungi were not altered in their heat resistance. However, melanin deficient conidia had increased sensitivity towards UV-C radiation. Supplementary Information The online version contains supplementary material available at 10.1186/s40694-021-00111-w.
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Affiliation(s)
- Sjoerd J Seekles
- TIFN, Agro Business Park 82, 6708 PW, Wageningen, The Netherlands.,Department Molecular Microbiology and Biotechnology, Institute of Biology, Leiden University, Sylviusweg 72, 2333BE, Leiden, The Netherlands
| | - Pepijn P P Teunisse
- TIFN, Agro Business Park 82, 6708 PW, Wageningen, The Netherlands.,Department Molecular Microbiology and Biotechnology, Institute of Biology, Leiden University, Sylviusweg 72, 2333BE, Leiden, The Netherlands
| | - Maarten Punt
- TIFN, Agro Business Park 82, 6708 PW, Wageningen, The Netherlands.,Microbiology, Department of Biology, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Tom van den Brule
- TIFN, Agro Business Park 82, 6708 PW, Wageningen, The Netherlands.,Applied & Industrial Mycology, Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, 3584 CT, Utrecht, the Netherlands
| | - Jan Dijksterhuis
- TIFN, Agro Business Park 82, 6708 PW, Wageningen, The Netherlands.,Applied & Industrial Mycology, Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, 3584 CT, Utrecht, the Netherlands
| | - Jos Houbraken
- TIFN, Agro Business Park 82, 6708 PW, Wageningen, The Netherlands.,Applied & Industrial Mycology, Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, 3584 CT, Utrecht, the Netherlands
| | - Han A B Wösten
- TIFN, Agro Business Park 82, 6708 PW, Wageningen, The Netherlands.,Microbiology, Department of Biology, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Arthur F J Ram
- TIFN, Agro Business Park 82, 6708 PW, Wageningen, The Netherlands. .,Department Molecular Microbiology and Biotechnology, Institute of Biology, Leiden University, Sylviusweg 72, 2333BE, Leiden, The Netherlands.
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25
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Resistance Marker- and Gene Gun-Mediated Transformation of Trichoderma reesei. Methods Mol Biol 2021. [PMID: 33165778 DOI: 10.1007/978-1-0716-1048-0_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/26/2023]
Abstract
Transformation enables the transfer of DNA into fungal cells for subsequent integration into the genome. Due to its versatility in industrial application, transformation is of utmost importance in Trichoderma reesei and hence continuously optimized. As one of the most crucial obstacles in fungal transformation efforts, removal of the cell wall is required to efficiently target genome modification cassettes to the genome. Here we describe resistance marker-mediated gene gun (biolistic) transformation of fungal spores of T. reesei as an alternative to protoplast transformation.
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26
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Enzymology and biosynthesis of the orsellinic acid derived medicinal meroterpenoids. Curr Opin Biotechnol 2020; 69:52-59. [PMID: 33383296 DOI: 10.1016/j.copbio.2020.11.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 11/02/2020] [Accepted: 11/30/2020] [Indexed: 01/07/2023]
Abstract
The advent of synthetic biology has yielded fruitful studies on orsellinic acid-derived meroterpenoids, which reportedly possess important biological activities. Genomics and transcriptomics have significantly accelerated the discovery of the biosynthetic genes for orsellinic acid-derived fungal and plant meroterpenoids. Subsequently, a well-developed heterologous host provides a convenient platform to generate a supply of useful natural products. Furthermore, in vitro reconstitution and genome editing tools have been increasingly employed as efficient means to fully understand the enzyme reaction mechanisms. With the knowledge of the biosynthetic machinery, combinatorial and engineered biosyntheses have yielded novel molecules with improved bioactivities. These studies will lay the foundation for the production of meroterpenoids with novel medicinal properties.
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An advanced genetic toolkit for exploring the biology of the rock-inhabiting black fungus Knufia petricola. Sci Rep 2020; 10:22021. [PMID: 33328531 PMCID: PMC7745021 DOI: 10.1038/s41598-020-79120-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 12/03/2020] [Indexed: 01/09/2023] Open
Abstract
Microcolonial black fungi are a group of ascomycetes that exhibit high stress tolerance, yeast-like growth and constitutive melanin formation. They dominate a range of hostile natural and man-made environments, from desert rocks and salterns to dishwashers, roofs and solar panels. Due to their slow growth and a lack of genetic tools, the underlying mechanisms of black fungi’s phenotypic traits have remained largely unexplored. We chose to address this gap by genetically engineering the rock-inhabiting fungus Knufia petricola (Eurotiomycetes, Chaetothyriales), a species that exhibits all characteristics of black fungi. A cell biological approach was taken by generating K. petricola strains expressing green or red fluorescent protein variants. By applying: (1) traditional gene replacement; (2) gene editing and replacement via plasmid-based or ribonucleoprotein (RNP)-based CRISPR/Cas9, and (3) silencing by RNA interference (RNAi), we constructed mutants in the pathways leading to melanin, carotenoids, uracil and adenine. Stable single and double mutants were generated with homologous recombination (HR) rates up to 100%. Efficient, partially cloning-free strategies to mutate multiple genes with or without resistance cassettes were developed. This state-of-the-art genetic toolkit, together with the annotated genome sequence of strain A95, firmly established K. petricola as a model for exploring microcolonial black fungi.
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28
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Swilaiman SS, O’Gorman CM, Du W, Sugui JA, Del Buono J, Brock M, Kwon-Chung KJ, Szakacs G, Dyer PS. Global Sexual Fertility in the Opportunistic Pathogen Aspergillus fumigatus and Identification of New Supermater Strains. J Fungi (Basel) 2020; 6:E258. [PMID: 33143051 PMCID: PMC7712211 DOI: 10.3390/jof6040258] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 10/26/2020] [Accepted: 10/27/2020] [Indexed: 12/26/2022] Open
Abstract
A sexual cycle in Aspergillus fumigatus was first described in 2009 with isolates from Dublin, Ireland. However, the extent to which worldwide isolates can undergo sexual reproduction has remained unclear. In this study a global collection of 131 isolates was established with a near 1:1 ratio of mating types. All isolates were crossed to MAT1-1 or MAT1-2 Irish strains, and a subset of isolates from different continents were crossed together. Ninety seven percent of isolates were found to produce cleistothecia with at least one mating partner, showing that sexual fertility is not limited to the Irish population but is a characteristic of global A. fumigatus. However, large variation was seen in numbers of cleistothecia produced per cross, suggesting differences in the possibility for genetic exchange between strains in nature. The majority of crosses produced ascospores with >50% germination rates, but with wide variation evident. A high temperature heat shock was required to induce ascospore germination. Finally, a new set of highly fertile MAT1-1 and MAT1-2 supermater strains were identified and pyrimidine auxotrophs generated for community use. Results provide insights into the potential for the A. fumigatus sexual cycle to generate genetic variation and allow gene flow of medically important traits.
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Affiliation(s)
- Sameira S. Swilaiman
- School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK; (S.S.S.); (C.M.O.); (W.D.); (J.D.B.); (M.B.)
| | - Céline M. O’Gorman
- School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK; (S.S.S.); (C.M.O.); (W.D.); (J.D.B.); (M.B.)
| | - Wenyue Du
- School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK; (S.S.S.); (C.M.O.); (W.D.); (J.D.B.); (M.B.)
| | - Janyce A. Sugui
- Molecular Microbiology Section, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20825, USA; (J.A.S.); (K.J.K.-C.)
| | - Joanne Del Buono
- School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK; (S.S.S.); (C.M.O.); (W.D.); (J.D.B.); (M.B.)
| | - Matthias Brock
- School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK; (S.S.S.); (C.M.O.); (W.D.); (J.D.B.); (M.B.)
| | - Kyung J. Kwon-Chung
- Molecular Microbiology Section, Laboratory of Clinical Immunology and Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20825, USA; (J.A.S.); (K.J.K.-C.)
| | - George Szakacs
- Department of Applied Biotechnology and Food Science, Budapest University of Technology and Economics, Szent Gellert ter 4, 1111 Budapest, Hungary;
| | - Paul S. Dyer
- School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK; (S.S.S.); (C.M.O.); (W.D.); (J.D.B.); (M.B.)
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Le Govic Y, Havlíček V, Capilla J, Luptáková D, Dumas D, Papon N, Le Gal S, Bouchara JP, Vandeputte P. Synthesis of the Hydroxamate Siderophore N α-Methylcoprogen B in Scedosporium apiospermum Is Mediated by sidD Ortholog and Is Required for Virulence. Front Cell Infect Microbiol 2020; 10:587909. [PMID: 33194829 PMCID: PMC7655970 DOI: 10.3389/fcimb.2020.587909] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 10/08/2020] [Indexed: 02/04/2023] Open
Abstract
Scedosporium species rank second among the filamentous fungi capable to colonize chronically the respiratory tract of patients with cystic fibrosis (CF). Nevertheless, there is little information on the mechanisms underpinning their virulence. Iron acquisition is critical for the growth and pathogenesis of many bacterial and fungal genera that chronically inhabit the CF lungs. In a previous study, we showed the presence in the genome of Scedosporium apiospermum of several genes relevant for iron uptake, notably SAPIO_CDS2806, an ortholog of sidD, which drives the synthesis of the extracellular hydroxamate-type siderophore fusarinine C (FsC) and its derivative triacetylfusarinine C (TAFC) in Aspergillus fumigatus. Here, we demonstrate that Scedosporium apiospermum sidD gene is required for production of an excreted siderophore, namely, Nα-methylcoprogen B, which also belongs to the hydroxamate family. Blockage of the synthesis of Nα-methylcoprogen B by disruption of the sidD gene resulted in the lack of fungal growth under iron limiting conditions. Still, growth of ΔsidD mutants could be restored by supplementation of the culture medium with a culture filtrate from the parent strain, but not from the mutants. Furthermore, the use of xenosiderophores as the sole source of iron revealed that S. apiospermum can acquire the iron using the hydroxamate siderophores ferrichrome or ferrioxamine, i.e., independently of Nα-methylcoprogen B production. Conversely, Nα-methylcoprogen B is mandatory for iron acquisition from pyoverdine, a mixed catecholate-hydroxamate siderophore. Finally, the deletion of sidD resulted in the loss of virulence in a murine model of scedosporiosis. Our findings demonstrate that S. apiospermum sidD gene drives the synthesis of a unique extracellular, hydroxamate-type iron chelator, which is essential for fungal growth and virulence. This compound scavenges iron from pyoverdine, which might explain why S. apiospermum and Pseudomonas aeruginosa are rarely found simultaneously in the CF lungs.
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Affiliation(s)
- Yohann Le Govic
- Groupe d'Etude des Interactions Hôte-Pathogène (GEIHP, EA 3142), SFR ICAT 4208, Université Angers, Université Brest, Angers, France.,Laboratoire de Parasitologie-Mycologie, Centre Hospitalier Universitaire, Angers, France
| | - Vladimir Havlíček
- Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
| | - Javier Capilla
- Unitat de Microbiologia, Facultat de Medicina i Ciències de la Salut, Universitat Rovira i Virgili and Institut d'Investigació Sanitària Pere Virgili (IISPV), Reus, Spain
| | - Dominika Luptáková
- Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
| | - Dayana Dumas
- Unitat de Microbiologia, Facultat de Medicina i Ciències de la Salut, Universitat Rovira i Virgili and Institut d'Investigació Sanitària Pere Virgili (IISPV), Reus, Spain
| | - Nicolas Papon
- Groupe d'Etude des Interactions Hôte-Pathogène (GEIHP, EA 3142), SFR ICAT 4208, Université Angers, Université Brest, Angers, France
| | - Solène Le Gal
- Groupe d'Etude des Interactions Hôte-Pathogène (GEIHP, EA 3142), SFR ICAT 4208, Université Angers, Université Brest, Angers, France.,Laboratoire de Parasitologie-Mycologie, Centre Hospitalier Universitaire, Brest, France
| | - Jean-Philippe Bouchara
- Groupe d'Etude des Interactions Hôte-Pathogène (GEIHP, EA 3142), SFR ICAT 4208, Université Angers, Université Brest, Angers, France.,Laboratoire de Parasitologie-Mycologie, Centre Hospitalier Universitaire, Angers, France
| | - Patrick Vandeputte
- Groupe d'Etude des Interactions Hôte-Pathogène (GEIHP, EA 3142), SFR ICAT 4208, Université Angers, Université Brest, Angers, France.,Laboratoire de Parasitologie-Mycologie, Centre Hospitalier Universitaire, Angers, France
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30
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Kondrateva E, Demchenko A, Lavrov A, Smirnikhina S. An overview of currently available molecular Cas-tools for precise genome modification. Gene 2020; 769:145225. [PMID: 33059029 DOI: 10.1016/j.gene.2020.145225] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 10/06/2020] [Accepted: 10/07/2020] [Indexed: 12/17/2022]
Abstract
CRISPR-Cas system was first mentioned in 1987, and over the years have been studied so active that now it becomes the state-of-the-art tool for genome editing. Its working principle is based on Cas nuclease ability to bind short RNA, which targets it to complementary DNA or RNA sequence for highly precise cleavage. This alone or together with donor DNA allows to modify targeted sequence in different ways. Considering the many limitations of using native CRISPR-Cas systems, scientists around the world are working on creating modified variants to improve their specificity and efficiency in different objects. In addition, the use of the Cas effectors' targeting function in complex systems with other proteins is a promising work direction, as a result of which new tools are created with features such as single base editing, editing DNA without break and donor DNA, activation and repression of transcription, epigenetic regulation, modifying of different repair pathways involvement etc. In this review, we decided to consider in detail exactly this issue of variants of Cas effectors, their modifications and fusion molecules, which improve DNA-targeting and expand the scope of Cas effectors.
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Affiliation(s)
- Ekaterina Kondrateva
- Research Centre for Medical Genetics, Laboratory of Genome Editing, Moscow 115522, Russia.
| | - Anna Demchenko
- Research Centre for Medical Genetics, Laboratory of Genome Editing, Moscow 115522, Russia
| | - Alexander Lavrov
- Research Centre for Medical Genetics, Laboratory of Genome Editing, Moscow 115522, Russia
| | - Svetlana Smirnikhina
- Research Centre for Medical Genetics, Laboratory of Genome Editing, Moscow 115522, Russia
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31
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Contributions of Spore Secondary Metabolites to UV-C Protection and Virulence Vary in Different Aspergillus fumigatus Strains. mBio 2020; 11:mBio.03415-19. [PMID: 32071276 PMCID: PMC7029147 DOI: 10.1128/mbio.03415-19] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Fungal spores contain secondary metabolites that can protect them from a multitude of abiotic and biotic stresses. Conidia (asexual spores) of the human pathogen Aspergillus fumigatus synthesize several metabolites, including melanin, which has been reported to be important for virulence in this species and to be protective against UV radiation in other fungi. Here, we investigate the role of melanin in diverse isolates of A. fumigatus and find variability in its ability to protect spores from UV-C radiation or impact virulence in a zebrafish model of invasive aspergillosis in two clinical strains and one ISS strain. Further, we assess the role of other spore metabolites in a clinical strain of A. fumigatus and identify fumiquinazoline as an additional UV-C-protective molecule but not a virulence determinant. The results show differential roles of secondary metabolites in spore protection dependent on the environmental stress and strain of A. fumigatus. As protection from elevated levels of radiation is of paramount importance for future human outer space explorations, the discovery of small molecules with radiation-protective potential may result in developing novel safety measures for astronauts. Fungi are versatile organisms which thrive in hostile environments, including the International Space Station (ISS). Several isolates of the human pathogen Aspergillus fumigatus have been found contaminating the ISS, an environment with increased exposure to UV radiation. Secondary metabolites (SMs) in spores, such as melanins, have been shown to protect spores from UV radiation in other fungi. To test the hypothesis that melanin and other known spore SMs provide UV protection to A. fumigatus isolates, we subjected SM spore mutants to UV-C radiation. We found that 1,8-dihydroxynaphthalene (DHN)-melanin mutants of two clinical A. fumigatus strains (Af293 and CEA17) but not an ISS-isolated strain (IF1SW-F4) were more sensitive to UV-C than their respective wild-type (WT) strains. Because DHN-melanin has been shown to shield A. fumigatus from the host immune system, we examined all DHN mutants for virulence in the zebrafish model of invasive aspergillosis. Following recent studies highlighting the pathogenic variability of different A. fumigatus isolates, we found DHN-melanin to be a virulence factor in CEA17 and IF1SW-F4 but not Af293. Three additional spore metabolites were examined in Af293, where fumiquinazoline also showed UV-C-protective properties, but two other spore metabolites, monomethylsulochrin and fumigaclavine, provided no UV-C-protective properties. Virulence tests of these three SM spore mutants indicated a slight increase in virulence of the monomethylsulochrin deletion strain. Taken together, this work suggests differential roles of specific spore metabolites across Aspergillus isolates and by types of environmental stress.
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32
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Villena GK, Kitazono AA, Hernández-Macedo M L. Bioengineering Fungi and Yeast for the Production of Enzymes, Metabolites, and Value-Added Compounds. Fungal Biol 2020. [DOI: 10.1007/978-3-030-41870-0_9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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33
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Qiao YM, Yu RL, Zhu P. Advances in targeting and heterologous expression of genes involved in the synthesis of fungal secondary metabolites. RSC Adv 2019; 9:35124-35134. [PMID: 35530690 PMCID: PMC9074735 DOI: 10.1039/c9ra06908a] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 10/18/2019] [Indexed: 01/11/2023] Open
Abstract
The revolutionary discovery of penicillin only marks the start of our exploration for valuable fungal natural products. Advanced genome sequencing technologies have translated the fungal genome into a huge reservoir of "recipes" - biosynthetic gene clusters (BGCs) - for biosynthesis. Studying complex fungal genetics demands specific gene manipulation strategies. This review summarizes the current progress in efficient gene targeting in fungal cells and heterologous expression systems for expressing fungal BGCs of fungal secondary metabolites.
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Affiliation(s)
- Yun-Ming Qiao
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, NHC Key Laboratory of Biosynthesis of Natural Products, CAMS Key Laboratory of Enzyme and Biocatalysis of Natural Drugs, Institute of Materia Medica, Chinese Academy of Medical Sciences, Peking Union Medical College Beijing 100050 China +86-10-63017757 +86-10-63165197
| | - Rui-Lin Yu
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, NHC Key Laboratory of Biosynthesis of Natural Products, CAMS Key Laboratory of Enzyme and Biocatalysis of Natural Drugs, Institute of Materia Medica, Chinese Academy of Medical Sciences, Peking Union Medical College Beijing 100050 China +86-10-63017757 +86-10-63165197
| | - Ping Zhu
- State Key Laboratory of Bioactive Substance and Function of Natural Medicines, NHC Key Laboratory of Biosynthesis of Natural Products, CAMS Key Laboratory of Enzyme and Biocatalysis of Natural Drugs, Institute of Materia Medica, Chinese Academy of Medical Sciences, Peking Union Medical College Beijing 100050 China +86-10-63017757 +86-10-63165197
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34
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Mahmoudjanlou Y, Hoff B, Kück U. Construction of a Codon-Adapted Nourseotricin-Resistance Marker Gene for Efficient Targeted Gene Deletion in the Mycophenolic Acid Producer Penicillium brevicompactum. J Fungi (Basel) 2019; 5:E96. [PMID: 31658687 PMCID: PMC6958462 DOI: 10.3390/jof5040096] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 10/01/2019] [Accepted: 10/06/2019] [Indexed: 11/16/2022] Open
Abstract
Penicillium brevicompactum is a filamentous ascomycete used in the pharmaceutical industry to produce mycophenolic acid, an immunosuppressant agent. To extend options for genetic engineering of this fungus, we have tested two resistance markers that have not previously been applied to P. brevicompactum. Although a generally available phleomycin resistance marker (ble) was successfully used in DNA-mediated transformation experiments, we were not able to use a commonly applicable nourseothricin resistance cassette (nat1). To circumvent this failure, we constructed a new nat gene, considering the codon bias for P. brevicompactum. We then used this modified nat gene in subsequent transformation experiments for the targeted disruption of two nuclear genes, MAT1-2-1 and flbA. For MAT1-2-1, we obtained deletion strains with a frequency of about 10%. In the case of flbA, the frequency was about 4%, and this disruption strain also showed reduced conidiospore formation. To confirm the deletion, we used ble to reintroduce the wild-type genes. This step restored the wild-type phenotype in the flbA deletion strain, which had a sporulation defect. The successful transformation system described here substantially extends options for genetically manipulating the biotechnologically relevant fungus P. brevicompactum.
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Affiliation(s)
| | - Birgit Hoff
- Allgemeine & Molekulare Botanik, Ruhr-Universität Bochum, 44780 Bochum, Germany.
| | - Ulrich Kück
- Allgemeine & Molekulare Botanik, Ruhr-Universität Bochum, 44780 Bochum, Germany.
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Kjærbølling I, Mortensen UH, Vesth T, Andersen MR. Strategies to establish the link between biosynthetic gene clusters and secondary metabolites. Fungal Genet Biol 2019; 130:107-121. [DOI: 10.1016/j.fgb.2019.06.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 05/26/2019] [Accepted: 06/02/2019] [Indexed: 01/01/2023]
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Ito Y, Watanabe T, Aikawa S, Nishi T, Nishiyama T, Nakamura Y, Hasunuma T, Okubo Y, Ishii J, Kondo A. Deletion of DNA ligase IV homolog confers higher gene targeting efficiency on homologous recombination in Komagataella phaffii. FEMS Yeast Res 2019; 18:5054040. [PMID: 30010892 DOI: 10.1093/femsyr/foy074] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Accepted: 07/12/2018] [Indexed: 01/24/2023] Open
Abstract
The non-conventional yeast Komagataella phaffii, formerly Pichia pastoris, is a popular host for recombinant protein production. The relatively lower gene targeting efficiency observed in this species occurs due to high levels of non-homologous recombination activity. In the current study, we explored the function of the K. phaffii homolog of DNA ligase IV (Dnl4p) by creating a DNL4-disrupted strain. To assess the roles of non-homologous end joining (NHEJ)-related proteins in this species, strains deleted for either or both genes encoding Dnl4p or the telomeric Ku complex subunit (Ku70p) were generated. These deletions were constructed by either of two distinct marker-recycling methods (yielding either a seamless gene deletion or a Cre-loxP-mediated gene deletion). The resulting dnl4- and/or ku70-deleted K. phaffii strains were used to evaluate gene targeting efficiency in gene knock-out and gene knock-in experiments. The Dnl4p-defective strain showed improved gene targeting efficiency for homologous recombination compared to the wild-type and Ku70p-deffective strains. The dnl4 ku70 double knock-out strain exhibited a further improvement in gene targeting efficiency. Thus, the K. phaffii dnl4 and dnl4 ku70 deletion strains are expected to serve as useful platforms for functional analysis and strain development in this species.
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Affiliation(s)
- Yoichiro Ito
- Engineering Biology Research Center, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
| | - Toru Watanabe
- Biotechnology Research Laboratories, Kaneka Corporation, 1-8 Miyamae-cho, Takasago-cho, Takasago, Hyogo 676-8688, Japan
| | - Shimpei Aikawa
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
| | - Teruyuki Nishi
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
- Biotechnology Research Laboratories, Kaneka Corporation, 1-8 Miyamae-cho, Takasago-cho, Takasago, Hyogo 676-8688, Japan
| | - Tozo Nishiyama
- Biotechnology Research Laboratories, Kaneka Corporation, 1-8 Miyamae-cho, Takasago-cho, Takasago, Hyogo 676-8688, Japan
| | - Yasuyuki Nakamura
- Engineering Biology Research Center, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
| | - Tomohisa Hasunuma
- Engineering Biology Research Center, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
| | - Yuji Okubo
- Biotechnology Research Laboratories, Kaneka Corporation, 1-8 Miyamae-cho, Takasago-cho, Takasago, Hyogo 676-8688, Japan
| | - Jun Ishii
- Engineering Biology Research Center, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
| | - Akihiko Kondo
- Engineering Biology Research Center, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
- Department of Chemical Science and Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
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Schuster M, Kahmann R. CRISPR-Cas9 genome editing approaches in filamentous fungi and oomycetes. Fungal Genet Biol 2019; 130:43-53. [PMID: 31048007 DOI: 10.1016/j.fgb.2019.04.016] [Citation(s) in RCA: 91] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 04/27/2019] [Accepted: 04/28/2019] [Indexed: 12/26/2022]
Abstract
Due to their biotechnological relevance as well as their importance as disease agents, filamentous fungi and oomycetes have been prime candidates for genetic selection and in vitro manipulation for decades. With the advent of new genome editing technologies such manipulations have reached a new level of speed and sophistication. The CRISPR-Cas9 genome editing technology in particular has revolutionized the ways how desired mutations can be introduced. To date, the CRISPR-Cas9 genome editing system has been established in more than 40 different species of filamentous fungi and oomycetes. In this review we describe the various approaches taken to assure expression of the components necessary for editing and describe the varying strategies used to achieve gene disruptions, gene replacements and precise editing. We discuss potential problems faced when establishing the system, propose ways to circumvent them and suggest future approaches not yet realized in filamentous fungi or oomycetes.
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Affiliation(s)
- Mariana Schuster
- Max Planck Institute for Terrestrial Microbiology, Dept. Organismic Interactions, 35043 Marburg, Germany.
| | - Regine Kahmann
- Max Planck Institute for Terrestrial Microbiology, Dept. Organismic Interactions, 35043 Marburg, Germany.
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Araki Y, Awakawa T, Matsuzaki M, Cho R, Matsuda Y, Hoshino S, Shinohara Y, Yamamoto M, Kido Y, Inaoka DK, Nagamune K, Ito K, Abe I, Kita K. Complete biosynthetic pathways of ascofuranone and ascochlorin in Acremonium egyptiacum. Proc Natl Acad Sci U S A 2019; 116:8269-8274. [PMID: 30952781 PMCID: PMC6486709 DOI: 10.1073/pnas.1819254116] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Ascofuranone (AF) and ascochlorin (AC) are meroterpenoids produced by various filamentous fungi, including Acremonium egyptiacum (synonym: Acremonium sclerotigenum), and exhibit diverse physiological activities. In particular, AF is a promising drug candidate against African trypanosomiasis and a potential anticancer lead compound. These compounds are supposedly biosynthesized through farnesylation of orsellinic acid, but the details have not been established. In this study, we present all of the reactions and responsible genes for AF and AC biosyntheses in A. egyptiacum, identified by heterologous expression, in vitro reconstruction, and gene deletion experiments with the aid of a genome-wide differential expression analysis. Both pathways share the common precursor, ilicicolin A epoxide, which is processed by the membrane-bound terpene cyclase (TPC) AscF in AC biosynthesis. AF biosynthesis branches from the precursor by hydroxylation at C-16 by the P450 monooxygenase AscH, followed by cyclization by a membrane-bound TPC AscI. All genes required for AC biosynthesis (ascABCDEFG) and a transcriptional factor (ascR) form a functional gene cluster, whereas those involved in the late steps of AF biosynthesis (ascHIJ) are present in another distantly located cluster. AF is therefore a rare example of fungal secondary metabolites requiring multilocus biosynthetic clusters, which are likely to be controlled by the single regulator, AscR. Finally, we achieved the selective production of AF in A. egyptiacum by genetically blocking the AC biosynthetic pathway; further manipulation of the strain will lead to the cost-effective mass production required for the clinical use of AF.
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Affiliation(s)
- Yasuko Araki
- Research and Development Division, Kikkoman Corporation, Noda City, Chiba 278-0037, Japan
| | - Takayoshi Awakawa
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo 113-8657, Japan
| | - Motomichi Matsuzaki
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan;
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki City, Nagasaki 852-8523, Japan
- Department of Parasitology, National Institute of Infectious Diseases, Tokyo 162-8640, Japan
| | - Rihe Cho
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Yudai Matsuda
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Shotaro Hoshino
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan
| | - Yasutomo Shinohara
- Research and Development Division, Kikkoman Corporation, Noda City, Chiba 278-0037, Japan
| | - Masaichi Yamamoto
- Institute of Mitochondrial Science Company, Ltd., Tokyo 176-0025, Japan
| | - Yasutoshi Kido
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
- Institute of Mitochondrial Science Company, Ltd., Tokyo 176-0025, Japan
- Department of Parasitology, Graduate School of Medicine, Osaka City University, Osaka 545-8585, Japan
- Research Center for Infectious Disease Sciences, Graduate School of Medicine, Osaka City University, Osaka 545-8585, Japan
| | - Daniel Ken Inaoka
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki City, Nagasaki 852-8523, Japan
- Department of Host-Defense Biochemistry, Institute of Tropical Medicine, Nagasaki University, Nagasaki 852-8523, Japan
| | - Kisaburo Nagamune
- Department of Parasitology, National Institute of Infectious Diseases, Tokyo 162-8640, Japan
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
| | - Kotaro Ito
- Research and Development Division, Kikkoman Corporation, Noda City, Chiba 278-0037, Japan
| | - Ikuro Abe
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo 113-0033, Japan;
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo 113-8657, Japan
| | - Kiyoshi Kita
- Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki City, Nagasaki 852-8523, Japan
- Department of Host-Defense Biochemistry, Institute of Tropical Medicine, Nagasaki University, Nagasaki 852-8523, Japan
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Kunitake E, Tanaka T, Ueda H, Endo A, Yarimizu T, Katoh E, Kitamoto H. CRISPR/Cas9-mediated gene replacement in the basidiomycetous yeast Pseudozyma antarctica. Fungal Genet Biol 2019; 130:82-90. [PMID: 31026589 DOI: 10.1016/j.fgb.2019.04.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 03/23/2019] [Accepted: 04/20/2019] [Indexed: 11/15/2022]
Abstract
The basidiomycetous yeast, Pseudozyma antarctica, has the ability to express industrially beneficial biodegradable plastic-degrading enzyme (PaE) and glycolipids. In this study, we developed a highly efficient gene-targeting method in P. antarctica using a CRISPR/Cas9 gene-editing approach. Transformation of protoplast cells was achieved by incubation with a ribonucleoprotein (RNP) complex prepared by mixing the Cas9 protein with a single-guide RNA together with donor DNA (dDNA) containing a selectable marker in vitro. The PaE gene was selected as the targeted locus for gene disruption and gene-disrupted colonies were readily detected by their ability to degrade polybutylene succinate-co-adipate on solid media. The accuracy of the gene conversion event was confirmed by colony PCR. An increase in the RNP mix increased both transformation and gene disruption efficiencies. Examining the effect of the homology arm length of the dDNA revealed that dDNA with homology arms longer than 0.1 kb induced efficient homologous recombination in our system. Furthermore, this system was successful in another targeted locus, PaADE2. Following the creation of RNP-induced double-strand break of the chromosomal DNA, dDNA could be inserted into the target locus even in the absence of homology arms.
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Affiliation(s)
- Emi Kunitake
- National Agriculture and Food Research Organization (NARO), Kan-nondai, Tsukuba, Ibaraki, Japan
| | - Takumi Tanaka
- National Agriculture and Food Research Organization (NARO), Kan-nondai, Tsukuba, Ibaraki, Japan
| | - Hirokazu Ueda
- National Agriculture and Food Research Organization (NARO), Kan-nondai, Tsukuba, Ibaraki, Japan
| | - Akira Endo
- National Agriculture and Food Research Organization (NARO), Kan-nondai, Tsukuba, Ibaraki, Japan
| | - Tohru Yarimizu
- National Agriculture and Food Research Organization (NARO), Kan-nondai, Tsukuba, Ibaraki, Japan
| | - Etsuko Katoh
- National Agriculture and Food Research Organization (NARO), Kan-nondai, Tsukuba, Ibaraki, Japan
| | - Hiroko Kitamoto
- National Agriculture and Food Research Organization (NARO), Kan-nondai, Tsukuba, Ibaraki, Japan.
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Abstract
Microbial production of biofuels and bioproducts offers a sustainable and economic alternative to petroleum-based fuels and chemicals. The basidiomycete yeast Rhodosporidium toruloides is a promising platform organism for generating bioproducts due to its ability to consume a broad spectrum of carbon sources (including those derived from lignocellulosic biomass) and to naturally accumulate high levels of lipids and carotenoids, two biosynthetic pathways that can be leveraged to produce a wide range of bioproducts. While R. toruloides has great potential, it has a more limited set of tools for genetic engineering relative to more advanced yeast platform organisms such as Yarrowia lipolytica and Saccharomyces cerevisiae Significant advancements in the past few years have bolstered R. toruloides' engineering capacity. Here we expand this capacity by demonstrating the first use of CRISPR-Cas9-based gene disruption in R. toruloides Transforming a Cas9 expression cassette harboring nourseothricin resistance and selecting transformants on this antibiotic resulted in strains of R. toruloides exhibiting successful targeted disruption of the native URA3 gene. While editing efficiencies were initially low (0.002%), optimization of the cassette increased efficiencies 364-fold (to 0.6%). Applying these optimized design conditions enabled disruption of another native gene involved in carotenoid biosynthesis, CAR2, with much greater success; editing efficiencies of CAR2 deletion reached roughly 50%. Finally, we demonstrated efficient multiplexed genome editing by disrupting both CAR2 and URA3 in a single transformation. Together, our results provide a framework for applying CRISPR-Cas9 to R. toruloides that will facilitate rapid and high-throughput genome engineering in this industrially relevant organism.IMPORTANCE Microbial biofuel and bioproduct platforms provide access to clean and renewable carbon sources that are more sustainable and environmentally friendly than petroleum-based carbon sources. Furthermore, they can serve as useful conduits for the synthesis of advanced molecules that are difficult to produce through strictly chemical means. R. toruloides has emerged as a promising potential host for converting renewable lignocellulosic material into valuable fuels and chemicals. However, engineering efforts to improve the yeast's production capabilities have been impeded by a lack of advanced tools for genome engineering. While this is rapidly changing, one key tool remains unexplored in R. toruloides: CRISPR-Cas9. The results outlined here demonstrate for the first time how effective multiplexed CRISPR-Cas9 gene disruption provides a framework for other researchers to utilize this revolutionary genome-editing tool effectively in R. toruloides.
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Podolsky IA, Seppälä S, Lankiewicz TS, Brown JL, Swift CL, O'Malley MA. Harnessing Nature's Anaerobes for Biotechnology and Bioprocessing. Annu Rev Chem Biomol Eng 2019; 10:105-128. [PMID: 30883214 DOI: 10.1146/annurev-chembioeng-060718-030340] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Industrial biotechnology has the potential to decrease our reliance on petroleum for fuel and bio-based chemical production and also enable valorization of waste streams. Anaerobic microorganisms thrive in resource-limited environments and offer an array of novel bioactivities in this regard that could revolutionize biomanufacturing. However, they have not been adopted for widespread industrial use owing to their strict growth requirements, limited number of available strains, difficulty in scale-up, and genetic intractability. This review provides an overview of current and future uses for anaerobes in biotechnology and bioprocessing in the postgenomic era. We focus on the recently characterized anaerobic fungi (Neocallimastigomycota) native to the digestive tract of large herbivores, which possess a trove of enzymes, pathways, transporters, and other biomolecules that can be harnessed for numerous biotechnological applications. Resolving current genetic intractability, scale-up, and cultivation challenges will unlock the potential of these lignocellulolytic fungi and other nonmodel micro-organisms to accelerate bio-based production.
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Affiliation(s)
- Igor A Podolsky
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA; , , , , ,
| | - Susanna Seppälä
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA; , , , , ,
| | - Thomas S Lankiewicz
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA; , , , , ,
| | - Jennifer L Brown
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA; , , , , ,
| | - Candice L Swift
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA; , , , , ,
| | - Michelle A O'Malley
- Department of Chemical Engineering, University of California, Santa Barbara, California 93106, USA; , , , , ,
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Jiang H, Horwitz AA, Wright C, Tai A, Znameroski EA, Tsegaye Y, Warbington H, Bower BS, Alves C, Co C, Jonnalagadda K, Platt D, Walter JM, Natarajan V, Ubersax JA, Cherry JR, Love JC. Challenging the workhorse: Comparative analysis of eukaryotic micro-organisms for expressing monoclonal antibodies. Biotechnol Bioeng 2019; 116:1449-1462. [PMID: 30739333 PMCID: PMC6836876 DOI: 10.1002/bit.26951] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 01/31/2019] [Accepted: 02/06/2019] [Indexed: 01/09/2023]
Abstract
For commercial protein therapeutics, Chinese hamster ovary (CHO) cells have an established history of safety, proven capability to express a wide range of therapeutic proteins and high volumetric productivities. Expanding global markets for therapeutic proteins and increasing concerns for broadened access of these medicines has catalyzed consideration of alternative approaches to this platform. Reaching these objectives likely will require an order of magnitude increase in volumetric productivity and a corresponding reduction in the costs of manufacture. For CHO-based manufacturing, achieving this combination of targeted improvements presents challenges. Based on a holistic analysis, the choice of host cells was identified as the single most influential factor for both increasing productivity and decreasing costs. Here we evaluated eight wild-type eukaryotic micro-organisms with prior histories of recombinant protein expression. The evaluation focused on assessing the potential of each host, and their corresponding phyla, with respect to key attributes relevant for manufacturing, namely (a) growth rates in industry-relevant media, (b) adaptability to modern techniques for genome editing, and (c) initial characterization of product quality. These characterizations showed that multiple organisms may be suitable for production with appropriate engineering and development and highlighted that yeast in general present advantages for rapid genome engineering and development cycles.
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Affiliation(s)
- Hanxiao Jiang
- Research and Development, Amyris Inc., Emeryville, California
| | | | - Chapman Wright
- Engineering & Technology, Biogen, Cambridge, Massachusetts
| | - Anna Tai
- Research and Development, Amyris Inc., Emeryville, California
| | | | - Yoseph Tsegaye
- Research and Development, Amyris Inc., Emeryville, California
| | | | | | | | - Carl Co
- Engineering & Technology, Biogen, Cambridge, Massachusetts
| | | | - Darren Platt
- Research and Development, Amyris Inc., Emeryville, California
| | | | | | | | - Joel R Cherry
- Research and Development, Amyris Inc., Emeryville, California
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Leynaud-Kieffer LMC, Curran SC, Kim I, Magnuson JK, Gladden JM, Baker SE, Simmons BA. A new approach to Cas9-based genome editing in Aspergillus niger that is precise, efficient and selectable. PLoS One 2019; 14:e0210243. [PMID: 30653574 PMCID: PMC6336261 DOI: 10.1371/journal.pone.0210243] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2018] [Accepted: 12/19/2018] [Indexed: 02/06/2023] Open
Abstract
Aspergillus niger and other filamentous fungi are widely used in industry, but efficient genetic engineering of these hosts remains nascent. For example, while molecular genetic tools have been developed, including CRISPR/Cas9, facile genome engineering of A. niger remains challenging. To address these challenges, we have developed a simple Cas9-based gene targeting method that provides selectable, iterative, and ultimately marker-free generation of genomic deletions and insertions. This method leverages locus-specific “pop-out” recombination to suppress off-target integrations. We demonstrated the effectiveness of this method by targeting the phenotypic marker albA and validated it by targeting the glaA and mstC loci. After two selection steps, we observed 100% gene editing efficiency across all three loci. This method greatly reduces the effort required to engineer the A. niger genome and overcomes low Cas9 transformations efficiency by eliminating the need for extensive screening. This method represents a significant addition to the A. niger genome engineering toolbox and could be adapted for use in other organisms. It is expected that this method will impact several areas of industrial biotechnology, such as the development of new strains for the secretion of heterologous enzymes and the discovery and optimization of metabolic pathways.
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Affiliation(s)
- Laure M. C. Leynaud-Kieffer
- Swiss Federal Institute of Technology Lausanne, Lausanne, Vaud, Switzerland
- Joint Bioenergy Institute, Emeryville, CA, United States of America
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States of America
| | - Samuel C. Curran
- Joint Bioenergy Institute, Emeryville, CA, United States of America
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States of America
- Comparative Biochemistry Graduate Group, University of California Berkeley, Berkeley, CA, United States of America
| | - Irene Kim
- Department of Chemistry, University of California, Berkeley, CA, United States of America
| | - Jon K. Magnuson
- Joint Bioenergy Institute, Emeryville, CA, United States of America
- Chemical and Biological Process Development Group, Pacific Northwest National Laboratory, Richland, WA, United States of America
| | - John M. Gladden
- Joint Bioenergy Institute, Emeryville, CA, United States of America
- Department of Biomass Science and Conversion Technology, Sandia National Laboratories, Livermore, CA, United States of America
| | - Scott E. Baker
- Joint Bioenergy Institute, Emeryville, CA, United States of America
- Biosystems Design and Simulation Group, Environmental Molecular Sciences Division, Pacific Northwest National Laboratory, Richland, WA, United States of America
| | - Blake A. Simmons
- Joint Bioenergy Institute, Emeryville, CA, United States of America
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States of America
- * E-mail:
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International Space Station conditions alter genomics, proteomics, and metabolomics in Aspergillus nidulans. Appl Microbiol Biotechnol 2018; 103:1363-1377. [PMID: 30539259 DOI: 10.1007/s00253-018-9525-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2018] [Revised: 11/13/2018] [Accepted: 11/16/2018] [Indexed: 12/30/2022]
Abstract
The first global genomic, proteomic, and secondary metabolomic characterization of the filamentous fungus Aspergillus nidulans following growth onboard the International Space Station (ISS) is reported. The investigation included the A. nidulans wild-type and three mutant strains, two of which were genetically engineered to enhance secondary metabolite production. Whole genome sequencing revealed that ISS conditions altered the A. nidulans genome in specific regions. In strain CW12001, which features overexpression of the secondary metabolite global regulator laeA, ISS conditions induced the loss of the laeA stop codon. Differential expression of proteins involved in stress response, carbohydrate metabolic processes, and secondary metabolite biosynthesis was also observed. ISS conditions significantly decreased prenyl xanthone production in the wild-type strain and increased asperthecin production in LO1362 and CW12001, which are deficient in a major DNA repair mechanism. These data provide valuable insights into the adaptation mechanism of A. nidulans to spacecraft environments.
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Dai Z, Pomraning KR, Deng S, Hofstad BA, Panisko EA, Rodriguez D, Butcher MG, Culley DE, Magnuson JK. Deletion of the KU70 homologue facilitates gene targeting in Lipomyces starkeyi strain NRRL Y-11558. Curr Genet 2018; 65:269-282. [DOI: 10.1007/s00294-018-0875-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 08/06/2018] [Accepted: 08/09/2018] [Indexed: 10/28/2022]
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Abstract
In the present chapter, we present the protocols and guidelines to facilitate implementation of CRISPR-Cas9 technology in fungi where few or no genetic tools are in place. Hence, we firstly explain how to identify dominant markers for genetic transformation. Secondly, we provide a guide for construction of Cas9/sgRNA episomal expression vectors. Thirdly, we present how to mutagenize reporter genes to explore the efficiency of CRISPR-Cas9 in the relevant fungus and to ease subsequent CRISPR-mediated genetic engineering. Lastly, we describe how to make CRISPR-mediated marker-dependent and marker-free gene targeting.
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Affiliation(s)
- Jakob B Hoof
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs.Lyngby, Denmark
| | - Christina S Nødvig
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs.Lyngby, Denmark
| | - Uffe H Mortensen
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs.Lyngby, Denmark.
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Ito-Harashima S, Yagi T. Unique molecular mechanisms for maintenance and alteration of genetic information in the budding yeast Saccharomyces cerevisiae. Genes Environ 2017; 39:28. [PMID: 29213342 PMCID: PMC5709847 DOI: 10.1186/s41021-017-0088-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2017] [Accepted: 10/26/2017] [Indexed: 11/10/2022] Open
Abstract
The high-fidelity transmission of genetic information is crucial for the survival of organisms, the cells of which have the ability to protect DNA against endogenous and environmental agents, including reactive oxygen species (ROS), ionizing radiation, and various chemical compounds. The basis of protection mechanisms has been evolutionarily conserved from yeast to humans; however, each organism often has a specialized mode of regulation that uses different sets of machineries, particularly in lower eukaryotes. The divergence of molecular mechanisms among related organisms has provided insights into the evolution of cellular machineries to a higher architecture. Uncommon characteristics of machineries may also contribute to the development of new applications such as drugs with novel mechanisms of action. In contrast to the cellular properties for maintaining genetic information, living organisms, particularly microbes, inevitably undergo genetic alterations in order to adapt to environmental conditions. The maintenance and alteration of genetic information may be inextricably linked to each other. In this review, we describe recent findings on the unconventional molecular mechanisms of DNA damage response and DNA double-strand break (DSB) repair in the budding yeast Saccharomyces cerevisiae. We also introduce our previous research on genetic and phenotypic instabilities observed in a clonal population of clinically-derived S. cerevisiae. The molecular mechanisms of this case were associated with mutations to generate tyrosine-inserting tRNA-Tyr ochre suppressors and the position effects of mutation frequencies among eight tRNA-Tyr loci dispersed in the genome. Phenotypic variations among different strain backgrounds have also been observed by another type of nonsense suppressor, the aberrant form of the translation termination factor. Nonsense suppressors are considered to be responsible for the genome-wide translational readthrough of termination codons, including natural nonsense codons. The nonsense suppressor-mediated acquisition of phenotypic variations may be advantageous for adaptation to environmental conditions and survival during evolution.
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Affiliation(s)
- Sayoko Ito-Harashima
- Department of Biological Sciences, Graduate School of Science, Osaka Prefecture University, 1-2 Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8570 Japan
| | - Takashi Yagi
- Department of Biological Sciences, Graduate School of Science, Osaka Prefecture University, 1-2 Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8570 Japan
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Kamaruddin N, Storms R, Mahadi NM, Illias RM, Bakar FDA, Murad AMA. Reduction of Extracellular Proteases Increased Activity and Stability of Heterologous Protein in $${ Aspergillus}$$ A s p e r g i l l u s $${ niger}$$ n i g e r. ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING 2017. [DOI: 10.1007/s13369-017-2914-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Shao S, Ren C, Liu Z, Bai Y, Chen Z, Wei Z, Wang X, Zhang Z, Xu K. Enhancing CRISPR/Cas9-mediated homology-directed repair in mammalian cells by expressing Saccharomyces cerevisiae Rad52. Int J Biochem Cell Biol 2017; 92:43-52. [DOI: 10.1016/j.biocel.2017.09.012] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2017] [Revised: 09/09/2017] [Accepted: 09/15/2017] [Indexed: 12/01/2022]
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Development of a CRISPR-Cas9 System for Efficient Genome Editing of Candida lusitaniae. mSphere 2017; 2:mSphere00217-17. [PMID: 28657072 PMCID: PMC5480034 DOI: 10.1128/msphere.00217-17] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Accepted: 05/29/2017] [Indexed: 11/20/2022] Open
Abstract
Candida lusitaniae is a member of the Candida clade that includes a diverse group of fungal species relevant to both human health and biotechnology. This species exhibits a full sexual cycle to undergo interconversion between haploid and diploid forms. C. lusitaniae is also an emerging opportunistic pathogen that can cause serious bloodstream infections in the clinic and yet has often proven to be refractory to facile genetic manipulations. In this work, we develop a clustered regularly interspaced short palindromic repeat (CRISPR) and CRISPR-associated gene 9 (Cas9) system to enable genome editing of C. lusitaniae. We demonstrate that expression of CRISPR-Cas9 components under species-specific promoters is necessary for efficient gene targeting and can be successfully applied to multiple genes in both haploid and diploid isolates. Gene deletion efficiencies with CRISPR-Cas9 were further enhanced in C. lusitaniae strains lacking the established nonhomologous end joining (NHEJ) factors Ku70 and DNA ligase 4. These results indicate that NHEJ plays an important role in directing the repair of DNA double-strand breaks (DSBs) in C. lusitaniae and that removal of this pathway increases integration of gene deletion templates by homologous recombination. The described approaches significantly enhance the ability to perform genetic studies in, and promote understanding of, this emerging human pathogen and model sexual species. IMPORTANCE The ability to perform efficient genome editing is a key development for detailed mechanistic studies of a species. Candida lusitaniae is an important member of the Candida clade and is relevant both as an emerging human pathogen and as a model for understanding mechanisms of sexual reproduction. We highlight the development of a CRISPR-Cas9 system for efficient genome manipulation in C. lusitaniae and demonstrate the importance of species-specific promoters for expression of CRISPR components. We also demonstrate that the NHEJ pathway contributes to non-template-mediated repair of DNA DSBs and that removal of this pathway enhances efficiencies of gene targeting by CRISPR-Cas9. These results therefore establish important genetic tools for further exploration of C. lusitaniae biology.
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