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Haque MA, Nath ND, Johnston TV, Haruna S, Ahn J, Ovissipour R, Ku S. Harnessing biotechnology for penicillin production: Opportunities and environmental considerations. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 946:174236. [PMID: 38942308 DOI: 10.1016/j.scitotenv.2024.174236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 06/20/2024] [Accepted: 06/21/2024] [Indexed: 06/30/2024]
Abstract
Since the discovery of antibiotics, penicillin has remained the top choice in clinical medicine. With continuous advancements in biotechnology, penicillin production has become cost-effective and efficient. Genetic engineering techniques have been employed to enhance biosynthetic pathways, leading to the production of new penicillin derivatives with improved properties and increased efficacy against antibiotic-resistant pathogens. Advances in bioreactor design, media formulation, and process optimization have contributed to higher yields, reduced production costs, and increased penicillin accessibility. While biotechnological advances have clearly benefited the global production of this life-saving drug, they have also created challenges in terms of waste management. Production fermentation broths from industries contain residual antibiotics, by-products, and other contaminants that pose direct environmental threats, while increased global consumption intensifies the risk of antimicrobial resistance in both the environment and living organisms. The current geographical and spatial distribution of antibiotic and penicillin consumption dramatically reveals a worldwide threat. These challenges are being addressed through the development of novel waste management techniques. Efforts are aimed at both upstream and downstream processing of antibiotic and penicillin production to minimize costs and improve yield efficiency while lowering the overall environmental impact. Yield optimization using artificial intelligence (AI), along with biological and chemical treatment of waste, is also being explored to reduce adverse impacts. The implementation of strict regulatory frameworks and guidelines is also essential to ensure proper management and disposal of penicillin production waste. This review is novel because it explores the key remaining challenges in antibiotic development, the scope of machine learning tools such as Quantitative Structure-Activity Relationship (QSAR) in modern biotechnology-driven production, improved waste management for antibiotics, discovering alternative path to reducing antibiotic use in agriculture through alternative meat production, addressing current practices, and offering effective recommendations.
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Affiliation(s)
- Md Ariful Haque
- Department of Food Science and Technology, Texas A&M University, College Station, USA.
| | - Nirmalendu Deb Nath
- Department of Biomedical and Diagnostic Sciences, University of Tennessee, Knoxville, USA.
| | - Tony Vaughn Johnston
- Fermentation Science Program, School of Agriculture, College of Basic and Applied Sciences, Middle Tennessee State University, Murfreesboro, USA.
| | - Samuel Haruna
- Fermentation Science Program, School of Agriculture, College of Basic and Applied Sciences, Middle Tennessee State University, Murfreesboro, USA.
| | - Jaehyun Ahn
- Department of Food Science and Technology, Texas A&M University, College Station, USA.
| | - Reza Ovissipour
- Department of Food Science and Technology, Texas A&M University, College Station, USA.
| | - Seockmo Ku
- Department of Food Science and Technology, Texas A&M University, College Station, USA.
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Zhang YD, Ji XB, Zong J, Dai XF, Klosterman SJ, Subbarao KV, Zhang DD, Chen JY. Functional analysis of the mating type genes in Verticillium dahliae. BMC Biol 2024; 22:108. [PMID: 38714997 PMCID: PMC11077750 DOI: 10.1186/s12915-024-01900-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 04/22/2024] [Indexed: 05/12/2024] Open
Abstract
BACKGROUND Populations of the plant pathogenic fungus Verticillium dahliae display a complex and rich genetic diversity, yet the existence of sexual reproduction in the fungus remains contested. As pivotal genes, MAT genes play a crucial role in regulating cell differentiation, morphological development, and mating of compatible cells. However, the functions of the two mating type genes in V. dahliae, VdMAT1-1-1, and VdMAT1-2-1, remain poorly understood. RESULTS In this study, we confirmed that the MAT loci in V. dahliae are highly conserved, including both VdMAT1-1-1 and VdMAT1-2-1 which share high collinearity. The conserved core transcription factor encoded by the two MAT loci may facilitate the regulation of pheromone precursor and pheromone receptor genes by directly binding to their promoter regions. Additionally, peptide activity assays demonstrated that the signal peptide of the pheromone VdPpg1 possessed secretory activity, while VdPpg2, lacked a predicted signal peptide. Chemotactic growth assays revealed that V. dahliae senses and grows towards the pheromones FO-a and FO-α of Fusarium oxysporum, as well as towards VdPpg2 of V. dahliae, but not in response to VdPpg1. The findings herein also revealed that VdMAT1-1-1 and VdMAT1-2-1 regulate vegetative growth, carbon source utilization, and resistance to stressors in V. dahliae, while negatively regulating virulence. CONCLUSIONS These findings underscore the potential roles of VdMAT1-1-1 and VdMAT1-2-1 in sexual reproduction and confirm their involvement in various asexual processes of V. dahliae, offering novel insights into the functions of mating type genes in this species.
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Affiliation(s)
- Ya-Duo Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Xiao-Bin Ji
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Juan Zong
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Xiao-Feng Dai
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China
| | - Steven J Klosterman
- United States Department of Agriculture, Agricultural Research Service, Salinas, CA, USA
| | - Krishna V Subbarao
- Department of Plant Pathology, University of California, Davis, c/o United States Agricultural Research Station, Salinas, CA, USA.
| | - Dan-Dan Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
- Western Agricultural Research Center, Chinese Academy of Agricultural Sciences, Changji, 831100, China.
| | - Jie-Yin Chen
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, 100193, China.
- Western Agricultural Research Center, Chinese Academy of Agricultural Sciences, Changji, 831100, China.
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Hill R, McMullan M. Recombination triggers fungal crop disease. Nat Ecol Evol 2023; 7:1961-1962. [PMID: 37945943 DOI: 10.1038/s41559-023-02132-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
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Fariña-Flores D, Berbegal M, Iturritxa E, Hernandez-Escribano L, Aguín O, Raposo R. Temporal and Spatial Variation in the Population Structure of Spanish Fusarium circinatum Infecting Pine Stands. J Fungi (Basel) 2023; 9:jof9020159. [PMID: 36836273 PMCID: PMC9962447 DOI: 10.3390/jof9020159] [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: 12/19/2022] [Revised: 01/18/2023] [Accepted: 01/20/2023] [Indexed: 01/27/2023] Open
Abstract
Fusarium circinatum is an introduced fungal pathogen extended to the northern regions of Spain that causes Pine Pitch Canker (PPC) disease. In this work, we analyzed the pathogen's genetic diversity to study changes over time and space since the first outbreak occurred in Spain. Using six polymorphic SSR markers, 15 MLGs were identified in 66 isolates, and only three haplotypes were found with frequencies higher than one. In general, genotypic diversity was low and decreased shortly over time in the northwestern regions while maintained at País Vasco, where only one haplotype (MLG32) was detected 10 years. This population also included isolates of a single mating type (MAT-2) and VCGs identified in only two groups, while isolates from NW regions were of both mating types and VCGs represented in 11 groups. The existence of haplotype MLG32 maintained on time and widely distributed suggests its good adaptation to the environment and the host. Results showed that the pathogen in País Vasco remains clearly differentiated from other northwestern populations. This fact was supported with no evidence of migration among regions. Results are explained by the asexual reproduction, but also selfing at least to a lesser extent that leads to identification of two new haplotypes.
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Affiliation(s)
- David Fariña-Flores
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, 28040 Madrid, Spain
- Instituto de Ciencias Forestales (ICIFOR-INIA), CSIC, Carretera Coruña km 7.5, 28040 Madrid, Spain
| | - Mónica Berbegal
- Instituto Agroforestal Mediterráneo, Universitat Politècnica de València, Camino de Vera s/n, 46022 Valencia, Spain
- Correspondence:
| | - Eugenia Iturritxa
- NEIKER, Granja Modelo—Arkaute, Apdo. 46, 01080 Vitoria-Gasteiz, Spain
| | | | - Olga Aguín
- Estación Fitopatolóxica Areeiro, Diputación Pontevedra, 36153 Pontevedra, Spain
| | - Rosa Raposo
- Instituto de Ciencias Forestales (ICIFOR-INIA), CSIC, Carretera Coruña km 7.5, 28040 Madrid, Spain
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Fierro F, Vaca I, Castillo NI, García-Rico RO, Chávez R. Penicillium chrysogenum, a Vintage Model with a Cutting-Edge Profile in Biotechnology. Microorganisms 2022; 10:microorganisms10030573. [PMID: 35336148 PMCID: PMC8954384 DOI: 10.3390/microorganisms10030573] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 02/15/2022] [Accepted: 02/17/2022] [Indexed: 12/20/2022] Open
Abstract
The discovery of penicillin entailed a decisive breakthrough in medicine. No other medical advance has ever had the same impact in the clinical practise. The fungus Penicillium chrysogenum (reclassified as P. rubens) has been used for industrial production of penicillin ever since the forties of the past century; industrial biotechnology developed hand in hand with it, and currently P. chrysogenum is a thoroughly studied model for secondary metabolite production and regulation. In addition to its role as penicillin producer, recent synthetic biology advances have put P. chrysogenum on the path to become a cell factory for the production of metabolites with biotechnological interest. In this review, we tell the history of P. chrysogenum, from the discovery of penicillin and the first isolation of strains with high production capacity to the most recent research advances with the fungus. We will describe how classical strain improvement programs achieved the goal of increasing production and how the development of different molecular tools allowed further improvements. The discovery of the penicillin gene cluster, the origin of the penicillin genes, the regulation of penicillin production, and a compilation of other P. chrysogenum secondary metabolites will also be covered and updated in this work.
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Affiliation(s)
- Francisco Fierro
- Departamento de Biotecnología, Universidad Autónoma Metropolitana-Unidad Iztapalapa, Ciudad de México 09340, Mexico
- Correspondence:
| | - Inmaculada Vaca
- Departamento de Química, Facultad de Ciencias, Universidad de Chile, Santiago 7800003, Chile;
| | - Nancy I. Castillo
- Grupo de Investigación en Ciencias Biológicas y Químicas, Facultad de Ciencias, Universidad Antonio Nariño, Bogotá 110231, Colombia;
| | - Ramón Ovidio García-Rico
- Grupo de Investigación GIMBIO, Departamento De Microbiología, Facultad de Ciencias Básicas, Universidad de Pamplona, Pamplona 543050, Colombia;
| | - Renato Chávez
- Departamento de Biología, Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago 9170020, Chile;
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Yamamoto N, Watarai N, Koyano H, Sawada K, Toyoda A, Kurokawa K, Yamada T. Analysis of genomic characteristics and their influence on metabolism in Aspergillus luchuensis albino mutants using genome sequencing. Fungal Genet Biol 2021; 155:103601. [PMID: 34224861 DOI: 10.1016/j.fgb.2021.103601] [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: 06/23/2019] [Revised: 06/17/2021] [Accepted: 06/18/2021] [Indexed: 10/21/2022]
Abstract
Black Aspergillus luchuensis and its white albino mutant are essential fungi for making alcoholic beverages in Japan. A large number of industrial strains have been created using novel isolation or gene/genome mutation techniques. Such mutations influence metabolic and phenotypic characteristics in industrial strains, but few comparative studies of inter-strain mutation have been conducted. We carried out comparative genome analyses of 8 industrial strains of A. luchuensis and A. kawachii IFO 4308, the latter being the first albino strain to be isolated. Phylogenetic analysis based on 8938 concatenated genes exposed the diversity of black koji strains and uniformity among albino industrial strains, suggesting that passaged industrial albino strains have more genetic mutations compared with strain IFO 4308 and black koji strains. Comparative analysis showed that the albino strains had mutations in genes not only for conidial pigmentation but also in those that encode N-terminal acetyltransferase A and annexin XIV-like protein. The results also suggest that some mutations may have emerged through subculturing of albino strains. For example, mutations in the genes for isocitrate lyase and sugar transporters were observed only in industrial albino strains. This implies that selective pressure for increasing enzyme activity or secondary metabolites may have influenced the mutation of genes associated with environmental stress responses in A. luchuensis albino strains. Our study clarifies hitherto unknown genetic and metabolic characteristics of A. luchuensis industrial strains and provides potential applications for comparative genome analysis for breeding koji strains.
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Affiliation(s)
- Nozomi Yamamoto
- Department of Life Science and Technology, Tokyo Institute of Technology, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8550, Japan
| | - Naoki Watarai
- Department of Life Science and Technology, Tokyo Institute of Technology, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8550, Japan
| | - Hitoshi Koyano
- Department of Life Science and Technology, Tokyo Institute of Technology, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8550, Japan
| | - Kazunori Sawada
- Corporate Strategy Office, Gurunavi, Inc., Toho Hibiya Building, 1-2-2 Yurakucho, Chiyoda-ku, Tokyo 100-0006, Japan
| | - Atsushi Toyoda
- Department of Genomics and Evolutionary Biology, National Institute of Genetics, Yata 1111, Mishima, Shizuoka 411-8540, Japan
| | - Ken Kurokawa
- Department of Informatics, National Institute of Genetics, Yata 1111, Mishima, Shizuoka 411-8540, Japan
| | - Takuji Yamada
- Department of Life Science and Technology, Tokyo Institute of Technology, 2-12-1, Ookayama, Meguro-ku, Tokyo 152-8550, Japan.
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Biological Characteristics of Verticillium dahliae MAT1-1 and MAT1-2 Strains. Int J Mol Sci 2021; 22:ijms22137148. [PMID: 34281204 PMCID: PMC8269371 DOI: 10.3390/ijms22137148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 06/25/2021] [Accepted: 06/29/2021] [Indexed: 12/17/2022] Open
Abstract
Verticillium dahliae is a soil-borne plant pathogenic fungus that causes Verticillium wilt on hundreds of dicotyledonous plant species. V. dahliae is considered an asexually (clonal) reproducing fungus, although both mating type idiomorphs (MAT1-1 and MAT1-2) are present, and is heterothallic. Most of the available information on V. dahliae strains, including their biology, pathology, and genomics comes from studies on isolates with the MAT1-2 idiomorph, and thus little information is available on the MAT1-1 V. dahliae strains in the literature. We therefore evaluated the growth responses of MAT1-1 and MAT1-2 V. dahliae strains to various stimuli. Growth rates and melanin production in response to increased temperature, alkaline pH, light, and H2O2 stress were higher in the MAT1-2 strains than in the MAT1-1 strains. In addition, the MAT1-2 strains showed an enhanced ability to degrade complex polysaccharides, especially starch, pectin, and cellulose. Furthermore, several MAT1-2 strains from both potato and sunflower showed increased virulence on their original hosts, relative to their MAT1-1 counterparts. Thus, compared to MAT1-1 strains, MAT1-2 strains derive their potentially greater fitness from an increased capacity to adapt to their environment and exhibit higher virulence. These competitive advantages might explain the current abundance of MAT1-2 strains relative to MAT1-1 strains in the agricultural and sylvicultural ecosystems, and this study provides the baseline information on the two mating idiomorphs to study sexual reproduction in V. dahliae under natural and laboratory conditions.
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Alonso-García M, Grewe F, Payette S, Villarreal A JC. Population genomics of a reindeer lichen species from North American lichen woodlands. AMERICAN JOURNAL OF BOTANY 2021; 108:159-171. [PMID: 33512730 DOI: 10.1002/ajb2.1601] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 09/28/2020] [Indexed: 06/12/2023]
Abstract
PREMISE Lichens are one of the main structural components of plant communities in the North American boreal biome. They play a pivotal role in lichen woodlands, a large ecosystem situated north of the closed-crown forest zone, and south of the forest-tundra zone. In Eastern Canada (Quebec), there is a remnant LW found 500 km south of its usual distribution range, in the Parc National des Grands-Jardins, originated mainly because of wildfires. We inferred the origin of the lichen Cladonia stellaris from this LW and assessed its genetic diversity in a postfire succession. METHODS We genotyped 122 individuals collected across a latitudinal gradient in Quebec. Using the software Stacks, we compared four different approaches of locus selection and single-nucleotide polymorphism calling. We identified the best fitting approach to investigate population structure and estimate genetic diversity of C. stellaris. RESULTS Populations in southern Quebec are not genetically different from those of northern LWs. The species consists of at least four phylogenetic lineages with elevated levels of genetic diversity and low co-ancestry. In Parc National des Grands-Jardins, we reported high values of genetic diversity not related with time since fire disturbance and low genetic differentiation among populations with different fire histories. CONCLUSIONS This first population genomic study of C. stellaris is an important step forward to understand the origin and biogeographic patterns of lichen woodlands in North America. Our findings also contribute to the understanding of the effect of postfire succession on the genetic structure of the species.
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Affiliation(s)
- Marta Alonso-García
- Département de Biologie, Université Laval, Québec, G1V 0A6, Canada
- Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, G1V 0A6, Canada
| | - Felix Grewe
- The Field Museum, Grainger Bioinformatics Center, 1400 South Lake Shore Drive, Chicago, 60605, USA
| | - Serge Payette
- Département de Biologie, Université Laval, Québec, G1V 0A6, Canada
| | - Juan Carlos Villarreal A
- Département de Biologie, Université Laval, Québec, G1V 0A6, Canada
- Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec, G1V 0A6, Canada
- Royal Botanic Garden Edinburgh, 20A Inverleith Row, EH3 5LR, Scotland, UK
- Smithsonian Tropical Research Institute, Panama City, Panama
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10
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Wilken PM, Aylward J, Chand R, Grewe F, Lane FA, Sinha S, Ametrano C, Distefano I, Divakar PK, Duong TA, Huhndorf S, Kharwar RN, Lumbsch HT, Navathe S, Pérez CA, Ramírez-Berrutti N, Sharma R, Sun Y, Wingfield BD, Wingfield MJ. IMA Genome - F13: Draft genome sequences of Ambrosiella cleistominuta, Cercospora brassicicola, C. citrullina, Physcia stellaris, and Teratosphaeria pseudoeucalypti. IMA Fungus 2020; 11:19. [PMID: 33014691 PMCID: PMC7513301 DOI: 10.1186/s43008-020-00039-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Draft genomes of the fungal species Ambrosiella cleistominuta, Cercospora brassicicola, C. citrullina, Physcia stellaris, and Teratosphaeria pseudoeucalypti are presented. Physcia stellaris is an important lichen forming fungus and Ambrosiella cleistominuta is an ambrosia beetle symbiont. Cercospora brassicicola and C. citrullina are agriculturally relevant plant pathogens that cause leaf-spots in brassicaceous vegetables and cucurbits respectively. Teratosphaeria pseudoeucalypti causes severe leaf blight and defoliation of Eucalyptus trees. These genomes provide a valuable resource for understanding the molecular processes in these economically important fungi.
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Affiliation(s)
- P. Markus Wilken
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private Bag x20, Hatfield, Pretoria, 0028 South Africa
| | - Janneke Aylward
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private Bag x20, Hatfield, Pretoria, 0028 South Africa
- Department of Conservation Ecology and Entomology, Stellenbosch University, Private Bag X1, Matieland, 7602 South Africa
| | - Ramesh Chand
- Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, 221005 India
| | - Felix Grewe
- Field Museum, Department of Science and Education, Grainger Bioinformatics Center, Chicago, IL USA
| | - Frances A. Lane
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private Bag x20, Hatfield, Pretoria, 0028 South Africa
| | - Shagun Sinha
- Institute of Agricultural Sciences, Banaras Hindu University, Varanasi, 221005 India
- Center of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi, 221005 India
| | - Claudio Ametrano
- Field Museum, Department of Science and Education, Grainger Bioinformatics Center, Chicago, IL USA
| | - Isabel Distefano
- Field Museum, Department of Science and Education, Grainger Bioinformatics Center, Chicago, IL USA
| | - Pradeep K. Divakar
- Departamento de Farmacología, Farmacognosia y Botánica, Facultad de Farmacia, Universidad Complutense de Madrid, Plaza de Ramón y Cajal s/n, 28040 Madrid, Spain
| | - Tuan A. Duong
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private Bag x20, Hatfield, Pretoria, 0028 South Africa
| | - Sabine Huhndorf
- Field Museum, Department of Science and Education, Grainger Bioinformatics Center, Chicago, IL USA
| | - Ravindra N. Kharwar
- Center of Advanced Study in Botany, Institute of Science, Banaras Hindu University, Varanasi, 221005 India
| | - H. Thorsten Lumbsch
- Field Museum, Department of Science and Education, Grainger Bioinformatics Center, Chicago, IL USA
| | - Sudhir Navathe
- Agharkar Research Institute, G.G. Agharkar Road, Pune, 411004 India
| | - Carlos A. Pérez
- Department of Plant Protection, EEMAC, Facultad de Agronomía, UdelaR, Paysandú, Uruguay
| | | | - Rohit Sharma
- National Centre for Microbial Resource, National Centre for Cell Science, S.P, Pune University, Pune, 411 007 India
| | - Yukun Sun
- Field Museum, Department of Science and Education, Grainger Bioinformatics Center, Chicago, IL USA
| | - Brenda D. Wingfield
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private Bag x20, Hatfield, Pretoria, 0028 South Africa
| | - Michael J. Wingfield
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private Bag x20, Hatfield, Pretoria, 0028 South Africa
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Lücking R, Aime MC, Robbertse B, Miller AN, Ariyawansa HA, Aoki T, Cardinali G, Crous PW, Druzhinina IS, Geiser DM, Hawksworth DL, Hyde KD, Irinyi L, Jeewon R, Johnston PR, Kirk PM, Malosso E, May TW, Meyer W, Öpik M, Robert V, Stadler M, Thines M, Vu D, Yurkov AM, Zhang N, Schoch CL. Unambiguous identification of fungi: where do we stand and how accurate and precise is fungal DNA barcoding? IMA Fungus 2020; 11:14. [PMID: 32714773 PMCID: PMC7353689 DOI: 10.1186/s43008-020-00033-z] [Citation(s) in RCA: 182] [Impact Index Per Article: 45.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
True fungi (Fungi) and fungus-like organisms (e.g. Mycetozoa, Oomycota) constitute the second largest group of organisms based on global richness estimates, with around 3 million predicted species. Compared to plants and animals, fungi have simple body plans with often morphologically and ecologically obscure structures. This poses challenges for accurate and precise identifications. Here we provide a conceptual framework for the identification of fungi, encouraging the approach of integrative (polyphasic) taxonomy for species delimitation, i.e. the combination of genealogy (phylogeny), phenotype (including autecology), and reproductive biology (when feasible). This allows objective evaluation of diagnostic characters, either phenotypic or molecular or both. Verification of identifications is crucial but often neglected. Because of clade-specific evolutionary histories, there is currently no single tool for the identification of fungi, although DNA barcoding using the internal transcribed spacer (ITS) remains a first diagnosis, particularly in metabarcoding studies. Secondary DNA barcodes are increasingly implemented for groups where ITS does not provide sufficient precision. Issues of pairwise sequence similarity-based identifications and OTU clustering are discussed, and multiple sequence alignment-based phylogenetic approaches with subsequent verification are recommended as more accurate alternatives. In metabarcoding approaches, the trade-off between speed and accuracy and precision of molecular identifications must be carefully considered. Intragenomic variation of the ITS and other barcoding markers should be properly documented, as phylotype diversity is not necessarily a proxy of species richness. Important strategies to improve molecular identification of fungi are: (1) broadly document intraspecific and intragenomic variation of barcoding markers; (2) substantially expand sequence repositories, focusing on undersampled clades and missing taxa; (3) improve curation of sequence labels in primary repositories and substantially increase the number of sequences based on verified material; (4) link sequence data to digital information of voucher specimens including imagery. In parallel, technological improvements to genome sequencing offer promising alternatives to DNA barcoding in the future. Despite the prevalence of DNA-based fungal taxonomy, phenotype-based approaches remain an important strategy to catalog the global diversity of fungi and establish initial species hypotheses.
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Affiliation(s)
- Robert Lücking
- Botanischer Garten und Botanisches Museum, Freie Universität Berlin, Königin-Luise-Straße 6–8, 14195 Berlin, Germany
- International Commission on the Taxonomy of Fungi, Champaign, IL USA
| | - M. Catherine Aime
- International Commission on the Taxonomy of Fungi, Champaign, IL USA
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907 USA
| | - Barbara Robbertse
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, 45 Center Drive, Bethesda, MD 20892 USA
| | - Andrew N. Miller
- International Commission on the Taxonomy of Fungi, Champaign, IL USA
- Illinois Natural History Survey, University of Illinois, 1816 South Oak Street, Champaign, IL 61820-6970 USA
| | - Hiran A. Ariyawansa
- International Commission on the Taxonomy of Fungi, Champaign, IL USA
- Department of Plant Pathology and Microbiology, College of Bio-Resources and Agriculture, National Taiwan University, Taipe City, Taiwan
| | - Takayuki Aoki
- International Commission on the Taxonomy of Fungi, Champaign, IL USA
- National Agriculture and Food Research Organization, Genetic Resources Center, 2-1-2 Kannondai, Tsukuba, Ibaraki, 305-8602 Japan
| | - Gianluigi Cardinali
- Department Pharmaceutical Sciences, University of Perugia, Via Borgo 20 Giugno, 74, Perugia, Italy
| | - Pedro W. Crous
- International Commission on the Taxonomy of Fungi, Champaign, IL USA
- Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
- Wageningen University and Research Centre (WUR), Laboratory of Phytopathology, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| | - Irina S. Druzhinina
- International Commission on the Taxonomy of Fungi, Champaign, IL USA
- Microbiology and Applied Genomics Group, Research Area Biochemical Technology, Institute of Chemical, Environmental & Bioscience Engineering (ICEBE), TU Wien, Vienna, Austria
- Jiangsu Provincial Key Lab of Organic Solid Waste Utilization, Nanjing Agricultural University, Nanjing, China
| | - David M. Geiser
- Department of Plant Pathology & Environmental Microbiology, The Pennsylvania State University, University Park, PA 16802 USA
| | - David L. Hawksworth
- International Commission on the Taxonomy of Fungi, Champaign, IL USA
- Department of Life Sciences, The Natural History Museum, Cromwell Road, London, SW7 5BD UK
- Comparative Plant and Fungal Biology, Royal Botanic Gardens, Kew, Surrey, TW9 3DS UK
- Geography and Environment, University of Southampton, Southampton, SO17 1BJ UK
- Jilin Agricultural University, Changchun, 130118 Jilin Province China
| | - Kevin D. Hyde
- International Commission on the Taxonomy of Fungi, Champaign, IL USA
- Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Science, Kunming, 650201 Yunnan China
- Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai, 57100 Thailand
- World Agroforestry Centre, East and Central Asia, Kunming, 650201 Yunnan China
- Mushroom Research Foundation, 128 M.3 Ban Pa Deng T. Pa Pae, A. Mae Taeng, Chiang Rai, 50150 Thailand
| | - Laszlo Irinyi
- Molecular Mycology Research Laboratory, Centre for Infectious Diseases and Microbiology, Faculty of Medicine and Health, Sydney Medical School, Westmead Clinical School, Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Westmead Hospital (Research and Education Network), Westmead Institute for Medical Research, Sydney, NSW Australia
| | - Rajesh Jeewon
- Department of Health Sciences, Faculty of Science, University of Mauritius, Reduit, Mauritius
| | - Peter R. Johnston
- International Commission on the Taxonomy of Fungi, Champaign, IL USA
- Manaaki Whenua – Landcare Research, Private Bag 92170, Auckland, 1142 New Zealand
| | | | - Elaine Malosso
- International Commission on the Taxonomy of Fungi, Champaign, IL USA
- Universidade Federal de Pernambuco, Centro de Biociências, Departamento de Micologia, Laboratório de Hifomicetos de Folhedo, Avenida da Engenharia, s/n Cidade Universitária, Recife, PE 50.740-600 Brazil
| | - Tom W. May
- International Commission on the Taxonomy of Fungi, Champaign, IL USA
- Royal Botanic Gardens Victoria, Birdwood Avenue, Melbourne, Victoria 3004 Australia
| | - Wieland Meyer
- Molecular Mycology Research Laboratory, Centre for Infectious Diseases and Microbiology, Faculty of Medicine and Health, Sydney Medical School, Westmead Clinical School, Marie Bashir Institute for Infectious Diseases and Biosecurity, The University of Sydney, Westmead Hospital (Research and Education Network), Westmead Institute for Medical Research, Sydney, NSW Australia
| | - Maarja Öpik
- International Commission on the Taxonomy of Fungi, Champaign, IL USA
- University of Tartu, 40 Lai Street, 51 005 Tartu, Estonia
| | - Vincent Robert
- Department Pharmaceutical Sciences, University of Perugia, Via Borgo 20 Giugno, 74, Perugia, Italy
- Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Marc Stadler
- International Commission on the Taxonomy of Fungi, Champaign, IL USA
- Department Microbial Drugs, Helmholtz Centre for Infection Research, and German Centre for Infection Research (DZIF), partner site Hannover-Braunschweig, Inhoffenstrasse 7, 38124 Braunschweig, Germany
| | - Marco Thines
- International Commission on the Taxonomy of Fungi, Champaign, IL USA
- Institute of Ecology, Evolution and Diversity, Goethe University, Max-von-Laue-Straße 9, 60439 Frankfurt (Main); Senckenberg Biodiversity and Climate Research Centre, Senckenberganlage 25, 60325 Frankfurt (Main), Germany
| | - Duong Vu
- Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - Andrey M. Yurkov
- International Commission on the Taxonomy of Fungi, Champaign, IL USA
- Leibniz Institute DSMZ-German Collection of Microorganisms and Cell Cultures, Braunschweig, Germany
| | - Ning Zhang
- International Commission on the Taxonomy of Fungi, Champaign, IL USA
- Department of Plant Biology, Rutgers University, New Brunswick, NJ 08901 USA
| | - Conrad L. Schoch
- International Commission on the Taxonomy of Fungi, Champaign, IL USA
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, 45 Center Drive, Bethesda, MD 20892 USA
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12
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Heterothallism revealed in the root rot fungi Berkeleyomyces basicola and B. rouxiae. Fungal Biol 2018; 122:1031-1040. [PMID: 30342619 DOI: 10.1016/j.funbio.2018.08.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2018] [Revised: 07/30/2018] [Accepted: 08/10/2018] [Indexed: 11/19/2022]
Abstract
Berkeleyomyces basicola and Berkeleyomyces rouxiae, two sister species previously treated collectively as Thielaviopsis basicola, reside in the Ceratocystidaceae (Microascales, Ascomycota). Both species are important root pathogens of many important agricultural crops and ornamental plants. Although T. basicola has been known for more than 150y, a sexual state has never been found and it has been assumed to be an asexual pathogen. The aim of this study was to determine the mating strategy of the two Berkeleyomyces species. Investigation of the genome sequences of two B. basicola isolates allowed for the complete characterization of the MATlocus, revealing that it has a typical heterothallic mating system with the MAT1-1andMAT1-2 idiomorphs occurring in different isolates. PCR amplification using mating type primers developed in this study, showed that the MAT1-1-1andMAT1-2-1 genes were also present in different isolates of B. rouxiae. Pairing of isolates representing the two mating types of both species,using a variety of techniques failed to produce sexual structures. Although we have found no direct evidence that they reproduce sexually, these fungi are clearly heterothallic with both mating types occurring in some countries suggesting that a cryptic sexual cycle could exist for them.
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13
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Abstract
Approximately 20% of species in the fungal kingdom are only known to reproduce by asexual means despite the many supposed advantages of sexual reproduction. However, in recent years, sexual cycles have been induced in a series of emblematic "asexual" species. We describe how these discoveries were made, building on observations of evidence for sexual potential or "cryptic sexuality" from population genetic analyses; the presence, distribution, and functionality of mating-type genes; genome analyses revealing the presence of genes linked to sexuality; the functionality of sex-related genes; and formation of sex-related developmental structures. We then describe specific studies that led to the discovery of mating and sex in certain Candida, Aspergillus, Penicillium, and Trichoderma species and discuss the implications of sex including the beneficial exploitation of the sexual cycle. We next consider whether there might be any truly asexual fungal species. We suggest that, although rare, imperfect fungi may genuinely be present in nature and that certain human activities, combined with the genetic flexibility that is a hallmark of the fungal kingdom, might favor the evolution of asexuality under certain conditions. Finally, we argue that fungal species should not be thought of as simply asexual or sexual, but rather as being composed of isolates on a continuum of sexual fertility.
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14
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Nieuwenhuis BPS, James TY. The frequency of sex in fungi. Philos Trans R Soc Lond B Biol Sci 2017; 371:rstb.2015.0540. [PMID: 27619703 DOI: 10.1098/rstb.2015.0540] [Citation(s) in RCA: 94] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/15/2016] [Indexed: 12/16/2022] Open
Abstract
Fungi are a diverse group of organisms with a huge variation in reproductive strategy. While almost all species can reproduce sexually, many reproduce asexually most of the time. When sexual reproduction does occur, large variation exists in the amount of in- and out-breeding. While budding yeast is expected to outcross only once every 10 000 generations, other fungi are obligate outcrossers with well-mixed panmictic populations. In this review, we give an overview of the costs and benefits of sexual and asexual reproduction in fungi, and the mechanisms that evolved in fungi to reduce the costs of either mode. The proximate molecular mechanisms potentiating outcrossing and meiosis appear to be present in nearly all fungi, making them of little use for predicting outcrossing rates, but also suggesting the absence of true ancient asexual lineages. We review how population genetic methods can be used to estimate the frequency of sex in fungi and provide empirical data that support a mixed mode of reproduction in many species with rare to frequent sex in between rounds of mitotic reproduction. Finally, we highlight how these estimates might be affected by the fungus-specific mechanisms that evolved to reduce the costs of sexual and asexual reproduction.This article is part of the themed issue 'Weird sex: the underappreciated diversity of sexual reproduction'.
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Affiliation(s)
- Bart P S Nieuwenhuis
- Department of Evolutionary Biology, Uppsala University, Norbyvägen 18D, 752 36 Uppsala, Sweden
| | - Timothy Y James
- Department of Ecology and Evolutionary Biology, University of Michigan, 830 North University, Ann Arbor, MI 48109-1048, USA
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15
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Wuest CE, Harrington TC, Fraedrich SW, Yun HY, Lu SS. Genetic Variation in Native Populations of the Laurel Wilt Pathogen, Raffaelea lauricola, in Taiwan and Japan and the Introduced Population in the United States. PLANT DISEASE 2017; 101:619-628. [PMID: 30677356 DOI: 10.1094/pdis-10-16-1517-re] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Laurel wilt is a vascular wilt disease caused by Raffaelea lauricola, a mycangial symbiont of an ambrosia beetle, Xyleborus glabratus. The fungus and vector are native to Asia but were apparently introduced to the Savannah, GA, area 15 or more years ago. Laurel wilt has caused widespread mortality on redbay (Persea borbonia) and other members of the Lauraceae in the southeastern United States, and the pathogen and vector have spread as far as Texas. Although believed to be a single introduction, there has been no extensive study on genetic variation of R. lauricola populations that would suggest a genetic bottleneck in the United States. Ten isolates of R. lauricola from Japan, 55 from Taiwan, and 125 from the United States were analyzed with microsatellite and 28S rDNA markers, and with primers developed for two mating-type genes. The new primers identified isolates as either MAT1 or MAT2 mating types in roughly equal proportions in Taiwan and Japan, where there was also high genetic diversity within populations based on all the markers, suggesting that these populations may have cryptic sex. Aside from a local population near Savannah and a single isolate in Alabama that had unique microsatellite alleles, the U.S. population was genetically uniform and included only the MAT2 mating type, supporting the single introduction hypothesis. This study suggests the importance of preventing a second introduction of R. lauricola to the United States, which could introduce the opposite mating type and allow for genetic recombination.
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Affiliation(s)
- Caroline E Wuest
- Department of Plant Pathology, Iowa State University, Ames 50011
| | | | | | - Hye-Young Yun
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Korea 08826
| | - Sheng-Shan Lu
- Division of Forest Protection, Taiwan Forestry Research Institute, Taipei 10066, Taiwan
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16
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Del-Prado R, Divakar PK, Lumbsch HT, Crespo AM. Hidden Genetic Diversity in an Asexually Reproducing Lichen Forming Fungal Group. PLoS One 2016; 11:e0161031. [PMID: 27513649 PMCID: PMC4981466 DOI: 10.1371/journal.pone.0161031] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 07/28/2016] [Indexed: 11/19/2022] Open
Abstract
Asexual species with vegetative propagation of both symbiont partners (soredia) in lichens may harbor lower species diversity because they may indeed represent evolutionary dead ends or clones. In this study we aim to critically examine species boundaries in the sorediate lichen forming fungi Parmotrema reticulatum–Parmotrema pseudoreticulatum complex applying coalescent-based approaches and other recently developed DNA-based methods. To this end, we gathered 180 samples from Africa, Asia, Australasia, Europe, North and South America and generated sequences of internal transcribed spacer of nuclear ribosomal DNA (ITS) and DNA replication licensing factor MCM7 (MCM7). The dataset was analysed using different approaches such as traditional phylogeny–maximum likelihood and Bayesian–genetic distances, automatic barcode gap discovery and coalescent-based methods–PTP, GMYC, spedeSTEM and *Beast–in order to test congruence among results. Additionally, the divergence times were also estimated to elucidate diversification events. Delimitations inferred from the different analyses are comparable with only minor differences, and following a conservative approach we propose that the sampled specimens of the P. reticulatum–P. pseudoreticulatum complex belong to at least eight distinct species-level lineages. Seven are currently classified under P. reticulatum and one as P. pseudoreticulatum. In this work we discuss one of only few examples of cryptic species that have so far been found in sorediate reproducing lichen forming fungi. Additionally our estimates suggest a recent origin of the species complex–during the Miocene. Consequently, the wide distribution of several of the cryptic species has to be explained by intercontinental long-distance dispersal events.
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Affiliation(s)
- Ruth Del-Prado
- Departamento de Biología Vegetal II, Facultad de Farmacia, Universidad Complutense, Madrid, Spain
- * E-mail:
| | - Pradeep Kumar Divakar
- Departamento de Biología Vegetal II, Facultad de Farmacia, Universidad Complutense, Madrid, Spain
| | - H. Thorsten Lumbsch
- Science and Education, Field Museum, Chicago, Illinois, United States of America
| | - Ana M. Crespo
- Departamento de Biología Vegetal II, Facultad de Farmacia, Universidad Complutense, Madrid, Spain
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17
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Mating type markers reveal high levels of heterothallism in Leptographium sensu lato. Fungal Biol 2016; 120:538-546. [PMID: 27020155 DOI: 10.1016/j.funbio.2016.01.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 12/23/2015] [Accepted: 01/03/2016] [Indexed: 01/16/2023]
Abstract
Species of Leptographium sensu lato are sap-stain fungi vectored by bark beetles and some species cause or are associated with tree diseases. Sexual states have been reported for more than 30 species in this group and these have been treated in the sexual genus Grosmannia. No sexual state is known for at least 59 additional species and these reside in the genus Leptographium. The discovery of sexual states for species of Leptographium relies mainly on the presence of fruiting bodies on host tissue at the time of isolation and/or intensive laboratory mating studies, which commonly have low levels of success. We developed mating-type markers to study sexual compatibility of species in Leptographium sensu lato. Using these markers, it was possible to identify mating types for 42 species and to determine thallism in many species for the first time. Surprisingly, the results showed that heterothallic and putatively heterothallic species are abundant (39 out of 42 species) in Leptographium sensu lato, and only three species were confirmed to be homothallic. The mating type markers developed in this study will be useful for future studies concerning mating type and sexual compatibility of species in this genus.
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18
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Ashu EE, Xu J. The roles of sexual and asexual reproduction in the origin and dissemination of strains causing fungal infectious disease outbreaks. INFECTION GENETICS AND EVOLUTION 2015; 36:199-209. [PMID: 26394109 DOI: 10.1016/j.meegid.2015.09.019] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Revised: 09/16/2015] [Accepted: 09/18/2015] [Indexed: 12/15/2022]
Abstract
Sexual reproduction commonly refers to the reproductive process in which genomes from two sources are combined into a single cell through mating and then the zygote genomes are partitioned to progeny cells through meiosis. Reproduction in the absence of mating and meiosis is referred to as asexual or clonal reproduction. One major advantage of sexual reproduction is that it generates genetic variation among progeny which may allow for faster adaptation of the population to novel and/or stressful environments. However, adaptation to stressful or new environments can still occur through mutation, in the absence of sex. In this review, we analyzed the relative contributions of sexual and asexual reproduction in the origin and spread of strains causing fungal infectious diseases outbreaks. The necessity of sex and the ability of asexual fungi to initiate outbreaks are discussed. We propose a framework that relates the modes of reproduction to the origin and propagation of fungal disease outbreaks. Our analyses suggest that both sexual and asexual reproduction can play critical roles in the origin of outbreak strains and that the rapid spread of outbreak strains is often accomplished through asexual expansion.
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Affiliation(s)
- Eta Ebasi Ashu
- Department of Biology, McMaster University, 1280 Main St. W, Hamilton, ON L8S 4K1, Canada
| | - Jianping Xu
- Department of Biology, McMaster University, 1280 Main St. W, Hamilton, ON L8S 4K1, Canada.
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19
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Diversity and movement of indoor Alternaria alternata across the mainland USA. Fungal Genet Biol 2015; 81:62-72. [PMID: 26004989 DOI: 10.1016/j.fgb.2015.05.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2015] [Revised: 04/21/2015] [Accepted: 05/07/2015] [Indexed: 01/11/2023]
Abstract
Alternaria spp. from sect. Alternaria are frequently associated with hypersensitivity pneumonitis, asthma and allergic fungal rhinitis and sinusitis. Since Alternaria is omnipresent in the outdoor environment, it is thought that the indoor spore concentration is mainly influenced by the outdoor spore concentration. However, few studies have investigated indoor Alternaria isolates, or attempted a phylogeographic or population genetic approach to investigate their movement. Therefore, the aim of the current study was to investigate the molecular diversity of indoor Alternaria isolates in the USA, and to test for recombination, using these approaches. Alternaria isolates collected throughout the USA were identified using ITS, gapdh and endoPG gene sequencing. This was followed by genotyping and population genetic inference of isolates belonging to Alternaria sect. Alternaria together with 37 reference isolates, using five microsatellite markers. Phylogenetic analyses revealed that species of Alternaria sect. Alternaria represented 98% (153 isolates) of the indoor isolates collected throughout the USA, of which 137 isolates could be assigned to A. alternata, 15 to the A. arborescens species complex and a single isolate to A. burnsii. The remaining 2% (3 isolates) represented sect. Infectoriae (single isolate) and sect. Pseudoulocladium (2 isolates). Population assignment analyses of the 137 A. alternata isolates suggested that subpopulations did not exist within the sample. The A. alternata isolates were thus divided into four artificial subpopulations to represent four quadrants of the USA. Forty-four isolates representing the south-western quadrant displayed the highest level of uniqueness based on private alleles, while the highest level of gene flow was detected between the south-eastern (32 isolates) and south-western quadrants. Genotypic diversity was high for all quadrants, and a test for linkage disequilibrium suggested that A. alternata has a cryptic sexual cycle. These statistics could be correlated with environmental factors, suggesting that indoor A. alternata isolates, although extremely diverse, have a continental distribution and high levels of gene flow over the continent.
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20
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Yáñez-Carrillo P, Robledo-Márquez KA, Ramírez-Zavaleta CY, De Las Peñas A, Castaño I. The mating type-like loci of Candida glabrata. Rev Iberoam Micol 2014; 31:30-4. [DOI: 10.1016/j.riam.2013.09.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 09/27/2013] [Indexed: 10/26/2022] Open
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21
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Mating type genes and cryptic sexuality as tools for genetically manipulating industrial molds. Appl Microbiol Biotechnol 2013; 97:9609-20. [DOI: 10.1007/s00253-013-5268-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 09/12/2013] [Accepted: 09/14/2013] [Indexed: 01/11/2023]
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22
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Duong TA, de Beer ZW, Wingfield BD, Wingfield MJ. Characterization of the mating-type genes in Leptographium procerum and Leptographium profanum. Fungal Biol 2013; 117:411-21. [PMID: 23809651 DOI: 10.1016/j.funbio.2013.04.005] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Revised: 04/11/2013] [Accepted: 04/12/2013] [Indexed: 11/20/2022]
Abstract
Leptographium procerum and the closely related species Leptographium profanum, are ascomycetes associated with root-infesting beetles on pines and hardwood trees, respectively. Both species occur in North America where they are apparently native. L. procerum has also been found in Europe, China New Zealand, and South Africa where it has most probably been introduced. As is true for many other Leptographium species, sexual states have never been observed in L. procerum or L. profanum. The objectives of this study were to clone and characterize the mating type loci of these fungi, and to develop markers to determine the mating types of individual isolates. To achieve this, a partial sequence of MAT1-2-1 was amplified using degenerate primers targeting the high mobility group (HMG) sequence. A complete MAT1-2 idiomorph of L. profanum was subsequently obtained by screening a genomic library using the HMG sequence as a probe. Long range PCR was used to amplify the complete MAT1-1 idiomorph of L. profanum and both the MAT1-1 and MAT1-2 idiomorphs of L. procerum. Characterization of the MAT idiomorphs suggests that the MAT genes are fully functional and that individuals of both these species are self-sterile in nature with a heterothallic mating system. Mating type markers were developed and tested on a population of L. procerum isolates from the USA, the assumed center of origin for this species. The results suggest that cryptic sexual reproduction is occurring or has recently taken place within this population.
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Affiliation(s)
- Tuan A Duong
- Department of Genetics, Forestry and Agricultural Biotechnology Institute-FABI, University of Pretoria, Pretoria 0002, South Africa.
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23
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Sexual reproduction and mating-type-mediated strain development in the penicillin-producing fungus Penicillium chrysogenum. Proc Natl Acad Sci U S A 2013; 110:1476-81. [PMID: 23307807 DOI: 10.1073/pnas.1217943110] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Penicillium chrysogenum is a filamentous fungus of major medical and historical importance, being the original and present-day industrial source of the antibiotic penicillin. The species has been considered asexual for more than 100 y, and despite concerted efforts, it has not been possible to induce sexual reproduction, which has prevented sexual crosses being used for strain improvement. However, using knowledge of mating-type (MAT) gene organization, we now describe conditions under which a sexual cycle can be induced leading to production of meiotic ascospores. Evidence of recombination was obtained using both molecular and phenotypic markers. The identified heterothallic sexual cycle was used for strain development purposes, generating offspring with novel combinations of traits relevant to penicillin production. Furthermore, the MAT1-1-1 mating-type gene, known primarily for a role in governing sexual identity, was also found to control transcription of a wide range of genes with biotechnological relevance including those regulating penicillin production, hyphal morphology, and conidial formation. These discoveries of a sexual cycle and MAT gene function are likely to be of broad relevance for manipulation of other asexual fungi of economic importance.
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24
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Singh G, Dal Grande F, Cornejo C, Schmitt I, Scheidegger C. Genetic basis of self-incompatibility in the lichen-forming fungus Lobaria pulmonaria and skewed frequency distribution of mating-type idiomorphs: implications for conservation. PLoS One 2012; 7:e51402. [PMID: 23236495 PMCID: PMC3517546 DOI: 10.1371/journal.pone.0051402] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Accepted: 11/02/2012] [Indexed: 12/14/2022] Open
Abstract
Fungal populations that reproduce sexually are likely to be genetically more diverse and have a higher adaptive potential than asexually reproducing populations. Mating systems of fungal species can be self-incompatible, requiring the presence of isolates of different mating-type genes for sexual reproduction to occur, or self-compatible, requiring only one. Understanding the distribution of mating-type genes in populations can help to assess the potential of self-incompatible species to reproduce sexually. In the locally threatened epiphytic lichen-forming fungus Lobaria pulmonaria (L.) Hoffm., low frequency of sexual reproduction is likely to limit the potential of populations to adapt to changing environmental conditions. Our study provides direct evidence of self-incompatibility (heterothallism) in L. pulmonaria. It can thus be hypothesized that sexual reproduction in small populations might be limited by an unbalanced distribution of mating-type genes. We therefore assessed neutral genetic diversity (using microsatellites) and mating-type ratio in 27 lichen populations (933 individuals). We found significant differences in the frequency of the two mating types in 13 populations, indicating a lower likelihood of sexual reproduction in these populations. This suggests that conservation translocation activities aiming at maximizing genetic heterogeneity in threatened and declining populations should take into account not only presence of fruiting bodies in transplanted individuals, but also the identity and balanced representation of mating-type genes.
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Affiliation(s)
- Garima Singh
- Biodiversity and Conservation Biology, WSL Swiss Federal Research Institute, Birmensdorf, Switzerland
| | - Francesco Dal Grande
- Biodiversity and Conservation Biology, WSL Swiss Federal Research Institute, Birmensdorf, Switzerland
- Biodiversity and Climate Research Centre (BiK-F), Senckenberg Gesellschaft für Naturforschung, Frankfurt am Main, Germany
| | - Carolina Cornejo
- Biodiversity and Conservation Biology, WSL Swiss Federal Research Institute, Birmensdorf, Switzerland
| | - Imke Schmitt
- Biodiversity and Climate Research Centre (BiK-F), Senckenberg Gesellschaft für Naturforschung, Frankfurt am Main, Germany
- Institute of Ecology, Evolution and Diversity, Goethe Universität, Frankfurt, Germany
| | - Christoph Scheidegger
- Biodiversity and Conservation Biology, WSL Swiss Federal Research Institute, Birmensdorf, Switzerland
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25
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Abstract
The arbuscular mycorrhizal fungi (AMF) are important symbionts of land plants, which are known for their tremendous positive effects on terrestrial ecosystems, their peculiar cellular features, and their very old evolutionary history. To date, no sexual stage or apparatus have ever been observed in these organisms; a remarkable absence for a eukaryotic lineage. For this reason, AMF have long been considered an evolutionary oddity, having evolved for over 500 millions of years in the absence of sexual reproduction and meiosis. Here, we discuss the recent identification across a number of AMF genomes, of many genes that are known to be involved in the process of meiosis in several eukaryotic model species. The presence of these genes in AMF is a previously unsuspected and highly intriguing finding, which suggests the presence of a “hidden” sexual (or parasexual) reproduction that awaits formal observation in these poorly studied fungi.
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Affiliation(s)
- Nicolas Corradi
- Canadian Institute for Advanced Research; Department of Biology; University of Ottawa; Ottawa, ON Canada
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26
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Asexual reproduction induces a rapid and permanent loss of sexual reproduction capacity in the rice fungal pathogen Magnaporthe oryzae: results of in vitro experimental evolution assays. BMC Evol Biol 2012; 12:42. [PMID: 22458778 PMCID: PMC3379926 DOI: 10.1186/1471-2148-12-42] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Accepted: 03/29/2012] [Indexed: 12/15/2022] Open
Abstract
Background Sexual reproduction is common in eukaryotic microorganisms, with few species reproducing exclusively asexually. However, in some organisms, such as fungi, asexual reproduction alternates with episodic sexual reproduction events. Fungi are thus appropriate organisms for studies of the reasons for the selection of sexuality or clonality and of the mechanisms underlying this selection. Magnaporthe oryzae, an Ascomycete causing blast disease on rice, reproduces mostly asexually in natura. Sexual reproduction is possible in vitro and requires (i) two strains of opposite mating types including (ii) at least one female-fertile strain (i.e. a strain able to produce perithecia, the female organs in which meiosis occurs). Female-fertile strains are found only in limited areas of Asia, in which evidence for contemporary recombination has recently been obtained. We induced the forced evolution of four Chinese female-fertile strains in vitro by the weekly transfer of asexual spores (conidia) between Petri dishes. We aimed to determine whether female fertility was rapidly lost in the absence of sexual reproduction and whether this loss was controlled genetically or epigenetically. Results All the strains became female-sterile after 10 to 19 rounds of selection under asexual conditions. As no single-spore isolation was carried out, the observed decrease in the production of perithecia reflected the emergence and the invasion of female-sterile mutants. The female-sterile phenotype segregated in the offspring of crosses between female-sterile evolved strains and female-fertile wild-type strains. This segregation was maintained in the second generation in backcrosses. Female-sterile evolved strains were subjected to several stresses, but none induced the restoration of female fertility. This loss of fertility was therefore probably due to genetic rather than epigenetic mechanisms. In competition experiments, female-sterile mutants produced similar numbers of viable conidia to wild-type strains, but released them more efficiently. This advantage may account for the invasion of our populations by female-sterile mutants. Conclusions We show for the first time that, in the absence of sexual reproduction, female-sterile mutants of M. oryzae rice strains can arise and increase in abundance in asexual generations. This change in phenotype was frequent and probably caused by mutation. These results suggest that female fertility may have been lost rapidly during the dispersion of the fungus from Asia to the rest of the world.
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Irzykowska L, Bocianowski J, Waśkiewicz A, Weber Z, Karolewski Z, Goliński P, Kostecki M, Irzykowski W. Genetic variation of Fusarium oxysporum isolates forming fumonisin B(1) and moniliformin. J Appl Genet 2012; 53:237-47. [PMID: 22367665 PMCID: PMC3334483 DOI: 10.1007/s13353-012-0087-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 01/21/2012] [Accepted: 01/27/2012] [Indexed: 10/28/2022]
Abstract
Thirty single-spore isolates of a toxigenic fungus, Fusarium oxysporum, were isolated from asparagus spears and identified by species-specific polymerase chain reaction (PCR) and translation elongation factor 1-α (TEF) sequence analysis. In the examined sets of F. oxysporum isolates, the DNA sequences of mating type genes (MAT) were identified. The distribution of MAT idiomorph may suggest that MAT1-2 is a predominant mating type in the F. oxysporum population. F. oxysporum is mainly recognised as a producer of moniliformin-the highly toxic secondary metabolite. Moniliformin content was determined by high-performance liquid chromatography (HPLC) analysis in the range 0.05-1,007.47 μg g(-1) (mean 115.93 μg g(-1)) but, also, fumonisin B(1) was detected, in the concentration range 0.01-0.91 μg g(-1) (mean 0.19 μg g(-1)). There was no association between mating types and the mycotoxins biosynthesis level. Additionally, a significant intra-species genetic diversity was revealed and molecular markers associated with toxins biosynthesis were identified.
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Affiliation(s)
- Lidia Irzykowska
- Department of Phytopathology, Poznan University of Life Sciences, Dąbrowskiego 159, 60-594 Poznań, Polan.
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Presence and functionality of mating type genes in the supposedly asexual filamentous fungus Aspergillus oryzae. Appl Environ Microbiol 2012; 78:2819-29. [PMID: 22327593 DOI: 10.1128/aem.07034-11] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The potential for sexual reproduction in Aspergillus oryzae was assessed by investigating the presence and functionality of MAT genes. Previous genome studies had identified a MAT1-1 gene in the reference strain RIB40. We now report the existence of a complementary MAT1-2 gene and the sequencing of an idiomorphic region from A. oryzae strain AO6. This allowed the development of a PCR diagnostic assay, which detected isolates of the MAT1-1 and MAT1-2 genotypes among 180 strains assayed, including industrial tane-koji isolates. Strains used for sake and miso production showed a near-1:1 ratio of the MAT1-1 and MAT1-2 mating types, whereas strains used for soy sauce production showed a significant bias toward the MAT1-2 mating type. MAT1-1 and MAT1-2 isogenic strains were then created by genetic manipulation of the resident idiomorph, and gene expression was compared by DNA microarray and quantitative real-time PCR (qRT-PCR) methodologies under conditions in which MAT genes were expressed. Thirty-three genes were found to be upregulated more than 10-fold in either the MAT1-1 host strain or the MAT1-2 gene replacement strain relative to each other, showing that both the MAT1-1 and MAT1-2 genes functionally regulate gene expression in A. oryzae in a mating type-dependent manner, the first such report for a supposedly asexual fungus. MAT1-1 expression specifically upregulated an α-pheromone precursor gene, but the functions of most of the genes affected were unknown. The results are consistent with a heterothallic breeding system in A. oryzae, and prospects for the discovery of a sexual cycle are discussed.
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A fungal sexual revolution: Aspergillus and Penicillium show the way. Curr Opin Microbiol 2011; 14:649-54. [DOI: 10.1016/j.mib.2011.10.001] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Revised: 09/29/2011] [Accepted: 10/03/2011] [Indexed: 01/09/2023]
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Dyer PS, O'Gorman CM. Sexual development and cryptic sexuality in fungi: insights from Aspergillus species. FEMS Microbiol Rev 2011; 36:165-92. [PMID: 22091779 DOI: 10.1111/j.1574-6976.2011.00308.x] [Citation(s) in RCA: 160] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Accepted: 09/04/2011] [Indexed: 11/30/2022] Open
Abstract
Major insights into sexual development and cryptic sexuality within filamentous fungi have been gained from investigations using Aspergillus species. Here, an overview is first given into sexual morphogenesis in the aspergilli, describing the different types of sexual structures formed and how their production is influenced by a variety of environmental and nutritional factors. It is argued that the formation of cleistothecia and accessory tissues, such as Hülle cells and sclerotia, should be viewed as two independent but co-ordinated developmental pathways. Next, a comprehensive survey of over 75 genes associated with sexual reproduction in the aspergilli is presented, including genes relating to mating and the development of cleistothecia, sclerotia and ascospores. Most of these genes have been identified from studies involving the homothallic Aspergillus nidulans, but an increasing number of studies have now in addition characterized 'sex-related' genes from the heterothallic species Aspergillus fumigatus and Aspergillus flavus. A schematic developmental genetic network is proposed showing the inter-relatedness between these genes. Finally, the discovery of sexual reproduction in certain Aspergillus species that were formerly considered to be strictly asexual is reviewed, and the importance of these findings for cryptic sexuality in the aspergilli as a whole is discussed.
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Affiliation(s)
- Paul S Dyer
- School of Biology, University of Nottingham, Nottingham, UK.
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Zaffarano PL, Queloz V, Duò A, Grünig CR. Sex in the PAC: a hidden affair in dark septate endophytes? BMC Evol Biol 2011; 11:282. [PMID: 21961933 PMCID: PMC3199270 DOI: 10.1186/1471-2148-11-282] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2011] [Accepted: 09/30/2011] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Fungi are asexually and sexually reproducing organisms that can combine the evolutionary advantages of the two reproductive modes. However, for many fungi the sexual cycle has never been observed in the field or in vitro and it remains unclear whether sexual reproduction is absent or cryptic. Nevertheless, there are indirect approaches to assess the occurrence of sex in a species, such as population studies, expression analysis of genes involved in mating processes and analysis of their selective constraints. The members of the Phialocephala fortinii s. l. - Acephala applanata species complex (PAC) are ascomycetes and the predominant dark septate endophytes that colonize woody plant roots. Despite their abundance in many ecosystems of the northern hemisphere, no sexual state has been identified to date and little is known about their reproductive biology, and how it shaped their evolutionary history and contributes to their ecological role in forest ecosystems. We therefore aimed at assessing the importance of sexual reproduction by indirect approaches that included molecular analyses of the mating type (MAT) genes involved in reproductive processes. RESULTS The study included 19 PAC species and > 3, 000 strains that represented populations from different hosts, continents and ecosystems. Whereas A. applanata had a homothallic (self-fertile) MAT locus structure, all other species were structurally heterothallic (self-sterile). Compatible mating types were observed to co-occur more frequently than expected by chance. Moreover, in > 80% of the populations a 1:1 mating type ratio and gametic equilibrium were found. MAT genes were shown to evolve under strong purifying selection. CONCLUSIONS The signature of sex was found in worldwide populations of PAC species and functionality of MAT genes is likely preserved by purifying selection. We hypothesize that cryptic sex regularely occurs in the PAC and that further field studies and in vitro crosses will lead to the discovery of the sexual state. Although structurally heterothallic species prevail, it cannot be excluded that homothallism represents the ancestral breeding system in the PAC.
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Affiliation(s)
- Pascal L Zaffarano
- Institute of Integrative Biology (IBZ), Forest Pathology and Dendrology, ETH Zurich, 8092 Zürich, Switzerland
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Abstract
Sexual reproduction enables genetic exchange in eukaryotic organisms as diverse as fungi, animals, plants, and ciliates. Given its ubiquity, sex is thought to have evolved once, possibly concomitant with or shortly after the origin of eukaryotic organisms themselves. The basic principles of sex are conserved, including ploidy changes, the formation of gametes via meiosis, mate recognition, and cell-cell fusion leading to the production of a zygote. Although the basic tenants are shared, sex determination and sexual reproduction occur in myriad forms throughout nature, including outbreeding systems with more than two mating types or sexes, unisexual selfing, and even examples in which organisms switch mating type. As robust and diverse genetic models, fungi provide insights into the molecular nature of sex, sexual specification, and evolution to advance our understanding of sexual reproduction and its impact throughout the eukaryotic tree of life.
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Affiliation(s)
- Min Ni
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina 27710, USA.
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Fávaro LCDL, de Melo FL, Aguilar-Vildoso CI, Araújo WL. Polyphasic analysis of intraspecific diversity in Epicoccum nigrum warrants reclassification into separate species. PLoS One 2011; 6:e14828. [PMID: 21853017 PMCID: PMC3154903 DOI: 10.1371/journal.pone.0014828] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Accepted: 12/15/2010] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Epicoccum nigrum Link (syn. E. purpurascens Ehrenb. ex Schlecht) is a saprophytic ascomycete distributed worldwide which colonizes a myriad of substrates. This fungus has been known as a biological control agent for plant pathogens and produces a variety of secondary metabolites with important biological activities as well as biotechnological application. E. nigrum produces darkly pigmented muriform conidia on short conidiophores on sporodochia and is a genotypically and phenotypically highly variable species. Since different isolates identified as E. nigrum have been evaluated as biological control agents and used for biocompound production, it is highly desirable that this species name refers to only one lineage. However, according to morphological and genetic variation, E. nigrum present two genotypes that may comprise more than one species. METHODOLOGY/PRINCIPAL FINDINGS We report the application of combined molecular (ITS and β-tubulin gene sequence analysis, PCR-RFLP and AFLP techniques), morphometric, physiological, genetic compatibility and recombination analysis to study the taxonomic relationships within an endophytic population that has been identified as E. nigrum. This combined analysis established two genotypes showing morphological, physiological and genetic divergence as well as genetic incompatibility characterized by colony inhibition, strongly indicating that these genotypes correspond to different species. Genotype 1 corresponds to E. nigrum while genotype 2 represents a new species, referred to in this study as Epicoccum sp. CONCLUSIONS/SIGNIFICANCE This research contributes to the knowledge of the Epicoccum genus and asserts that the classification of E. nigrum as a single variable species should be reassessed. In fact, based on the polyphasic approach we suggest the occurrence of cryptic species within E. nigrum and also that many of the sequences deposited as E. nigrum in GenBank and culture collection of microbial strains should be reclassified, including the reference strain CBS 161.73 sequenced in this work. In addition, this study provides valuable tools for differentiation of Epicoccum species.
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Affiliation(s)
| | | | | | - Welington Luiz Araújo
- Laboratory of Molecular Biology and Microbial Ecology, NIB, University of Mogi das Cruzes, Mogi das Cruzes, São Paulo, Brazil
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Pöggeler S, O’Gorman CM, Hoff B, Kück U. Molecular organization of the mating-type loci in the homothallic Ascomycete Eupenicillium crustaceum. Fungal Biol 2011; 115:615-24. [DOI: 10.1016/j.funbio.2011.03.003] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Revised: 02/25/2011] [Accepted: 03/03/2011] [Indexed: 10/18/2022]
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Zhang S, Zhang YJ, Liu XZ, Wen HA, Wang M, Liu DS. Cloning and analysis of the MAT1-2-1 gene from the traditional Chinese medicinal fungus Ophiocordyceps sinensis. Fungal Biol 2011; 115:708-14. [PMID: 21802050 DOI: 10.1016/j.funbio.2011.05.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Revised: 05/09/2011] [Accepted: 05/18/2011] [Indexed: 10/18/2022]
Abstract
The entomopathogenic fungus Ophiocordyceps sinensis has been important in traditional Chinese medicine but has yet to be commercially cultivated. One bottleneck is the very low frequency of stromata formation from artificially infected moth larvae. The mating system of fungi is the determining factor for sexual reproduction, but mating-type genes of O. sinensis have not been previously investigated. In this study, the putative mating-type gene MAT1-2-1 within the MAT1-2 idiomorph was amplified by polymerase chain reaction (PCR) and was determined to consist of 859 nucleotides that encode 249 amino acids; genes within the MAT1-1 idiomorph, however, were not determined. The MAT1-2-1 gene contained the conserved high-mobility group (HMG) box, and MAT1-2-1 flanking sequences were subsequently obtained. Although no putative open reading frames of the MAT1-1 idiomorph were detected within the ca. 8-kb flanking sequences of MAT1-2-1, a putative DNA lyase gene (which is present next to both idiomorphs in some heterothallic fungi) was found ca. 3.0 kb downstream of MAT1-2-1. The intervening distance between MAT1-2-1 and the DNA lyase gene in O. sinensis is larger than that in Cordyceps militaris and Cordyceps takaomontana. In addition, O. sinensis showed low sequence similarities with C. militaris and C. takaomontana in both MAT1-2-1 and the DNA lyase gene. In the phylogenetic tree, different MAT1-2-1 haplotypes of O. sinensis clustered together with high bootstrap support. As a single-copy gene, MAT1-2-1 was detected in all examined O. sinensis isolates including tissue cultures and single-ascospore cultures. This report describes, for the first time, a mating-type gene of O. sinensis.
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Affiliation(s)
- Shu Zhang
- Institute of Applied Chemistry, Shanxi University, Taiyuan 030006, China
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Conserved regulators of mating are essential for Aspergillus fumigatus cleistothecium formation. EUKARYOTIC CELL 2010; 9:774-83. [PMID: 20348388 DOI: 10.1128/ec.00375-09] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Sexual reproduction of the human pathogen Aspergillus fumigatus (teleomorph: Neosartorya fumigata) was assumed to be absent or cryptic until recently, when fertile crosses among geographically restricted environmental isolates were described. Here, we provide evidence for mating, fruiting body development, and ascosporogenesis accompanied by genetic recombination between unrelated, clinical isolates of A. fumigatus, and this evidence demonstrates the generality and reproducibility of this long-time-undisclosed phase in the life cycle of this heterothallic fungus. Successful mating requires the presence of both mating-type idiomorphs MAT1-1 and MAT1-2, as does expression of genes encoding factors presumably involved in this process. Moreover, analysis of an A. fumigatus mutant deleted for the nsdD gene suggests a role of this conserved regulator of cleistothecium development in hyphal fusion and hence heterokaryon formation.
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