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Munna MMR, Islam MA, Shanta SS, Monty MA. Structural, functional, molecular docking analysis of a hypothetical protein from Talaromyces marneffei and its molecular dynamic simulation: an in-silico approach. J Biomol Struct Dyn 2024:1-20. [PMID: 38345137 DOI: 10.1080/07391102.2024.2314264] [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: 07/31/2023] [Accepted: 01/29/2024] [Indexed: 03/01/2024]
Abstract
Telaromyces marneffei (formerly Penicillium marneffei) is an endemic pathogenic fungus in Southern China and Southeast Asia. It can cause disease in patients with travel-related exposure to this organism and high morbidity and mortality in acquired immune deficiency syndrome (AIDS). In this study, we analyzed the structure and function of a hypothetical protein from T. marneffei using several bioinformatics tools and servers to unveil novel pharmacological targets and design a peptide vaccine against specific epitopes. A total of seven functional epitopes were screened on the protein, and 'STGVDMWSV' was the most antigenic, non-allergenic and non-toxic. Molecular docking showed stronger affinity between the CTL epitope 'STGVDMWSV' and the MHC I allele HLA-A*02:01, a higher docking score -234.98 kcal/mol, revealed stable interactions during a 100 ns molecular dynamic simulation. Overall, the results of this study revealed that this hypothetical protein is crucial for comprehending biochemical, physiological pathways and identifying novel therapeutic targets for human health. Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Md Masudur Rahman Munna
- Department of Biotechnology and Genetic Engineering, Bangabandhu Sheikh Mujibur Rahman Science and Technology University, Gopalganj, Bangladesh
| | - Md Ariful Islam
- School of Pharmacy, Shanghai Jiao Tong University, Shanghai, PR China
| | - Saima Sajnin Shanta
- Department of Biochemistry and Molecular Biology, Bangabandhu Sheikh Mujibur Rahman Science and Technology University, Gopalganj, Bangladesh
| | - Masuma Akter Monty
- Institute of Biomedical Engineering and Technology, Shanghai Engineering Research Center of Molecular Therapeutics and New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, PR China
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2
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Wang F, Han R, Chen S. An Overlooked and Underrated Endemic Mycosis-Talaromycosis and the Pathogenic Fungus Talaromyces marneffei. Clin Microbiol Rev 2023; 36:e0005122. [PMID: 36648228 PMCID: PMC10035316 DOI: 10.1128/cmr.00051-22] [Citation(s) in RCA: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Talaromycosis is an invasive mycosis endemic in tropical and subtropical Asia and is caused by the pathogenic fungus Talaromyces marneffei. Approximately 17,300 cases of T. marneffei infection are diagnosed annually, and the reported mortality rate is extremely high (~1/3). Despite the devastating impact of talaromycosis on immunocompromised individuals, particularly HIV-positive persons, and the increase in reported occurrences in HIV-uninfected persons, diagnostic and therapeutic approaches for talaromycosis have received far too little attention worldwide. In 2021, scientists living in countries where talaromycosis is endemic raised a global demand for it to be recognized as a neglected tropical disease. Therefore, T. marneffei and the infectious disease induced by this fungus must be treated with concern. T. marneffei is a thermally dimorphic saprophytic fungus with a complicated mycological growth process that may produce various cell types in its life cycle, including conidia, hyphae, and yeast, all of which are associated with its pathogenicity. However, understanding of the pathogenic mechanism of T. marneffei has been limited until recently. To achieve a holistic view of T. marneffei and talaromycosis, the current knowledge about talaromycosis and research breakthroughs regarding T. marneffei growth biology are discussed in this review, along with the interaction of the fungus with environmental stimuli and the host immune response to fungal infection. Importantly, the future research directions required for understanding this serious infection and its causative pathogenic fungus are also emphasized to identify solutions that will alleviate the suffering of susceptible individuals worldwide.
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Affiliation(s)
- Fang Wang
- Intensive Care Unit, Biomedical Research Center, Shenzhen Institute of Translational Medicine, Health Science Center, The First Affiliated Hospital of Shenzhen University, Shenzhen Second People’s Hospital, Shenzhen, China
| | - RunHua Han
- Department of Chemistry, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Shi Chen
- Intensive Care Unit, Biomedical Research Center, Shenzhen Institute of Translational Medicine, Health Science Center, The First Affiliated Hospital of Shenzhen University, Shenzhen Second People’s Hospital, Shenzhen, China
- Department of Burn and Plastic Surgery, Biomedical Research Center, Shenzhen Institute of Translational Medicine, Health Science Center, The First Affiliated Hospital of Shenzhen University, Shenzhen Second People’s Hospital, Shenzhen, China
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3
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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; 10:573. [PMID: 35336148 PMCID: PMC8954384 DOI: 10.3390/microorganisms10030573] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [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
| | - 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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Wilson AM, Wilken PM, Wingfield MJ, Wingfield BD. Genetic Networks That Govern Sexual Reproduction in the Pezizomycotina. Microbiol Mol Biol Rev 2021; 85:e0002021. [PMID: 34585983 PMCID: PMC8485983 DOI: 10.1128/mmbr.00020-21] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Sexual development in filamentous fungi is a complex process that relies on the precise control of and interaction between a variety of genetic networks and pathways. The mating-type (MAT) genes are the master regulators of this process and typically act as transcription factors, which control the expression of genes involved at all stages of the sexual cycle. In many fungi, the sexual cycle typically begins when the mating pheromones of one mating type are recognized by a compatible partner, followed by physical interaction and fertilization. Subsequently, highly specialized sexual structures are formed, within which the sexual spores develop after rounds of meiosis and mitosis. These spores are then released and germinate, forming new individuals that initiate new cycles of growth. This review provides an overview of the known genetic networks and pathways that are involved in each major stage of the sexual cycle in filamentous ascomycete fungi.
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Affiliation(s)
- Andi M. Wilson
- Forestry and Agricultural Biotechnology Institute, Department of Biochemistry, Genetics, and Microbiology, University of Pretoria, Pretoria, Gauteng, South Africa
| | - P. Markus Wilken
- Forestry and Agricultural Biotechnology Institute, Department of Biochemistry, Genetics, and Microbiology, University of Pretoria, Pretoria, Gauteng, South Africa
| | - Michael J. Wingfield
- Forestry and Agricultural Biotechnology Institute, Department of Biochemistry, Genetics, and Microbiology, University of Pretoria, Pretoria, Gauteng, South Africa
| | - Brenda D. Wingfield
- Forestry and Agricultural Biotechnology Institute, Department of Biochemistry, Genetics, and Microbiology, University of Pretoria, Pretoria, Gauteng, South Africa
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Cen J, Chen J, Qiu Y, Zeng W, Zhang J. Bioinformatic analysis of the pathogenic mechanism of talaromyces marneffei infection. Medicine (Baltimore) 2020; 99:e23409. [PMID: 33235120 PMCID: PMC7710178 DOI: 10.1097/md.0000000000023409] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Talaromyces marneffei (T marneffei), known as a significant pathogen in patients with AIDS in Southeast Asia, is a dimorphic fungus, which can cause deadly systematic infection in immunocompromised hosts. What is more, the dimorphic phase transition has been reported as a conspicuous process linked with virulence. Interestingly, the yeast form was found in infected individuals, representing the pathogenic phase. However, few researches were found to study the mechanism of dimorphic transition. Thus, a diverse insight into the dimorphic switch mechanism, is urgently needed and we are the first one to research the mechanism of dimorphism. METHODS Firstly, we investigated the microarray of T. marneffei in the Gene Expression Omnibus database (GEO) for differentially expressed genes (DEGs). Then Database for Annotation, Visualization and Integrated Discovery (DAVID) v6.8 was employed to analyze the underlying enrichment and pathway in biological process of DEGs. Meanwhile, protein-protein interaction (PPI) network was constructed using STRING database. On the strength of the theory that similar amino acid sequences share similar structures, which play a decisive role on the function of protein, three dimensional structures of hub-genes were predicted to further investigate the likely function of hub-genes. RESULTS GSE51109 was elected as the eligible series for the purpose of our research, including GSM1238923 (GSM23), GSM1238924 (GSM24), and GSM1238925 (GSM25). PMAA_012920, PMAA_028730, PMAA_068140, PMAA_092900, PMAA_032350 were the most remarkable genes in all of the three PPI networks, thus, were viewed as hub-genes. With regard to the three-dimensional construction, except that there was no significant prediction structure of PMAA_092900 with the criterion seq identify > 30%, GMQE: 0-1, QMEAN4: -4-0, the parallel templates for four structures were Crystal structure of Saccharomyces cerevesiae mitochondrial NADP(+)-dependent isocitrate dehydrogenase in complex with isocitrate, Organellar two-pore channels (TPCs), Yeast Isocitrate Dehydrogenase (Apo Form) and Crystal Structure Of ATP-Dependent Phosphoenolpyruvate Carboxykinase From Thermus thermophilus HB8 in order. CONCLUSION The dimorphic transition of T. marneffei was viewed as a pathogenic factor and DEGs were observed. In-depth study of the function and pathway of DEGs revealed that PMAA_012920, PMAA_028730, PMAA_068140, PMAA_092900, PMAA_032350 were most likely acting as the hub-genes and were likely taking effect through regulating energy metabolism.
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Affiliation(s)
- Jiemei Cen
- Department of Respiratory Medicine, the Eighth Affiliated Hospital, Sun Yat-sen University, Shenzhen, Guangdong
- Department of Respiratory Medicine
| | - Jiarui Chen
- Spine and Osteopathy Ward, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Ye Qiu
- Department of Respiratory Medicine
| | - Wen Zeng
- Department of Respiratory Medicine
| | - Jianquan Zhang
- Department of Respiratory Medicine, the Eighth Affiliated Hospital, Sun Yat-sen University, Shenzhen, Guangdong
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Houbraken J, Kocsubé S, Visagie C, Yilmaz N, Wang XC, Meijer M, Kraak B, Hubka V, Bensch K, Samson R, Frisvad J. Classification of Aspergillus, Penicillium, Talaromyces and related genera ( Eurotiales): An overview of families, genera, subgenera, sections, series and species. Stud Mycol 2020; 95:5-169. [PMID: 32855739 PMCID: PMC7426331 DOI: 10.1016/j.simyco.2020.05.002] [Citation(s) in RCA: 264] [Impact Index Per Article: 66.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The Eurotiales is a relatively large order of Ascomycetes with members frequently having positive and negative impact on human activities. Species within this order gain attention from various research fields such as food, indoor and medical mycology and biotechnology. In this article we give an overview of families and genera present in the Eurotiales and introduce an updated subgeneric, sectional and series classification for Aspergillus and Penicillium. Finally, a comprehensive list of accepted species in the Eurotiales is given. The classification of the Eurotiales at family and genus level is traditionally based on phenotypic characters, and this classification has since been challenged using sequence-based approaches. Here, we re-evaluated the relationships between families and genera of the Eurotiales using a nine-gene sequence dataset. Based on this analysis, the new family Penicillaginaceae is introduced and four known families are accepted: Aspergillaceae, Elaphomycetaceae, Thermoascaceae and Trichocomaceae. The Eurotiales includes 28 genera: 15 genera are accommodated in the Aspergillaceae (Aspergillago, Aspergillus, Evansstolkia, Hamigera, Leiothecium, Monascus, Penicilliopsis, Penicillium, Phialomyces, Pseudohamigera, Pseudopenicillium, Sclerocleista, Warcupiella, Xerochrysium and Xeromyces), eight in the Trichocomaceae (Acidotalaromyces, Ascospirella, Dendrosphaera, Rasamsonia, Sagenomella, Talaromyces, Thermomyces, Trichocoma), two in the Thermoascaceae (Paecilomyces, Thermoascus) and one in the Penicillaginaceae (Penicillago). The classification of the Elaphomycetaceae was not part of this study, but according to literature two genera are present in this family (Elaphomyces and Pseudotulostoma). The use of an infrageneric classification system has a long tradition in Aspergillus and Penicillium. Most recent taxonomic studies focused on the sectional level, resulting in a well-established sectional classification in these genera. In contrast, a series classification in Aspergillus and Penicillium is often outdated or lacking, but is still relevant, e.g., the allocation of a species to a series can be highly predictive in what functional characters the species might have and might be useful when using a phenotype-based identification. The majority of the series in Aspergillus and Penicillium are invalidly described and here we introduce a new series classification. Using a phylogenetic approach, often supported by phenotypic, physiologic and/or extrolite data, Aspergillus is subdivided in six subgenera, 27 sections (five new) and 75 series (73 new, one new combination), and Penicillium in two subgenera, 32 sections (seven new) and 89 series (57 new, six new combinations). Correct identification of species belonging to the Eurotiales is difficult, but crucial, as the species name is the linking pin to information. Lists of accepted species are a helpful aid for researchers to obtain a correct identification using the current taxonomic schemes. In the most recent list from 2014, 339 Aspergillus, 354 Penicillium and 88 Talaromyces species were accepted. These numbers increased significantly, and the current list includes 446 Aspergillus (32 % increase), 483 Penicillium (36 % increase) and 171 Talaromyces (94 % increase) species, showing the large diversity and high interest in these genera. We expanded this list with all genera and species belonging to the Eurotiales (except those belonging to Elaphomycetaceae). The list includes 1 187 species, distributed over 27 genera, and contains MycoBank numbers, collection numbers of type and ex-type cultures, subgenus, section and series classification data, information on the mode of reproduction, and GenBank accession numbers of ITS, beta-tubulin (BenA), calmodulin (CaM) and RNA polymerase II second largest subunit (RPB2) gene sequences.
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Key Words
- Acidotalaromyces Houbraken, Frisvad & Samson
- Acidotalaromyces lignorum (Stolk) Houbraken, Frisvad & Samson
- Ascospirella Houbraken, Frisvad & Samson
- Ascospirella lutea (Zukal) Houbraken, Frisvad & Samson
- Aspergillus chaetosartoryae Hubka, Kocsubé & Houbraken
- Classification
- Evansstolkia Houbraken, Frisvad & Samson
- Evansstolkia leycettana (H.C. Evans & Stolk) Houbraken, Frisvad & Samson
- Hamigera brevicompacta (H.Z. Kong) Houbraken, Frisvad & Samson
- Infrageneric classification
- New combinations, series
- New combinations, species
- New genera
- New names
- New sections
- New series
- New taxa
- Nomenclature
- Paecilomyces lagunculariae (C. Ram) Houbraken, Frisvad & Samson
- Penicillaginaceae Houbraken, Frisvad & Samson
- Penicillago kabunica (Baghd.) Houbraken, Frisvad & Samson
- Penicillago mirabilis (Beliakova & Milko) Houbraken, Frisvad & Samson
- Penicillago moldavica (Milko & Beliakova) Houbraken, Frisvad & Samson
- Phialomyces arenicola (Chalab.) Houbraken, Frisvad & Samson
- Phialomyces humicoloides (Bills & Heredia) Houbraken, Frisvad & Samson
- Phylogeny
- Polythetic classes
- Pseudohamigera Houbraken, Frisvad & Samson
- Pseudohamigera striata (Raper & Fennell) Houbraken, Frisvad & Samson
- Talaromyces resinae (Z.T. Qi & H.Z. Kong) Houbraken & X.C. Wang
- Talaromyces striatoconidius Houbraken, Frisvad & Samson
- Taxonomic novelties: New family
- Thermoascus verrucosus (Samson & Tansey) Houbraken, Frisvad & Samson
- Thermoascus yaguchii Houbraken, Frisvad & Samson
- in Aspergillus: sect. Bispori S.W. Peterson, Varga, Frisvad, Samson ex Houbraken
- in Aspergillus: ser. Acidohumorum Houbraken & Frisvad
- in Aspergillus: ser. Inflati (Stolk & Samson) Houbraken & Frisvad
- in Penicillium: sect. Alfrediorum Houbraken & Frisvad
- in Penicillium: ser. Adametziorum Houbraken & Frisvad
- in Penicillium: ser. Alutacea (Pitt) Houbraken & Frisvad
- sect. Crypta Houbraken & Frisvad
- sect. Eremophila Houbraken & Frisvad
- sect. Formosana Houbraken & Frisvad
- sect. Griseola Houbraken & Frisvad
- sect. Inusitata Houbraken & Frisvad
- sect. Lasseniorum Houbraken & Frisvad
- sect. Polypaecilum Houbraken & Frisvad
- sect. Raperorum S.W. Peterson, Varga, Frisvad, Samson ex Houbraken
- sect. Silvatici S.W. Peterson, Varga, Frisvad, Samson ex Houbraken
- sect. Vargarum Houbraken & Frisvad
- ser. Alliacei Houbraken & Frisvad
- ser. Ambigui Houbraken & Frisvad
- ser. Angustiporcata Houbraken & Frisvad
- ser. Arxiorum Houbraken & Frisvad
- ser. Atramentosa Houbraken & Frisvad
- ser. Aurantiobrunnei Houbraken & Frisvad
- ser. Avenacei Houbraken & Frisvad
- ser. Bertholletiarum Houbraken & Frisvad
- ser. Biplani Houbraken & Frisvad
- ser. Brevicompacta Houbraken & Frisvad
- ser. Brevipedes Houbraken & Frisvad
- ser. Brunneouniseriati Houbraken & Frisvad
- ser. Buchwaldiorum Houbraken & Frisvad
- ser. Calidousti Houbraken & Frisvad
- ser. Canini Houbraken & Frisvad
- ser. Carbonarii Houbraken & Frisvad
- ser. Cavernicolarum Houbraken & Frisvad
- ser. Cervini Houbraken & Frisvad
- ser. Chevalierorum Houbraken & Frisvad
- ser. Cinnamopurpurea Houbraken & Frisvad
- ser. Circumdati Houbraken & Frisvad
- ser. Clavigera Houbraken & Frisvad
- ser. Conjuncti Houbraken & Frisvad
- ser. Copticolarum Houbraken & Frisvad
- ser. Coremiiformes Houbraken & Frisvad
- ser. Corylophila Houbraken & Frisvad
- ser. Costaricensia Houbraken & Frisvad
- ser. Cremei Houbraken & Frisvad
- ser. Crustacea (Pitt) Houbraken & Frisvad
- ser. Dalearum Houbraken & Frisvad
- ser. Deflecti Houbraken & Frisvad
- ser. Egyptiaci Houbraken & Frisvad
- ser. Erubescentia (Pitt) Houbraken & Frisvad
- ser. Estinogena Houbraken & Frisvad
- ser. Euglauca Houbraken & Frisvad
- ser. Fennelliarum Houbraken & Frisvad
- ser. Flavi Houbraken & Frisvad
- ser. Flavipedes Houbraken & Frisvad
- ser. Fortuita Houbraken & Frisvad
- ser. Fumigati Houbraken & Frisvad
- ser. Funiculosi Houbraken & Frisvad
- ser. Gallaica Houbraken & Frisvad
- ser. Georgiensia Houbraken & Frisvad
- ser. Goetziorum Houbraken & Frisvad
- ser. Gracilenta Houbraken & Frisvad
- ser. Halophilici Houbraken & Frisvad
- ser. Herqueorum Houbraken & Frisvad
- ser. Heteromorphi Houbraken & Frisvad
- ser. Hoeksiorum Houbraken & Frisvad
- ser. Homomorphi Houbraken & Frisvad
- ser. Idahoensia Houbraken & Frisvad
- ser. Implicati Houbraken & Frisvad
- ser. Improvisa Houbraken & Frisvad
- ser. Indica Houbraken & Frisvad
- ser. Japonici Houbraken & Frisvad
- ser. Jiangxiensia Houbraken & Frisvad
- ser. Kalimarum Houbraken & Frisvad
- ser. Kiamaensia Houbraken & Frisvad
- ser. Kitamyces Houbraken & Frisvad
- ser. Lapidosa (Pitt) Houbraken & Frisvad
- ser. Leporum Houbraken & Frisvad
- ser. Leucocarpi Houbraken & Frisvad
- ser. Livida Houbraken & Frisvad
- ser. Longicatenata Houbraken & Frisvad
- ser. Macrosclerotiorum Houbraken & Frisvad
- ser. Monodiorum Houbraken & Frisvad
- ser. Multicolores Houbraken & Frisvad
- ser. Neoglabri Houbraken & Frisvad
- ser. Neonivei Houbraken & Frisvad
- ser. Nidulantes Houbraken & Frisvad
- ser. Nigri Houbraken & Frisvad
- ser. Nivei Houbraken & Frisvad
- ser. Nodula Houbraken & Frisvad
- ser. Nomiarum Houbraken & Frisvad
- ser. Noonimiarum Houbraken & Frisvad
- ser. Ochraceorosei Houbraken & Frisvad
- ser. Olivimuriarum Houbraken & Frisvad
- ser. Osmophila Houbraken & Frisvad
- ser. Paradoxa Houbraken & Frisvad
- ser. Paxillorum Houbraken & Frisvad
- ser. Penicillioides Houbraken & Frisvad
- ser. Phoenicea Houbraken & Frisvad
- ser. Pinetorum (Pitt) Houbraken & Frisvad
- ser. Polypaecilum Houbraken & Frisvad
- ser. Pulvini Houbraken & Frisvad
- ser. Quercetorum Houbraken & Frisvad
- ser. Raistrickiorum Houbraken & Frisvad
- ser. Ramigena Houbraken & Frisvad
- ser. Restricti Houbraken & Frisvad
- ser. Robsamsonia Houbraken & Frisvad
- ser. Rolfsiorum Houbraken & Frisvad
- ser. Roseopurpurea Houbraken & Frisvad
- ser. Rubri Houbraken & Frisvad
- ser. Salinarum Houbraken & Frisvad
- ser. Samsoniorum Houbraken & Frisvad
- ser. Saturniformia Houbraken & Frisvad
- ser. Scabrosa Houbraken & Frisvad
- ser. Sclerotigena Houbraken & Frisvad
- ser. Sclerotiorum Houbraken & Frisvad
- ser. Sheariorum Houbraken & Frisvad
- ser. Simplicissima Houbraken & Frisvad
- ser. Soppiorum Houbraken & Frisvad
- ser. Sparsi Houbraken & Frisvad
- ser. Spathulati Houbraken & Frisvad
- ser. Spelaei Houbraken & Frisvad
- ser. Speluncei Houbraken & Frisvad
- ser. Spinulosa Houbraken & Frisvad
- ser. Stellati Houbraken & Frisvad
- ser. Steyniorum Houbraken & Frisvad
- ser. Sublectatica Houbraken & Frisvad
- ser. Sumatraensia Houbraken & Frisvad
- ser. Tamarindosolorum Houbraken & Frisvad
- ser. Teporium Houbraken & Frisvad
- ser. Terrei Houbraken & Frisvad
- ser. Thermomutati Houbraken & Frisvad
- ser. Thiersiorum Houbraken & Frisvad
- ser. Thomiorum Houbraken & Frisvad
- ser. Unguium Houbraken & Frisvad
- ser. Unilaterales Houbraken & Frisvad
- ser. Usti Houbraken & Frisvad
- ser. Verhageniorum Houbraken & Frisvad
- ser. Versicolores Houbraken & Frisvad
- ser. Virgata Houbraken & Frisvad
- ser. Viridinutantes Houbraken & Frisvad
- ser. Vitricolarum Houbraken & Frisvad
- ser. Wentiorum Houbraken & Frisvad
- ser. Westlingiorum Houbraken & Frisvad
- ser. Whitfieldiorum Houbraken & Frisvad
- ser. Xerophili Houbraken & Frisvad
- series Tularensia (Pitt) Houbraken & Frisvad
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Affiliation(s)
- J. Houbraken
- Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands
| | - S. Kocsubé
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Szeged, Hungary
| | - C.M. Visagie
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, P. Bag X20, Hatfield, Pretoria, 0028, South Africa
| | - N. Yilmaz
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, P. Bag X20, Hatfield, Pretoria, 0028, South Africa
| | - X.-C. Wang
- Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, No. 3, 1st Beichen West Road, Chaoyang District, Beijing, 100101, China
| | - M. Meijer
- Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands
| | - B. Kraak
- Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands
| | - V. Hubka
- Department of Botany, Charles University in Prague, Prague, Czech Republic
| | - K. Bensch
- Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands
| | - R.A. Samson
- Westerdijk Fungal Biodiversity Institute, Utrecht, The Netherlands
| | - J.C. Frisvad
- Department of Biotechnology and Biomedicine Technical University of Denmark, Søltofts Plads, B. 221, Kongens Lyngby, DK 2800, Denmark
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7
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Sensing and transduction of nutritional and chemical signals in filamentous fungi: Impact on cell development and secondary metabolites biosynthesis. Biotechnol Adv 2019; 37:107392. [PMID: 31034961 DOI: 10.1016/j.biotechadv.2019.04.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 04/22/2019] [Accepted: 04/25/2019] [Indexed: 11/23/2022]
Abstract
Filamentous fungi respond to hundreds of nutritional, chemical and environmental signals that affect expression of primary metabolism and biosynthesis of secondary metabolites. These signals are sensed at the membrane level by G protein coupled receptors (GPCRs). GPCRs contain usually seven transmembrane domains, an external amino terminal fragment that interacts with the ligand, and an internal carboxy terminal end interacting with the intracellular G protein. There is a great variety of GPCRs in filamentous fungi involved in sensing of sugars, amino acids, cellulose, cell-wall components, sex pheromones, oxylipins, calcium ions and other ligands. Mechanisms of signal transduction at the membrane level by GPCRs are discussed, including the internalization and compartmentalisation of these sensor proteins. We have identified and analysed the GPCRs in the genome of Penicillium chrysogenum and compared them with GPCRs of several other filamentous fungi. We have found 66 GPCRs classified into 14 classes, depending on the ligand recognized by these proteins, including most previously proposed classes of GPCRs. We have found 66 putative GPCRs, representatives of twelve of the fourteen previously proposed classes of GPCRs, depending on the ligand recognized by these proteins. A staggering fortytwo putative members of the new GPCR class XIV, the so-called Pth11 sensors of cellulosic material as reported for Neurospora crassa and some other fungi, were identified. Several GPCRs sensing sex pheromones, known in yeast and in several fungi, were also identified in P. chrysogenum, confirming the recent unravelling of the hidden sexual capacity of this species. Other sensing mechanisms do not involve GPCRs, including the two-component systems (HKRR), the HOG signalling system and the PalH mediated pH transduction sensor. GPCR sensor proteins transmit their signals by interacting with intracellular heterotrimeric G proteins, that are well known in several fungi, including P. chrysogenum. These G proteins are inactive in the GDP containing heterotrimeric state, and become active by nucleotide exchange, allowing the separation of the heterotrimeric protein in active Gα and Gβγ dimer subunits. The conversion of GTP in GDP is mediated by the endogenous GTPase activity of the G proteins. Downstream of the ligand interaction, the activated Gα protein and also the Gβ/Gγ dimer, transduce the signals through at least three different cascades: adenylate cyclase/cAMP, MAPK kinase, and phospholipase C mediated pathways.
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8
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Novel Partitivirus Enhances Virulence of and Causes Aberrant Gene Expression in Talaromyces marneffei. mBio 2018; 9:mBio.00947-18. [PMID: 29895639 PMCID: PMC6016240 DOI: 10.1128/mbio.00947-18] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Talaromyces marneffei is the most important thermal dimorphic fungus causing systemic mycosis in Southeast Asia. We report the discovery of a novel partitivirus, Talaromyces marneffeipartitivirus-1 (TmPV1). TmPV1 was detected in 7 (12.7%) of 55 clinical T. marneffei isolates. Complete genome sequencing of the seven TmPV1 isolates revealed two double-stranded RNA (dsRNA) segments encoding RNA-dependent RNA polymerase (RdRp) and capsid protein, respectively. Phylogenetic analysis showed that TmPV1 occupied a distinct clade among the members of the genus Gammapartitivirus Transmission electron microscopy confirmed the presence of isometric, nonenveloped viral particles of 30 to 45 nm in diameter, compatible with partitiviruses, in TmPV1-infected T. marneffei Quantitative reverse transcription-PCR (qRT-PCR) demonstrated higher viral load of TmPV1 in the yeast phase than in the mycelial phase of T. marneffei Two virus-free isolates, PM1 and PM41, were successfully infected by purified TmPV1 using protoplast transfection. Mice challenged with TmPV1-infected T. marneffei isolates showed significantly shortened survival time (P < 0.0001) and higher fungal burden in organs than mice challenged with isogenic TmPV1-free isolates. Transcriptomic analysis showed that TmPV1 causes aberrant expression of various genes in T. marneffei, with upregulation of potential virulence factors and suppression of RNA interference (RNAi)-related genes. This is the first report of a mycovirus in a thermally dimorphic fungus. Further studies are required to ascertain the mechanism whereby TmPV1 enhances the virulence of T. marneffei in mice and the potential role of RNAi-related genes in antiviral defense in T. marneffeiIMPORTANCETalaromyces marneffei (formerly Penicillium marneffei) is the most important thermal dimorphic fungus in Southeast Asia, causing highly fatal systemic penicilliosis in HIV-infected and immunocompromised patients. We discovered a novel mycovirus, TmPV1, in seven clinical isolates of T. marneffei TmPV1 belongs to the genus Gammapartitivirus of the family Partitiviridae We showed that TmPV1 enhanced the virulence of T. marneffei in mice, with shortened survival time and higher fungal burden in the organs of mice challenged with TmPV1-infected T. marneffei isolates than in those of mice challenged with virus-free isogenic isolates. Transcriptomics analysis showed that TmPV1 altered the expression of genes involved in various cellular processes in T. marneffei, with upregulation of potential virulence factors and suppression of RNAi machinery which may be involved in antiviral defense. This is the first report of a mycovirus in a thermal dimorphic fungus. The present results offer insights into mycovirus-fungus interactions and pathogenesis of thermal dimorphic fungi.
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9
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Ellett F, Pazhakh V, Pase L, Benard EL, Weerasinghe H, Azabdaftari D, Alasmari S, Andrianopoulos A, Lieschke GJ. Macrophages protect Talaromyces marneffei conidia from myeloperoxidase-dependent neutrophil fungicidal activity during infection establishment in vivo. PLoS Pathog 2018; 14:e1007063. [PMID: 29883484 PMCID: PMC6010348 DOI: 10.1371/journal.ppat.1007063] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 06/20/2018] [Accepted: 04/30/2018] [Indexed: 12/21/2022] Open
Abstract
Neutrophils and macrophages provide the first line of cellular defence against pathogens once physical barriers are breached, but can play very different roles for each specific pathogen. This is particularly so for fungal pathogens, which can occupy several niches in the host. We developed an infection model of talaromycosis in zebrafish embryos with the thermally-dimorphic intracellular fungal pathogen Talaromyces marneffei and used it to define different roles of neutrophils and macrophages in infection establishment. This system models opportunistic human infection prevalent in HIV-infected patients, as zebrafish embryos have intact innate immunity but, like HIV-infected talaromycosis patients, lack a functional adaptive immune system. Importantly, this new talaromycosis model permits thermal shifts not possible in mammalian models, which we show does not significantly impact on leukocyte migration, phagocytosis and function in an established Aspergillus fumigatus model. Furthermore, the optical transparency of zebrafish embryos facilitates imaging of leukocyte/pathogen interactions in vivo. Following parenteral inoculation, T. marneffei conidia were phagocytosed by both neutrophils and macrophages. Within these different leukocytes, intracellular fungal form varied, indicating that triggers in the intracellular milieu can override thermal morphological determinants. As in human talaromycosis, conidia were predominantly phagocytosed by macrophages rather than neutrophils. Macrophages provided an intracellular niche that supported yeast morphology. Despite their minor role in T. marneffei conidial phagocytosis, neutrophil numbers increased during infection from a protective CSF3-dependent granulopoietic response. By perturbing the relative abundance of neutrophils and macrophages during conidial inoculation, we demonstrate that the macrophage intracellular niche favours infection establishment by protecting conidia from a myeloperoxidase-dependent neutrophil fungicidal activity. These studies provide a new in vivo model of talaromycosis with several advantages over previous models. Our findings demonstrate that limiting T. marneffei's opportunity for macrophage parasitism and thereby enhancing this pathogen's exposure to effective neutrophil fungicidal mechanisms may represent a novel host-directed therapeutic opportunity.
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Affiliation(s)
- Felix Ellett
- Australian Regenerative Medicine Institute, Monash University, Clayton, Victoria, Australia
- Cancer and Haematology Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Victoria, Australia
| | - Vahid Pazhakh
- Australian Regenerative Medicine Institute, Monash University, Clayton, Victoria, Australia
| | - Luke Pase
- Australian Regenerative Medicine Institute, Monash University, Clayton, Victoria, Australia
- Cancer and Haematology Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
| | - Erica L. Benard
- Cancer and Haematology Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
| | - Harshini Weerasinghe
- Genetics, Genomics and Systems Biology, School of BioSciences, University of Melbourne, Victoria, Australia
| | - Denis Azabdaftari
- Australian Regenerative Medicine Institute, Monash University, Clayton, Victoria, Australia
| | - Sultan Alasmari
- Australian Regenerative Medicine Institute, Monash University, Clayton, Victoria, Australia
| | - Alex Andrianopoulos
- Genetics, Genomics and Systems Biology, School of BioSciences, University of Melbourne, Victoria, Australia
| | - Graham J. Lieschke
- Australian Regenerative Medicine Institute, Monash University, Clayton, Victoria, Australia
- Cancer and Haematology Division, Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, Australia
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10
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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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11
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Yu Y, Amich J, Will C, Eagle CE, Dyer PS, Krappmann S. The novel Aspergillus fumigatus MAT1-2-4 mating-type gene is required for mating and cleistothecia formation. Fungal Genet Biol 2017; 108:1-12. [PMID: 28889020 DOI: 10.1016/j.fgb.2017.09.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 08/28/2017] [Accepted: 09/01/2017] [Indexed: 10/18/2022]
Abstract
Sexual propagation accompanied by recombination and the formation of spore-containing fruiting bodies is a cornerstone of fungal genetics and biology. In the human pathogen Aspergillus fumigatus sexual identity has previously been shown to be determined by MAT1-1-1 or MAT1-2-1 genes which act as transcriptional regulators and are present within idiomorphs found at the MAT locus. We here report the identification and first characterization of a further novel gene, termed MAT1-2-4, that is present in the MAT1-2 idiomorph of A. fumigatus. A mating-type swapping strategy was used to achieve an unbiased deletion of the MAT1-2-4 gene with no impact on MAT1-2-1 gene expression. Phenotypical characterization of the resulting strain revealed an inability to mate with the compatible MAT1-1 progenitor, demonstrating that the MAT1-2-4 gene product is a genuine mating-type factor required for correct sexual development. A GPI-anchored protein of unknown function was identified as interaction partner. However, no functional role in the mating process or ascosporogenesis could be demonstrated by deletion analysis for this latter protein, although a role in heterokaryon formation is suggested. Bioinformatic analysis also demonstrated the presence of MAT1-2-4 homologues in some, but not all, other Aspergillus species and the evolutionary origins and implications of the MAT1-2-4 gene are discussed.
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Affiliation(s)
- Yidong Yu
- Mikrobiologisches Institut - Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen and Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany
| | - Jorge Amich
- Research Center for Infectious Diseases, Julius-Maximilians-Universität Würzburg, Germany
| | - Cornelia Will
- Mikrobiologisches Institut - Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen and Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany
| | - Carly E Eagle
- School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Paul S Dyer
- School of Life Sciences, University of Nottingham, Nottingham NG7 2RD, United Kingdom
| | - Sven Krappmann
- Mikrobiologisches Institut - Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen and Friedrich-Alexander-Universität Erlangen-Nürnberg, Germany.
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12
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Wilken PM, Steenkamp ET, Wingfield MJ, de Beer ZW, Wingfield BD. Which MAT gene? Pezizomycotina (Ascomycota) mating-type gene nomenclature reconsidered. FUNGAL BIOL REV 2017. [DOI: 10.1016/j.fbr.2017.05.003] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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13
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Mating-type genes of the anamorphic fungus Ulocladium botrytis affect both asexual sporulation and sexual reproduction. Sci Rep 2017; 7:7932. [PMID: 28801599 PMCID: PMC5554195 DOI: 10.1038/s41598-017-08471-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2016] [Accepted: 07/13/2017] [Indexed: 11/23/2022] Open
Abstract
Ulocladium was thought to be a strictly asexual genus of filamentous fungi. However, Ulocladium strains were shown to possess both MAT1-1-1 and MAT1-2-1 genes as observed in homothallic filamentous Ascomycetes. Here, we demonstrate that the U. botrytis MAT genes play essential roles for controlling asexual traits (conidial size and number). Using reciprocal genetic transformation, we demonstrate that MAT genes from the related heterothallic species Cochliobolus heterostrophus can also influence U. botrytis colony growth, conidial number and size, and have a strong effect on the range of the number of septa/conidium. Moreover, U. botrytis MAT genes can also affect similar aspects of asexual reproduction when expressed in C. heterostrophus. Heterologous complementation using C. heterostrophus MAT genes shows that they have lost the ability to regulate sexual reproduction in U. botrytis, under the conditions we employed, while the reciprocal heterologous complementation demonstrates that U. botrytis MAT genes have the ability to partially induce sexual reproduction in C. heterostrophus. Thus, the genetic backgrounds of C. heterostrophus and U. botrytis play significant roles in determining the function of MAT genes on sexual reproduction in these two fungi species. These data further support the role of MAT genes in controlling asexual growth in filamentous Ascomycetes but also confirm that heterothallic and homothallic Dothideomycete fungi can be interconverted by the exchange of MAT genes.
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14
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Lau SKP, Tsang CC, Woo PCY. Talaromyces marneffei Genomic, Transcriptomic, Proteomic and Metabolomic Studies Reveal Mechanisms for Environmental Adaptations and Virulence. Toxins (Basel) 2017; 9:E192. [PMID: 28608842 PMCID: PMC5488042 DOI: 10.3390/toxins9060192] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2017] [Revised: 06/09/2017] [Accepted: 06/10/2017] [Indexed: 11/22/2022] Open
Abstract
Talaromycesmarneffei is a thermally dimorphic fungus causing systemic infections in patients positive for HIV or other immunocompromised statuses. Analysis of its ~28.9 Mb draft genome and additional transcriptomic, proteomic and metabolomic studies revealed mechanisms for environmental adaptations and virulence. Meiotic genes and genes for pheromone receptors, enzymes which process pheromones, and proteins involved in pheromone response pathway are present, indicating its possibility as a heterothallic fungus. Among the 14 Mp1p homologs, only Mp1p is a virulence factor binding a variety of host proteins, fatty acids and lipids. There are 23 polyketide synthase genes, one for melanin and two for mitorubrinic acid/mitorubrinol biosynthesis, which are virulence factors. Another polyketide synthase is for biogenesis of the diffusible red pigment, which consists of amino acid conjugates of monascorubin and rubropunctatin. Novel microRNA-like RNAs (milRNAs) and processing proteins are present. The dicer protein, dcl-2, is required for biogenesis of two milRNAs, PM-milR-M1 and PM-milR-M2, which are more highly expressed in hyphal cells. Comparative transcriptomics showed that tandem repeat-containing genes were overexpressed in yeast phase, generating protein polymorphism among cells, evading host's immunity. Comparative proteomics between yeast and hyphal cells revealed that glyceraldehyde-3-phosphate dehydrogenase, up-regulated in hyphal cells, is an adhesion factor for conidial attachment.
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Affiliation(s)
- Susanna K P Lau
- Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong.
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Pokfulam, Hong Kong.
- Research Centre of Infection and Immunology, The University of Hong Kong, Pokfulam, Hong Kong.
- Carol Yu Centre for Infection, The University of Hong Kong, Pokfulam, Hong Kong.
- Collaborative Innovation Centre for Diagnosis and Treatment of Infectious Diseases, The University of Hong Kong, Pokfulam, Hong Kong.
| | - Chi-Ching Tsang
- Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong.
| | - Patrick C Y Woo
- Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong.
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Pokfulam, Hong Kong.
- Research Centre of Infection and Immunology, The University of Hong Kong, Pokfulam, Hong Kong.
- Carol Yu Centre for Infection, The University of Hong Kong, Pokfulam, Hong Kong.
- Collaborative Innovation Centre for Diagnosis and Treatment of Infectious Diseases, The University of Hong Kong, Pokfulam, Hong Kong.
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15
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Tam EWT, Tsang CC, Lau SKP, Woo PCY. Comparative mitogenomic and phylogenetic characterization on the complete mitogenomes of Talaromyces ( Penicillium) marneffei. MITOCHONDRIAL DNA PART B-RESOURCES 2017; 1:941-942. [PMID: 33473685 PMCID: PMC7800151 DOI: 10.1080/23802359.2016.1261610] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We report the complete mitochondrial DNA (mtDNA) sequences of four Talaromyces marneffei strains and performed comparative genomic and phylogenetic analyses. The gene orders of the four mtDNAs are identical to the previously published mtDNA of strain PM1 (nad4l, nad5, nad2, atp9, cob, nad1, nad4, atp8, atp6, nad6, cox3, rps, cox1, nad3, cox2). Phylogenetic analysis showed that the four mtDNAs were clustered with that of PM1 with high bootstrap support. Compared to mtDNA of PM1, the only non-synonymous mutation was located in nad2 (T505M) of strain PM26. Synonymous single nucleotide polymorphisms were observed at eight positions in the four mtDNAs.
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Affiliation(s)
- Emily W T Tam
- Department of Microbiology, The University of Hong Kong, Hong Kong
| | - Chi-Ching Tsang
- Department of Microbiology, The University of Hong Kong, Hong Kong
| | - Susanna K P Lau
- Department of Microbiology, The University of Hong Kong, Hong Kong.,State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong.,Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong.,Carol Yu Centre of Infection, The University of Hong Kong, Hong Kong.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The University of Hong Kong, Hong Kong
| | - Patrick C Y Woo
- Department of Microbiology, The University of Hong Kong, Hong Kong.,State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong.,Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong.,Carol Yu Centre of Infection, The University of Hong Kong, Hong Kong.,Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The University of Hong Kong, Hong Kong
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16
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Woo PCY, Lau SKP, Lau CCY, Tung ETK, Chong KTK, Yang F, Zhang H, Lo RKC, Cai JP, Au-Yeung RKH, Ng WF, Tse H, Wong SSY, Xu S, Lam WH, Tse MK, Sze KH, Kao RY, Reiner NE, Hao Q, Yuen KY. Mp1p Is a Virulence Factor in Talaromyces (Penicillium) marneffei. PLoS Negl Trop Dis 2016; 10:e0004907. [PMID: 27560160 PMCID: PMC4999278 DOI: 10.1371/journal.pntd.0004907] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 07/14/2016] [Indexed: 12/03/2022] Open
Abstract
Background Talaromyces marneffei is an opportunistic dimorphic fungus prevalent in Southeast Asia. We previously demonstrated that Mp1p is an immunogenic surface and secretory mannoprotein of T. marneffei. Since Mp1p is a surface protein that can generate protective immunity, we hypothesized that Mp1p and/or its homologs are virulence factors. Methodology/Principal Findings We examined the pathogenic roles of Mp1p and its homologs in a mouse model. All mice died 21 and 30 days after challenge with wild-type T. marneffei PM1 and MP1 complemented mutant respectively. None of the mice died 60 days after challenge with MP1 knockout mutant (P<0.0001). Seventy percent of mice died 60 days after challenge with MP1 knockdown mutant (P<0.0001). All mice died after challenge with MPLP1 to MPLP13 knockdown mutants, suggesting that only Mp1p plays a significant role in virulence. The mean fungal loads of PM1 and MP1 complemented mutant in the liver, lung, kidney and spleen were significantly higher than those of the MP1 knockout mutant. Similarly, the mean load of PM1 in the liver, lung and spleen were significantly higher than that of the MP1 knockdown mutant. Histopathological studies showed an abundance of yeast in the kidney, spleen, liver and lung with more marked hepatic and splenic necrosis in mice challenged with PM1 compared to MP1 knockout and MP1 knockdown mutants. Likewise, a higher abundance of yeast was observed in the liver and spleen of mice challenged with MP1 complemented mutant compared to MP1 knockout mutant. PM1 and MP1 complemented mutant survived significantly better than MP1 knockout mutant in macrophages at 48 hours (P<0.01) post-infection. The mean fungal counts of Pichia pastoris GS115-MP1 in the liver (P<0.001) and spleen (P<0.05) of mice were significantly higher than those of GS115 at 24 hours post-challenge. Conclusions/Significance Mp1p is a key virulence factor of T. marneffei. Mp1p mediates virulence by improving the survival of T. marneffei in macrophages. Talaromyces (Penicillium) marneffei is an opportunistic thermal dimorphic fungus most prevalent in Southeast Asia. Our team has previously shown that Mp1p, a protein encoded by the MP1 gene, is an immunogenic surface and secretory protein of T. marneffei. In this study, we showed that mice challenged with T. marneffei with the MP1 gene died but those challenged with T. marneffei without the MP1 gene did not die. There was also significantly higher fungal load and more necrosis in organs of mice challenged with T. marneffei with the MP1 gene than T. marneffei without the MP1 gene. Furthermore, T. marneffei with the MP1 gene survived better in macrophages than T. marneffei without the MP1 gene and Pichia pastoris with the MP1 gene survived in mice better than P. pastoris without the MP1 gene. Our data support that Mp1p is a key virulence factor of T. marneffei and Mp1p mediates virulence by improving the survival of T. marneffei in macrophages.
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Affiliation(s)
- Patrick C. Y. Woo
- Department of Microbiology, The University of Hong Kong, Hong Kong
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong
- Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong
- Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong
| | - Susanna K. P. Lau
- Department of Microbiology, The University of Hong Kong, Hong Kong
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong
- Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong
- Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong
| | - Candy C. Y. Lau
- Department of Microbiology, The University of Hong Kong, Hong Kong
| | | | - Ken T. K. Chong
- Department of Microbiology, The University of Hong Kong, Hong Kong
| | - Fengjuan Yang
- Department of Microbiology, The University of Hong Kong, Hong Kong
| | - Hongmin Zhang
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong
| | - Raymond K. C. Lo
- Department of Microbiology, The University of Hong Kong, Hong Kong
| | - Jian-Pao Cai
- Department of Microbiology, The University of Hong Kong, Hong Kong
| | | | - Wing-Fung Ng
- Department of Pathology, United Christian Hospital and Tseung Kwan O Hospital, Hong Kong
| | - Herman Tse
- Department of Microbiology, The University of Hong Kong, Hong Kong
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong
- Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong
- Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong
| | - Samson S. Y. Wong
- Department of Microbiology, The University of Hong Kong, Hong Kong
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong
- Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong
- Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong
| | - Simin Xu
- Department of Microbiology, The University of Hong Kong, Hong Kong
| | - Wai Hei Lam
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong
| | - Man-Kit Tse
- Department of Microbiology, The University of Hong Kong, Hong Kong
| | - Kong Hung Sze
- Department of Microbiology, The University of Hong Kong, Hong Kong
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong
- Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong
- Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong
| | - Richard Y. Kao
- Department of Microbiology, The University of Hong Kong, Hong Kong
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong
- Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong
- Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong
| | - Neil E. Reiner
- Department of Medicine, University of British Columbia, Vancouver, Canada
| | - Quan Hao
- School of Biomedical Sciences, The University of Hong Kong, Hong Kong
| | - Kwok-Yung Yuen
- Department of Microbiology, The University of Hong Kong, Hong Kong
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong
- Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong
- Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong
- * E-mail:
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17
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Chan JFW, Lau SKP, Yuen KY, Woo PCY. Talaromyces (Penicillium) marneffei infection in non-HIV-infected patients. Emerg Microbes Infect 2016; 5:e19. [PMID: 26956447 PMCID: PMC4820671 DOI: 10.1038/emi.2016.18] [Citation(s) in RCA: 161] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2015] [Revised: 12/04/2015] [Accepted: 12/08/2015] [Indexed: 12/18/2022]
Abstract
Talaromyces (Penicillium) marneffei is an important pathogenic thermally dimorphic fungus causing systemic mycosis in Southeast Asia. The clinical significance of T. marneffei became evident when the human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome epidemic arrived in Southeast Asia in 1988. Subsequently, a decline in the incidence of T. marneffei infection among HIV-infected patients was seen in regions with access to highly active antiretroviral therapy and other control measures for HIV. Since the 1990s, an increasing number of T. marneffei infections have been reported among non-HIV-infected patients with impaired cell-mediated immunity. Their comorbidities included primary adult-onset immunodeficiency due to anti-interferon-gamma autoantibodies and secondary immunosuppressive conditions including other autoimmune diseases, solid organ and hematopoietic stem cell transplantations, T-lymphocyte-depleting immunsuppressive drugs and novel anti-cancer targeted therapies such as anti-CD20 monoclonal antibodies and kinase inhibitors. Moreover, improved immunological diagnostics identified more primary immunodeficiency syndromes associated with T. marneffei infection in children. The higher case-fatality rate of T. marneffei infection in non-HIV-infected than HIV-infected patients might be related to delayed diagnosis due to the lack of clinical suspicion. Correction of the underlying immune defects and early use of antifungals are important treatment strategies. Clinicians should be familiar with the changing epidemiology and clinical management of T. marneffei infection among non-HIV-infected patients.
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Affiliation(s)
- Jasper FW Chan
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
- Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong, China
- Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China
| | - Susanna KP Lau
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
- Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong, China
- Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China
| | - Kwok-Yung Yuen
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
- Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong, China
- Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China
| | - Patrick CY Woo
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
- Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong, China
- Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China
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Yilmaz N, Hagen F, Meis JF, Houbraken J, Samson RA. Discovery of a sexual cycle in Talaromyces amestolkiae. Mycologia 2015; 108:70-9. [PMID: 26577610 DOI: 10.3852/15-014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 10/18/2015] [Indexed: 11/10/2022]
Abstract
Talaromyces amestolkiae is a common cosmopolitan species that has been cultured from indoor house dust, sputum and lungs from cystic fibrosis patients, indoor air, wheat, soil, pineapple, sculptures and manure. It was described as an asexual Talaromyces species and was reported to produce black sclerotia. In this study we report on the induction of sexual reproductive structures in T. amestolkiae. The mating type of 18 T. amestolkiae strains was determined with MAT-specific primers. Subsequently opposite mating types were inoculated on oatmeal agar and malt-extract agar and incubated 6-20 wk at 25 and 30 C in darkness. After incubation single ascospore isolations were made and evidence of recombination in the offspring was examined by amplified fragment length polymorphism and pairwise homoplasy index test, which is implemented in Splitstree4. The offspring displayed clear evidence of recombination on a genetic level as shown in the variations observed between banding patterns in the amplified fragment length polymorphism. Also a net-like and reticulated NeighborNet was observed and the pairwise homoplasy index test for recombination supported the presence of recombination (P = 0.003372). The distribution of MAT1-1 and MAT1-2 genes in the progeny showed a close to 1:1 ratio. Talaromyces amestolkiae is only the second heterothallic Talaromyces species to produce ascomata and ascospores under laboratory conditions.
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Affiliation(s)
- Neriman Yilmaz
- CBS-KNAW Fungal Biodiversity Centre, Uppsalalaan 8, 3584 CT Utrecht, the Netherlands; Microbiology, Department of Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
| | - Ferry Hagen
- Department of Medical Microbiology and Infectious Diseases, Canisius Wilhelmina Hospital, Weg door Jonkerbos 100, 6532 SZ Nijmegen, the Netherlands
| | - Jacques F Meis
- Department of Medical Microbiology and Infectious Diseases, Canisius Wilhelmina Hospital, Weg door Jonkerbos 100, 6532 SZ Nijmegen, the Netherlands; Department of Medical Microbiology, Radboud University Nijmegen Medical Centre, PO Box 9101, Nijmegen 6500 HB, the Netherlands; Department of Medical Microbiology and Infectious Diseases, Erasmus MC,'s-Gravendijkwal 230 3015 CE Rotterdam, the Netherlands
| | - Jos Houbraken
- CBS-KNAW Fungal Biodiversity Centre, Uppsalalaan 8, 3584 CT Utrecht, the Netherlands
| | - Robert A Samson
- CBS-KNAW Fungal Biodiversity Centre, Uppsalalaan 8, 3584 CT Utrecht, the Netherlands
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Tam EWT, Tsang CC, Lau SKP, Woo PCY. Polyketides, toxins and pigments in Penicillium marneffei. Toxins (Basel) 2015; 7:4421-36. [PMID: 26529013 PMCID: PMC4663511 DOI: 10.3390/toxins7114421] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Revised: 09/18/2015] [Accepted: 10/22/2015] [Indexed: 11/17/2022] Open
Abstract
Penicillium marneffei (synonym: Talaromyces marneffei) is the most important pathogenic thermally dimorphic fungus in China and Southeastern Asia. The HIV/AIDS pandemic, particularly in China and other Southeast Asian countries, has led to the emergence of P. marneffei infection as an important AIDS-defining condition. Recently, we published the genome sequence of P. marneffei. In the P. marneffei genome, 23 polyketide synthase genes and two polyketide synthase-non-ribosomal peptide synthase hybrid genes were identified. This number is much higher than those of Coccidioides immitis and Histoplasma capsulatum, important pathogenic thermally dimorphic fungi in the Western world. Phylogenetically, these polyketide synthase genes were distributed evenly with their counterparts found in Aspergillus species and other fungi, suggesting that polyketide synthases in P. marneffei did not diverge from lineage-specific gene duplication through a recent expansion. Gene knockdown experiments and ultra-high performance liquid chromatography-photodiode array detector/electrospray ionization-quadruple time of flight-mass spectrometry analysis confirmed that at least four of the polyketide synthase genes were involved in the biosynthesis of various pigments in P. marneffei, including melanin, mitorubrinic acid, mitorubrinol, monascorubrin, rubropunctatin, citrinin and ankaflavin, some of which were mycotoxins and virulence factors of the fungus.
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Affiliation(s)
- Emily W T Tam
- Department of Microbiology, The University of Hong Kong, Pokfulam, Hong Kong.
| | - Chi-Ching Tsang
- Department of Microbiology, The University of Hong Kong, Pokfulam, Hong Kong.
| | - Susanna K P Lau
- Department of Microbiology, The University of Hong Kong, Pokfulam, Hong Kong.
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Pokfulam, Hong Kong.
- Research Centre of Infection and Immunology, The University of Hong Kong, Pokfulam, Hong Kong.
- Carol Yu Centre for Infection, The University of Hong Kong, Pokfulam, Hong Kong.
| | - Patrick C Y Woo
- Department of Microbiology, The University of Hong Kong, Pokfulam, Hong Kong.
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Pokfulam, Hong Kong.
- Research Centre of Infection and Immunology, The University of Hong Kong, Pokfulam, Hong Kong.
- Carol Yu Centre for Infection, The University of Hong Kong, Pokfulam, Hong Kong.
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20
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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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The biosynthetic pathway for a thousand-year-old natural food colorant and citrinin in Penicillium marneffei. Sci Rep 2014; 4:6728. [PMID: 25335861 PMCID: PMC4205486 DOI: 10.1038/srep06728] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 09/08/2014] [Indexed: 12/17/2022] Open
Abstract
Monascorubrin and its derivatives are polyketides used as natural colorants for a wide range of food for more than one thousand years. Since the biosynthetic pathway for this ancient chemical compound is unknown and genome sequence unavailable for any Monascus species, monascorubrin production has relied on extraction from fungal cultures of Monascus species. In vitro synthesis and genetic manipulation are not possible. Here we report the polyketide gene cluster and pathway for monascorubrin biosynthesis in Penicillium marneffei, a diffusible red pigment-producing, thermal dimorphic fungus, taking advantage of available genome sequence and faster growth rate than Monascus species. We also documented that the red pigment of P. marneffei is a mixture of more than 16 chemical compounds, which are amino acid conjugates of monascorubrin and rubropunctatin, and showed that this polyketide gene cluster and pathway are also responsible for biosynthesis of ankaflavin and citrinin, a mycotoxin with nephrotoxic activity in mammals. The present study on elucidation of the biosynthetic pathway of monascorubrin is a proof-of-the-concept study that serves as a cornerstone for future studies on monascorubrin biosynthesis pathway dissection in Monascus species.
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Pattemore JA, Hane JK, Williams AH, Wilson BAL, Stodart BJ, Ash GJ. The genome sequence of the biocontrol fungus Metarhizium anisopliae and comparative genomics of Metarhizium species. BMC Genomics 2014; 15:660. [PMID: 25102932 PMCID: PMC4133081 DOI: 10.1186/1471-2164-15-660] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Accepted: 07/17/2014] [Indexed: 11/15/2022] Open
Abstract
Background Metarhizium anisopliae is an important fungal biocontrol agent of insect pests of agricultural crops. Genomics can aid the successful commercialization of biopesticides by identification of key genes differentiating closely related species, selection of virulent microbial isolates which are amenable to industrial scale production and formulation and through the reduction of phenotypic variability. The genome of Metarhizium isolate ARSEF23 was recently published as a model for M. anisopliae, however phylogenetic analysis has since re-classified this isolate as M. robertsii. We present a new annotated genome sequence of M. anisopliae (isolate Ma69) and whole genome comparison to M. robertsii (ARSEF23) and M. acridum (CQMa 102). Results Whole genome analysis of M. anisopliae indicates significant macrosynteny with M. robertsii but with some large genomic inversions. In comparison to M. acridum, the genome of M. anisopliae shares lower sequence homology. While alignments overall are co-linear, the genome of M. acridum is not contiguous enough to conclusively observe macrosynteny. Mating type gene analysis revealed both MAT1-1 and MAT1-2 genes present in M. anisopliae suggesting putative homothallism, despite having no known teleomorph, in contrast with the putatively heterothallic M. acridum isolate CQMa 102 (MAT1-2) and M. robertsii isolate ARSEF23 (altered MAT1-1). Repetitive DNA and RIP analysis revealed M. acridum to have twice the repetitive content of the other two species and M. anisopliae to be five times more RIP affected than M. robertsii. We also present an initial bioinformatic survey of candidate pathogenicity genes in M. anisopliae. Conclusions The annotated genome of M. anisopliae is an important resource for the identification of virulence genes specific to M. anisopliae and development of species- and strain- specific assays. New insight into the possibility of homothallism and RIP affectedness has important implications for the development of M. anisopliae as a biopesticide as it may indicate the potential for greater inherent diversity in this species than the other species. This could present opportunities to select isolates with unique combinations of pathogenicity factors, or it may point to instability in the species, a negative attribute in a biopesticide. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-660) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Julie A Pattemore
- Graham Centre for Agricultural Innovation, School of Agricultural and Wine Sciences, Charles Sturt University, Locked Bag 588, Wagga Wagga 2650, NSW, Australia.
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Abstract
The genus Talaromyces was described by Benjamin in 1955 as a sexual state of Penicillium that produces soft walled ascomata covered with interwoven hyphae. Phylogenetic information revealed that Penicillium subgenus Biverticillium and Talaromyces form a monophyletic clade distinct from the other Penicillium subgenera. Subsequently, in combination with the recent adoption of the one fungus one name concept, Penicillium subgenus Biverticillium was transferred to Talaromyces. At the time, the new combinations were made based only on phylogenetic information. As such, the aim of this study was to provide a monograph on Talaromyces applying a polyphasic species concept, including morphological, molecular and physiological characters. Based on an ITS, BenA and RPB2 multigene phylogeny, we propose a new sectional classification for the genus, placing the 88 accepted species into seven sections, named sections Bacillispori, Helici, Islandici, Purpurei, Subinflati, Talaromyces and Trachyspermi. We provide morphological descriptions for each of these species, as well as notes on their identification using morphology and DNA sequences. For molecular identification, BenA is proposed as a secondary molecular marker to the accepted ITS barcode for fungi.
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Affiliation(s)
- N. Yilmaz
- CBS-KNAW Fungal Biodiversity Centre, 3508 AD, Utrecht, The Netherlands
- Department of Biology, Utrecht University, Utrecht, The Netherlands
| | - C.M. Visagie
- CBS-KNAW Fungal Biodiversity Centre, 3508 AD, Utrecht, The Netherlands
| | - J. Houbraken
- CBS-KNAW Fungal Biodiversity Centre, 3508 AD, Utrecht, The Netherlands
| | - J.C. Frisvad
- Center for Microbial Biotechnology, Department of Systems Biology, Building 221, Technical University of Denmark, DK-2800, Kgs. Lyngby, Denmark
| | - R.A. Samson
- CBS-KNAW Fungal Biodiversity Centre, 3508 AD, Utrecht, The Netherlands
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24
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Abstract
Sexual reproduction is a pervasive attribute of eukaryotic species and is now recognized to occur in many clinically important human fungal pathogens. These fungi use sexual or parasexual strategies for various purposes that can have an impact on pathogenesis, such as the formation of drug-resistant isolates, the generation of strains with increased virulence or the modulation of interactions with host cells. In this Review, we examine the mechanisms regulating fungal sex and the consequences of these programmes for human disease.
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Lau SKP, Tse H, Chan JSY, Zhou AC, Curreem SOT, Lau CCY, Yuen KY, Woo PCY. Proteome profiling of the dimorphic fungus Penicillium marneffei extracellular proteins and identification of glyceraldehyde-3-phosphate dehydrogenase as an important adhesion factor for conidial attachment. FEBS J 2013; 280:6613-26. [PMID: 24128375 DOI: 10.1111/febs.12566] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Revised: 09/26/2013] [Accepted: 10/04/2013] [Indexed: 12/18/2022]
Abstract
Despite being the most important thermal dimorphic fungus causing systemic mycosis in Southeast Asia, the pathogenic mechanisms of Penicillium marneffei remain largely unknown. By comparing the extracellular proteomes of P. marneffei in mycelial and yeast phases, we identified 12 differentially expressed proteins among which glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and heat shock protein 60 (HSP60) were found to be upregulated in mycelial and yeast phases respectively. Based on previous findings in other pathogens, we hypothesized that these two extracellular proteins may be involved in adherence during P. marneffei-host interaction. Using inhibition assays with recombinant GAPDH (rGAPDH) proteins and anti-rGAPDH sera, we demonstrated that adhesion of P. marneffei conidia to fibronectin and laminin was inhibited by rGAPDH or rabbit anti-rGAPDH serum in a dose-dependent manner. Similarly, a dose-dependent inhibition of conidial adherence to A549 pneumocytes by rGAPDH or rabbit anti-rGAPDH serum was observed, suggesting that P. marneffei GAPDH can mediate binding of conidia to human extracellular matrix proteins and pneumocytes. However, HSP60 did not exhibit similar inhibition on conidia adherence, and neither GAPDH norHSP60 exhibited inhibition on adherence to J774 or THP-1 macrophage cell lines. This report demonstrates GAPDH as an adherence factor in P. marneffei by mediating conidia adherence to host bronchoalveolar epithelium during the early establishment phase of infection.
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Affiliation(s)
- Susanna K P Lau
- State Key Laboratory of Emerging Infectious Diseases, Research Centre of Infection and Immunology and Carol Yu Centre for Infection, University of Hong Kong, China; Department of Microbiology, University of Hong Kong, China
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26
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Lau SKP, Chow WN, Wong AYP, Yeung JMY, Bao J, Zhang N, Lok S, Woo PCY, Yuen KY. Identification of microRNA-like RNAs in mycelial and yeast phases of the thermal dimorphic fungus Penicillium marneffei. PLoS Negl Trop Dis 2013; 7:e2398. [PMID: 23991243 PMCID: PMC3749987 DOI: 10.1371/journal.pntd.0002398] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 07/19/2013] [Indexed: 01/16/2023] Open
Abstract
Background Penicillium marneffei is the most important thermal dimorphic fungus causing systemic mycosis in China and Southeast Asia. While miRNAs are increasingly recognized for their roles in post-transcriptional regulation of gene expression in animals and plants, miRNAs in fungi were less well studied and their potential roles in fungal dimorphism were largely unknown. Based on P. marneffei genome sequence, we hypothesize that miRNA-like RNAs (milRNAs) may be expressed in the dimorphic fungus. Methodology/Principal Findings We attempted to identify milRNAs in P. marneffei in both mycelial and yeast phase using high-throughput sequencing technology. Small RNAs were more abundantly expressed in mycelial than yeast phase. Sequence analysis revealed 24 potential milRNA candidates, including 17 candidates in mycelial and seven in yeast phase. Two genes, dcl-1 and dcl-2, encoding putative Dicer-like proteins and the gene, qde-2, encoding Argonaute-like protein, were identified in P. marneffei. Phylogenetic analysis showed that dcl-2 of P. marneffei was more closely related to the homologues in other thermal dimorphic pathogenic fungi than to Penicillium chrysogenum and Aspergillus spp., suggesting the co-evolution of dcl-2 among the thermal dimorphic fungi. Moreover, dcl-2 demonstrated higher mRNA expression levels in mycelial than yeast phase by 7 folds (P<0.001). Northern blot analysis confirmed the expression of two milRNAs, PM-milR-M1 and PM-milR-M2, only in mycelial phase. Using dcl-1KO, dcl-2KO, dclDKO and qde-2KO deletion mutants, we showed that the biogenesis of both milRNAs were dependent on dcl-2 but not dcl-1 or qde-2. The mRNA expression levels of three predicted targets of PM-milR-M1 were upregulated in knockdown strain PM-milR-M1KD, supporting regulatory function of milRNAs. Conclusions/Significance Our findings provided the first evidence for differential expression of milRNAs in different growth phases of thermal dimorphic fungi and shed light on the evolution of fungal proteins involved in milRNA biogenesis and possible role of post-transcriptional control in governing thermal dimorphism. Penicillium marneffei is the most important thermal dimorphic pathogenic fungus in Southeast Asia. Despite findings on diverse genes and mechanisms involved in dimorphic switching, the key to signally pathways governing the switch is still unknown. Since miRNAs are important regulatory molecules in eukaryotes, we attempt to define if miRNAs are expressed in different growth phases of P. marneffei. Using high-throughput sequencing, we identified 24 potential milRNA candidates in P. marneffei, which were more abundantly expressed in mycelial than yeast phase. Two genes, dcl-1 and dcl-2, encoding Dicer-like proteins and the gene, qde-2, encoding Argonaute-like protein, were also identified. Phylogenetic analysis showed that dcl-2 of P. marneffei was more closely related to the homologues in other thermal dimorphic pathogenic fungi than to Penicillium chrysogenum and Aspergillus spp.. dcl-2 demonstrated higher mRNA levels in mycelial than yeast phase. Northern blot analysis confirmed expression of two milRNAs, PM-milR-M1 and PM-milR-M2, only in mycelial phase, whose expression was dependent on dcl-2 but not dcl-1 or qde-2. The mRNA levels of three predicted targets of PM-milR-M1 were upregulated in knockdown strain PM-milR-M1KD, supporting its regulatory function. This study represents the first discovery of milRNAs in thermal dimorphic fungi, with differential expression in different growth phases.
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Affiliation(s)
- Susanna K. P. Lau
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China
- Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong, China
- Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Wang-Ngai Chow
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Annette Y. P. Wong
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Julian M. Y. Yeung
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
| | - Jessie Bao
- Genome Research Centre, The University of Hong Kong, Hong Kong, China
| | - Na Zhang
- Genome Research Centre, The University of Hong Kong, Hong Kong, China
| | - Si Lok
- Genome Research Centre, The University of Hong Kong, Hong Kong, China
| | - Patrick C. Y. Woo
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China
- Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong, China
- Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
- * E-mail: (PCYW); (KYY)
| | - Kwok-Yung Yuen
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong, China
- Research Centre of Infection and Immunology, The University of Hong Kong, Hong Kong, China
- Carol Yu Centre for Infection, The University of Hong Kong, Hong Kong, China
- Department of Microbiology, The University of Hong Kong, Hong Kong, China
- * E-mail: (PCYW); (KYY)
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Romance of the three domains: how cladistics transformed the classification of cellular organisms. Protein Cell 2013; 4:664-76. [PMID: 23873078 PMCID: PMC4875529 DOI: 10.1007/s13238-013-3050-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Accepted: 07/01/2013] [Indexed: 11/23/2022] Open
Abstract
Cladistics is a biological philosophy that uses genealogical relationship among species and an inferred sequence of divergence as the basis of classification. This review critically surveys the chronological development of biological classification from Aristotle through our postgenomic era with a central focus on cladistics. In 1957, Julian Huxley coined cladogenesis to denote splitting from subspeciation. In 1960, the English translation of Willi Hennig’s 1950 work, Systematic Phylogenetics, was published, which received strong opposition from pheneticists, such as numerical taxonomists Peter Sneath and Robert Sokal, and evolutionary taxonomist, Ernst Mayr, and sparked acrimonious debates in 1960–1980. In 1977–1990, Carl Woese pioneered in using small subunit rRNA gene sequences to delimitate the three domains of cellular life and established major prokaryotic phyla. Cladistics has since dominated taxonomy. Despite being compatible with modern microbiological observations, i.e. organisms with unusual phenotypes, restricted expression of characteristics and occasionally being uncultivable, increasing recognition of pervasiveness and abundance of horizontal gene transfer has challenged relevance and validity of cladistics. The mosaic nature of eukaryotic and prokaryotic genomes was also gradually discovered. In the mid-2000s, high-throughput and whole-genome sequencing became routine and complex geneologies of organisms have led to the proposal of a reticulated web of life. While genomics only indirectly leads to understanding of functional adaptations to ecological niches, computational modeling of entire organisms is underway and the gap between genomics and phenetics may soon be bridged. Controversies are not expected to settle as taxonomic classifications shall remain subjective to serve the human scientist, not the classified.
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Discovery of a sexual cycle in Aspergillus lentulus, a close relative of A. fumigatus. EUKARYOTIC CELL 2013; 12:962-9. [PMID: 23650087 PMCID: PMC3697472 DOI: 10.1128/ec.00040-13] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Aspergillus lentulus was described in 2005 as a new species within the A. fumigatus sensu lato complex. It is an opportunistic human pathogen causing invasive aspergillosis with high mortality rates, and it has been isolated from clinical and environmental sources. The species is morphologically nearly identical to A. fumigatus sensu stricto, and this similarity has resulted in their frequent misidentification. Comparative studies show that A. lentulus has some distinguishing growth features and decreased in vitro susceptibility to several antifungal agents, including amphotericin B and caspofungin. Similar to the once-presumed-asexual A. fumigatus, it has only been known to reproduce mitotically. However, we now show that A. lentulus has a heterothallic sexual breeding system. A PCR-based mating-type diagnostic detected isolates of either the MAT1-1 or MAT1-2 genotype, and examination of 26 worldwide clinical and environmental isolates revealed similar ratios of the two mating types (38% versus 62%, respectively). MAT1-1 and MAT1-2 idiomorph regions were analyzed, revealing the presence of characteristic alpha and high-mobility-group (HMG) domain genes, together with other more unusual features such as a MAT1-2-4 gene. We then demonstrated that A. lentulus possesses a functional sexual cycle with mature cleistothecia, containing heat-resistant ascospores, being produced after 3 weeks of incubation. Recombination was confirmed using molecular markers. However, isolates of A. lentulus failed to cross with highly fertile strains of A. fumigatus, demonstrating reproductive isolation between these sibling species. The discovery of the A. lentulus sexual stage has significant implications for the management of drug resistance and control of invasive aspergillosis associated with this emerging fungal pathogen.
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Identification of the mating-type (MAT) locus that controls sexual reproduction of Blastomyces dermatitidis. EUKARYOTIC CELL 2012; 12:109-17. [PMID: 23143684 DOI: 10.1128/ec.00249-12] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Blastomyces dermatitidis is a dimorphic fungal pathogen that primarily causes blastomycosis in the midwestern and northern United States and Canada. While the genes controlling sexual development have been known for a long time, the genes controlling sexual reproduction of B. dermatitidis (teleomorph, Ajellomyces dermatitidis) are unknown. We identified the mating-type (MAT) locus in the B. dermatitidis genome by comparative genomic approaches. The B. dermatitidis MAT locus resembles those of other dimorphic fungi, containing either an alpha-box (MAT1-1) or an HMG domain (MAT1-2) gene linked to the APN2, SLA2, and COX13 genes. However, in some strains of B. dermatitidis, the MAT locus harbors transposable elements (TEs) that make it unusually large compared to the MAT locus of other dimorphic fungi. Based on the MAT locus sequences of B. dermatitidis, we designed specific primers for PCR determination of the mating type. Two B. dermatitidis isolates of opposite mating types were cocultured on mating medium. Immature sexual structures were observed starting at 3 weeks of coculture, with coiled-hyphae-containing cleistothecia developing over the next 3 to 6 weeks. Genetic recombination was detected in potential progeny by mating-type determination, PCR-restriction fragment length polymorphism (PCR-RFLP), and random amplification of polymorphic DNA (RAPD) analyses, suggesting that a meiotic sexual cycle might have been completed. The F1 progeny were sexually fertile when tested with strains of the opposite mating type. Our studies provide a model for the evolution of the MAT locus in the dimorphic and closely related fungi and open the door to classic genetic analysis and studies on the possible roles of mating and mating type in infection and virulence.
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Woo PCY, Lam CW, Tam EWT, Leung CKF, Wong SSY, Lau SKP, Yuen KY. First discovery of two polyketide synthase genes for mitorubrinic acid and mitorubrinol yellow pigment biosynthesis and implications in virulence of Penicillium marneffei. PLoS Negl Trop Dis 2012; 6:e1871. [PMID: 23094121 PMCID: PMC3475676 DOI: 10.1371/journal.pntd.0001871] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2012] [Accepted: 09/02/2012] [Indexed: 11/20/2022] Open
Abstract
Background The genome of P. marneffei, the most important thermal dimorphic fungus causing respiratory, skin and systemic mycosis in China and Southeast Asia, possesses 23 polyketide synthase (PKS) genes and 2 polyketide synthase nonribosomal peptide synthase hybrid (PKS-NRPS) genes, which is of high diversity compared to other thermal dimorphic pathogenic fungi. We hypothesized that the yellow pigment in the mold form of P. marneffei could also be synthesized by one or more PKS genes. Methodology/Principal Findings All 23 PKS and 2 PKS-NRPS genes of P. marneffei were systematically knocked down. A loss of the yellow pigment was observed in the mold form of the pks11 knockdown, pks12 knockdown and pks11pks12 double knockdown mutants. Sequence analysis showed that PKS11 and PKS12 are fungal non-reducing PKSs. Ultra high performance liquid chromatography-photodiode array detector/electrospray ionization-quadruple time of flight-mass spectrometry (MS) and MS/MS analysis of the culture filtrates of wild type P. marneffei and the pks11 knockdown, pks12 knockdown and pks11pks12 double knockdown mutants showed that the yellow pigment is composed of mitorubrinic acid and mitorubrinol. The survival of mice challenged with the pks11 knockdown, pks12 knockdown and pks11pks12 double knockdown mutants was significantly better than those challenged with wild type P. marneffei (P<0.05). There was also statistically significant decrease in survival of pks11 knockdown, pks12 knockdown and pks11pks12 double knockdown mutants compared to wild type P. marneffei in both J774 and THP1 macrophages (P<0.05). Conclusions/Significance The yellow pigment of the mold form of P. marneffei is composed of mitorubrinol and mitorubrinic acid. This represents the first discovery of PKS genes responsible for mitorubrinol and mitorubrinic acid biosynthesis. pks12 and pks11 are probably responsible for sequential use in the biosynthesis of mitorubrinol and mitorubrinic acid. Mitorubrinol and mitorubrinic acid are virulence factors of P. marneffei by improving its intracellular survival in macrophages. Penicillium marneffei is the most important thermal dimorphic fungus causing respiratory, skin and systemic mycosis in China and Southeast Asia. Its genome possesses a large number of polyketide synthase (PKS) genes, which should be responsible for synthesis of secondary metabolites such as pigments, antibiotics and mycotoxins. Using state-of-the-art gene knockdown and ultra high performance liquid chromatography-photodiode array detector/electrospray ionization-quadruple time of flight-mass spectrometry technologies, we discovered that the yellow pigment of P. marneffei was composed of mitorubrinol and mitorubrinic acid and was synthesized by two PKS genes, named pks12 and pks11. This represents the first discovery of PKS genes responsible for mitorubrinol and mitorubrinic acid biosynthesis, in which pks12 and pks11 are probably responsible for sequential use in the biosynthesis of mitorubrinol and mitorubrinic acid. Using a mouse model and human and mouse macrophage cell line models for P. marneffei infection, we also discovered that mitorubrinol and mitorubrinic acid are virulence factors of P. marneffei by improving its intracellular survival in macrophages.
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Affiliation(s)
- Patrick C Y Woo
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong
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Henk DA, Shahar-Golan R, Devi KR, Boyce KJ, Zhan N, Fedorova ND, Nierman WC, Hsueh PR, Yuen KY, Sieu TPM, Kinh NV, Wertheim H, Baker SG, Day JN, Vanittanakom N, Bignell EM, Andrianopoulos A, Fisher MC. Clonality despite sex: the evolution of host-associated sexual neighborhoods in the pathogenic fungus Penicillium marneffei. PLoS Pathog 2012; 8:e1002851. [PMID: 23055919 PMCID: PMC3464222 DOI: 10.1371/journal.ppat.1002851] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Accepted: 06/25/2012] [Indexed: 12/04/2022] Open
Abstract
Molecular genetic approaches typically detect recombination in microbes regardless of assumed asexuality. However, genetic data have shown the AIDS-associated pathogen Penicillium marneffei to have extensive spatial genetic structure at local and regional scales, and although there has been some genetic evidence that a sexual cycle is possible, this haploid fungus is thought to be genetically, as well as morphologically, asexual in nature because of its highly clonal population structure. Here we use comparative genomics, experimental mixed-genotype infections, and population genetic data to elucidate the role of recombination in natural populations of P. marneffei. Genome wide comparisons reveal that all the genes required for meiosis are present in P. marneffei, mating type genes are arranged in a similar manner to that found in other heterothallic fungi, and there is evidence of a putatively meiosis-specific mutational process. Experiments suggest that recombination between isolates of compatible mating types may occur during mammal infection. Population genetic data from 34 isolates from bamboo rats in India, Thailand and Vietnam, and 273 isolates from humans in China, India, Thailand, and Vietnam show that recombination is most likely to occur across spatially and genetically limited distances in natural populations resulting in highly clonal population structure yet sexually reproducing populations. Predicted distributions of three different spatial genetic clusters within P. marneffei overlap with three different bamboo rat host distributions suggesting that recombination within hosts may act to maintain population barriers within P. marneffei.
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Affiliation(s)
- Daniel A Henk
- Department of Infectious Disease Epidemiology, Imperial College, Norfolk Place, London, United Kingdom.
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Abstract
Penicillium marneffei is the most important thermal dimorphic, pathogenic fungus endemic in China and Southeast Asia and is particularly important in HIV-positive patients. We report the 28,887,485-bp draft genome sequence of P. marneffei, which contains its complete mitochondrial genome, sexual cycle genes, a high diversity of Mp1p homologues, and polyketide synthase genes.
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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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Coelho MA, Gonçalves P, Sampaio JP. Evidence for maintenance of sex determinants but not of sexual stages in red yeasts, a group of early diverged basidiomycetes. BMC Evol Biol 2011; 11:249. [PMID: 21880139 PMCID: PMC3236058 DOI: 10.1186/1471-2148-11-249] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2011] [Accepted: 08/31/2011] [Indexed: 11/10/2022] Open
Abstract
Background The red yeasts are an early diverged group of basidiomycetes comprising sexual and asexual species. Sexuality is based on two compatible mating types and sexual identity is determined by MAT loci that encode homeodomain transcription factors, peptide pheromones and their receptors. The objective of the present study was to investigate the presence and integrity of MAT genes throughout the phylogenetic diversity of red yeasts belonging to the order Sporidiobolales. Results We surveyed 18 sexual heterothallic and self-fertile species and 16 asexual species. Functional pheromone receptor homologues (STE3.A1 and STE3.A2) were found in multiple isolates of most of the sexual and asexual species. For each of the two mating types, sequence comparisons with whole-genome data indicated that synteny tended to be conserved along the pheromone receptor region. For the homeodomain transcription factor, likelihood methods suggested that diversifying selection acting on the self/non-self recognition region promotes diversity in sexual species, while rapid evolution seems to be due to relaxed selection in asexual strains. Conclusions The majority of both sexual and asexual species of red yeasts have functional pheromone receptors and homeodomain homologues. This and the frequent existence of asexual strains within sexual species, makes the separation between sexual and asexual species imprecise. Events of loss of sexuality seem to be recent and frequent, but not uniformly distributed within the Sporidiobolales. Loss of sex could promote speciation by fostering the emergence of asexual lineages from an ancestral sexual stock, but does not seem to contribute to the generation of exclusively asexual lineages that persist for a long time.
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Affiliation(s)
- Marco A Coelho
- Centro de Recursos Microbiológicos (CREM), Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
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Woo PCY, Tam EWT, Chong KTK, Cai JJ, Tung ETK, Ngan AHY, Lau SKP, Yuen KY. High diversity of polyketide synthase genes and the melanin biosynthesis gene cluster in Penicillium marneffei. FEBS J 2010; 277:3750-8. [DOI: 10.1111/j.1742-4658.2010.07776.x] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Lee SC, Ni M, Li W, Shertz C, Heitman J. The evolution of sex: a perspective from the fungal kingdom. Microbiol Mol Biol Rev 2010; 74:298-340. [PMID: 20508251 PMCID: PMC2884414 DOI: 10.1128/mmbr.00005-10] [Citation(s) in RCA: 243] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Sex is shrouded in mystery. Not only does it preferentially occur in the dark for both fungi and many animals, but evolutionary biologists continue to debate its benefits given costs in light of its pervasive nature. Experimental studies of the benefits and costs of sexual reproduction with fungi as model systems have begun to provide evidence that the balance between sexual and asexual reproduction shifts in response to selective pressures. Given their unique evolutionary history as opisthokonts, along with metazoans, fungi serve as exceptional models for the evolution of sex and sex-determining regions of the genome (the mating type locus) and for transitions that commonly occur between outcrossing/self-sterile and inbreeding/self-fertile modes of reproduction. We review here the state of the understanding of sex and its evolution in the fungal kingdom and also areas where the field has contributed and will continue to contribute to illuminating general principles and paradigms of sexual reproduction.
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Affiliation(s)
- Soo Chan Lee
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina 27710
| | - Min Ni
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina 27710
| | - Wenjun Li
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina 27710
| | - Cecelia Shertz
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina 27710
| | - Joseph Heitman
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina 27710
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Woo PCY, Lau SKP, Ngan AHY, Tung ETK, Leung SY, To KKW, Cheng VCC, Yuen KY. Lichtheimia hongkongensis sp. nov., a novel Lichtheimia spp. associated with rhinocerebral, gastrointestinal, and cutaneous mucormycosis. Diagn Microbiol Infect Dis 2010; 66:274-84. [PMID: 20159375 DOI: 10.1016/j.diagmicrobio.2009.10.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2009] [Revised: 09/26/2009] [Accepted: 10/07/2009] [Indexed: 11/28/2022]
Abstract
Three thermotolerant "Absidia-like" isolates with unique morphologic characteristics, recovered from nasopharyngeal swab of a liver transplant recipient, gastric biopsy of a renal transplant recipient, and skin biopsy of a man with burn, respectively, were characterized. Microscopic examination showed nonseptate hyphae with highly branched sporangiophores. Uniquely, most side branches were circinate, and abundant pleomorphic giant cells with fingerlike projections were observed, characteristics absent from other Absidia/Lichtheimia spp. ITS1-5.8S-ITS2 rRNA gene cluster, partial EF1alpha gene, and partial beta-actin gene sequencing showed that the 3 strains formed a distinct cluster, most closely related to, but distinct from, Lichtheimia corymbifera, Lichtheimia blakesleeana, and Lichtheimia hyalospora. Based on the morphologic and genotypic characteristics, we propose a new species, Lichtheimia hongkongensis sp. nov., to describe this fungus, which caused rhinocerebral, gastrointestinal, and cutaneous mucormycosis, respectively, in 3 patients. A significant proportion of L. corymbifera associated with mucormycosis reported may be L. hongkongensis.
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Affiliation(s)
- Patrick C Y Woo
- State Key Laboratory of Emerging Infectious Diseases, The University of Hong Kong, Hong Kong.
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López-Villavicencio M, Aguileta G, Giraud T, de Vienne DM, Lacoste S, Couloux A, Dupont J. Sex in Penicillium: combined phylogenetic and experimental approaches. Fungal Genet Biol 2010; 47:693-706. [PMID: 20460164 DOI: 10.1016/j.fgb.2010.05.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2010] [Revised: 04/16/2010] [Accepted: 05/06/2010] [Indexed: 12/28/2022]
Abstract
We studied the mode of reproduction and its evolution in the fungal subgenus Penicillium Biverticillium using phylogenetic and experimental approaches. We sequenced mating type (MAT) genes and nuclear DNA fragments in sexual and putatively asexual species. Examination of the concordance between individual trees supported the recognition of the morphological species. MAT genes were detected in two putatively asexual species and were found to evolve mostly under purifying selection, although high substitution rates were detected at some sites in some clades. The first steps of sexual reproduction could be induced under controlled conditions in one of the two species, although no mature cleistothecia were produced. Altogether, these findings suggest that the asexual Penicillium species may have lost sex only very recently and/or that the MAT genes are involved in other functions. An ancestral state reconstruction analysis indicated several events of putative sex loss in the genus. Alternatively, it is possible that the supposedly asexual Penicillium species may have retained a cryptic sexual stage.
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Affiliation(s)
- M López-Villavicencio
- Origine, Structure, Evolution de la Diversité, UMR 7205 CNRS-MNHN, Muséum national d'histoire naturelle, CP39, 57 rue Cuvier, 75231 Paris Cedex 05, France.
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Abstract
Human fungal pathogens are associated with diseases ranging from dandruff and skin colonization to invasive bloodstream infections. The major human pathogens belong to the Candida, Aspergillus, and Cryptococcus clades, and infections have high and increasing morbidity and mortality. Many human fungal pathogens were originally assumed to be asexual. However, recent advances in genome sequencing, which revealed that many species have retained the genes required for the sexual machinery, have dramatically influenced our understanding of the biology of these organisms. Predictions of a rare or cryptic sexual cycle have been supported experimentally for some species. Here, I examine the evidence that human pathogens reproduce sexually. The evolution of the mating-type locus in ascomycetes (including Candida and Aspergillus species) and basidiomycetes (Malassezia and Cryptococcus) is discussed. I provide an overview of how sex is suppressed in different species and discuss the potential associations with pathogenesis.
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Internal transcribed spacer region sequence heterogeneity in Rhizopus microsporus: implications for molecular diagnosis in clinical microbiology laboratories. J Clin Microbiol 2009; 48:208-14. [PMID: 19906897 DOI: 10.1128/jcm.01750-09] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Although internal transcribed spacer region (ITS) sequence heterogeneity has been reported in a few fungal species, it has very rarely been reported in pathogenic fungi and has never been described in Mucorales, causes of the highly fatal mucormycosis. In a recent outbreak investigation of intestinal mucormycosis due to Rhizopus microsporus infection in patients with hematological malignancies, PCR of the ITS of four of the 28 R. microsporus strains, P11, P12, D3-1, and D4-1, showed thick bands at about 700 bp. Direct sequencing of the purified bands showed frequent double peaks along all of the sequence traces and occasional triple peaks for P12, D3-1, and D4-1. The thick bands of the four R. microsporus strains were purified and cloned. Sequencing of 10 clones for each strain revealed two different ITS sequences for P11 and three different ITS sequences for P12, D3-1, and D4-1. Variations in ITS sequence among the different ribosomal DNA (rDNA) operons in the same strain were observed in only ITS1 and ITS2 and not the 5.8S rDNA region. One copy of P11, P12, and D4-1, respectively, and one copy of P11, P12, D3-1, and D4-1, respectively, showed identical sequences. This represents the first evidence of ITS sequence heterogeneity in Mucorales. ITS sequence heterogeneity is an obstacle to molecular identification and genotyping of fungi in clinical microbiology laboratories. When thick bands and double peaks are observed during PCR sequencing of a gene target, such a strain should be sent to reference laboratories proficient in molecular technologies for further identification and/or genotyping.
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Organization and evolutionary trajectory of the mating type (MAT) locus in dermatophyte and dimorphic fungal pathogens. EUKARYOTIC CELL 2009; 9:46-58. [PMID: 19880755 DOI: 10.1128/ec.00259-09] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Sexual reproduction in fungi is governed by a specialized genomic region, the mating type (MAT) locus, whose gene identity, organization, and complexity are diverse. We identified the MAT locus of five dermatophyte fungal pathogens (Microsporum gypseum, Microsporum canis, Trichophyton equinum, Trichophyton rubrum, and Trichophyton tonsurans) and a dimorphic fungus, Paracoccidioides brasiliensis, and performed phylogenetic analyses. The identified MAT locus idiomorphs of M. gypseum control cell type identity in mating assays, and recombinant progeny were produced. Virulence tests in Galleria mellonella larvae suggest the two mating types of M. gypseum may have equivalent virulence. Synteny analysis revealed common features of the MAT locus shared among these five dermatophytes: namely, a small size ( approximately 3 kb) and a novel gene arrangement. The SLA2, COX13, and APN2 genes, which flank the MAT locus in other Ascomycota are instead linked on one side of the dermatophyte MAT locus. In addition, the transcriptional orientations of the APN2 and COX13 genes are reversed compared to the dimorphic fungi Histoplasma capsulatum, Coccidioides immitis, and Coccidioides posadasii. A putative transposable element, pogo, was found to have inserted in the MAT1-2 idiomorph of one P. brasiliensis strain but not others. In conclusion, the evolution of the MAT locus of the dermatophytes and dimorphic fungi from the last common ancestor has been punctuated by both gene acquisition and expansion, and asymmetric gene loss. These studies further support a foundation to develop molecular and genetic tools for dermatophyte and dimorphic human fungal pathogens.
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Abstract
Sinopulmonary and rhinocerebral zygomycosis has been increasingly found in patients with hematological malignancies and bone marrow transplantation, but intestinal zygomycosis remains very rare in the literature. We investigated an outbreak of intestinal infection due to Rhizopus microsporus in 12 patients on treatment for hematological malignancies over a period of 6 months in a teaching hospital. The intake of allopurinol during hospitalization (P < 0.001) and that of commercially packaged ready-to-eat food items in the preceding 2 weeks (P < 0.001) were found to be independently significant risk factors for the development of intestinal zygomycosis. A total of 709 specimens, including 378 environmental and air samples, 181 food samples, and 150 drug samples, were taken for fungal culture. Among them, 16 samples of allopurinol tablets, 3 prepackaged ready-to-eat food items, and 1 pair of wooden chopsticks were positive for Rhizopus microsporus, which was confirmed by ITS1-5.8S-ITS2 rRNA gene cluster (internal transcribed spacer [ITS]) sequencing. The mean viable fungal counts of allopurinol obtained from wards and pharmacy were 4.22 x 10(3) CFU/g of tablet (range, 3.07 x 10(3) to 5.48 x 10(3)) and 3.24 x 10(3) CFU/g of tablet (range, 2.68 x 10(3) to 3.72 x 10(3)), respectively, which were much higher than the mean count of 2 x 10(2) CFU/g of food. Phylogenetic analysis by ITS sequencing showed multiple clones from isolates of contaminated allopurinol tablets and ready-to-eat food, of which some were identical to patients' isolates, and with one isolate in the cornstarch used as an excipient for manufacture of this drug. We attempted to type the isolates by random amplification of polymorphic DNA analysis, with limited evidence of clonal distribution. The primary source of the contaminating fungus was likely to be the cornstarch used in the manufacturing of allopurinol tablets or ready-to-eat food. Rhizopus microsporus is thermotolerant and can multiply even at 50 degrees C. The long holding time of the intermediates during the manufacturing process of allopurinol amplified the fungal load. Microbiological monitoring of drugs manufactured for highly immunosuppressed patients should be considered.
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Schurko AM, Neiman M, Logsdon JM. Signs of sex: what we know and how we know it. Trends Ecol Evol 2009; 24:208-17. [DOI: 10.1016/j.tree.2008.11.010] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2008] [Revised: 11/18/2008] [Accepted: 11/20/2008] [Indexed: 12/26/2022]
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Asexual cephalosporin C producer Acremonium chrysogenum carries a functional mating type locus. Appl Environ Microbiol 2008; 74:6006-16. [PMID: 18689517 DOI: 10.1128/aem.01188-08] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Acremonium chrysogenum, the fungal producer of the pharmaceutically relevant beta-lactam antibiotic cephalosporin C, is classified as asexual because no direct observation of mating or meiosis has yet been reported. To assess the potential of A. chrysogenum for sexual reproduction, we screened an expressed sequence tag library from A. chrysogenum for the expression of mating type (MAT) genes, which are the key regulators of sexual reproduction. We identified two putative mating type genes that are homologues of the alpha-box domain gene, MAT1-1-1 and MAT1-1-2, encoding an HPG domain protein defined by the presence of the three invariant amino acids histidine, proline, and glycine. In addition, cDNAs encoding a putative pheromone receptor and pheromone-processing enzymes, as well as components of a pheromone response pathway, were found. Moreover, the entire A. chrysogenum MAT1-1 (AcMAT1-1) gene and regions flanking the MAT region were obtained from a genomic cosmid library, and sequence analysis revealed that in addition to AcMAT1-1-1 and AcMAT1-1-2, the AcMAT1-1 locus comprises a third mating type gene, AcMAT1-1-3, encoding a high-mobility-group domain protein. The alpha-box domain sequence of AcMAT1-1-1 was used to determine the phylogenetic relationships of A. chrysogenum to other ascomycetes. To determine the functionality of the AcMAT1-1 locus, the entire MAT locus was transferred into a MAT deletion strain of the heterothallic ascomycete Podospora anserina (the PaDeltaMAT strain). After fertilization with a P. anserina MAT1-2 (MAT(+)) strain, the corresponding transformants developed fruiting bodies with mature ascospores. Thus, the results of our functional analysis of the AcMAT1-1 locus provide strong evidence to hypothesize a sexual cycle in A. chrysogenum.
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Hoff B, Pöggeler S, Kück U. Eighty years after its discovery, Fleming's Penicillium strain discloses the secret of its sex. EUKARYOTIC CELL 2008; 7:465-70. [PMID: 18223118 PMCID: PMC2268512 DOI: 10.1128/ec.00430-07] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2007] [Accepted: 01/16/2008] [Indexed: 12/29/2022]
Abstract
Eighty years ago, Alexander Fleming discovered antibacterial activity in the asexual mold Penicillium, and the strain he studied later was replaced by an overproducing isolate still used for penicillin production today. Using a heterologous PCR approach, we show that these strains are of opposite mating types and that both have retained transcriptionally expressed pheromone and pheromone receptor genes required for sexual reproduction. This discovery extends options for industrial strain improvement programs using conventional genetical approaches.
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Affiliation(s)
- Birgit Hoff
- Ruhr-Universität Bochum, Lehrstuhl für Allgemeine und Molekulare Botanik, Universitätsstr. 150, 44780 Bochum, Germany
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Cooper CR, Vanittanakom N. Insights into the pathogenicity of Penicillium marneffei. Future Microbiol 2008; 3:43-55. [PMID: 18230033 DOI: 10.2217/17460913.3.1.43] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Penicillium marneffei is a significant pathogen of AIDS patients in Southeast Asia. This fungus is unique in that it is the only dimorphic member of the genus. Pathogenesis of P. marneffei requires the saprobic mold form to undergo a morphological change upon tissue invasion. The in vivo form of this fungus reproduces as a fission yeast that capably evades the host immune system. The processes that control these morphological changes, better termed as phase transition, can be replicated in vitro by incubation of the mold form at 37 degrees C. The unidentified molecular mechanisms regulating phase transition in this fungus are now being uncovered using modern methodologies and novel strategies. A better comprehension of these underlying regulatory pathways will provide insight into eukaryotic cellular development as well as the potential factors responsible for infections caused by P. marneffei and other fungi. Such knowledge may lead to better chemotherapeutic interventions of fungal diseases.
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Affiliation(s)
- Chester R Cooper
- Department of Biological Sciences, Youngstown State University, 1 University Plaza, Youngstown, OH 44555, USA.
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Sexual reproduction as the cause of heat resistance in the food spoilage fungus Byssochlamys spectabilis (anamorph Paecilomyces variotii). Appl Environ Microbiol 2008; 74:1613-9. [PMID: 18192427 DOI: 10.1128/aem.01761-07] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Paecilomyces variotii is a common cosmopolitan species that is able to spoil various food- and feedstuffs and is frequently encountered in heat-treated products. However, isolates from heat-treated products rarely form ascospores. In this study we examined by using molecular techniques and mating tests whether this species can undergo a sexual cycle and form ascospores. The population structure of this species was examined by analyzing the nuclear ribosomal internal transcribed spacer 1 (ITS1) and ITS2 and the 5.8S rRNA gene, as well as partial beta-tubulin, actin, and calmodulin gene sequences. Phylogenetic analyses revealed that P. variotii is a highly variable species. Partition homogeneity tests revealed that P. variotii has a recombining population structure. In addition to sequence analyses, mating experiments indicated that P. variotii is able to form ascomata and ascospores in culture in a heterothallic manner. The distribution of MAT1-1 and MAT1-2 genes showed a 1:1 ratio in the progeny of the mating experiments. From the sequence analyses and mating data we conclude that P. variotii is the anamorph of Talaromyces spectabilis and that it has a biallelic heterothallic mating system. Since Paecilomyces sensu stricto anamorphs group within Byssochlamys, a new combination Byssochlamys spectabilis is proposed.
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Woo PCY, Lau CCY, Chong KTK, Tse H, Tsang DNC, Lee RA, Tse CWS, Que TL, Chung LMW, Ngan AHY, Hui WT, Wong SSY, Lau SKP, Yuen KY. MP1 homologue-based multilocus sequence system for typing the pathogenic fungus Penicillium marneffei: a novel approach using lineage-specific genes. J Clin Microbiol 2007; 45:3647-54. [PMID: 17881546 PMCID: PMC2168507 DOI: 10.1128/jcm.00619-07] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A highly reproducible and discriminative typing system is essential for better understanding of the epidemiology of Penicillium marneffei, the most important thermal dimorphic fungus causing respiratory, skin, and systemic mycosis in Southeast Asia. The sequences of 11 housekeeping genes were identical among 10 strains of P. marneffei, but those of MP1 and its 13 homologues, a novel superfamily of mannoproteins in the subdivision Pezizomycotina of Ascomycetes, mostly species of Penicillium and Aspergillus, showed significant variations. Therefore, a multilocus sequence typing (MLST) system for P. marneffei was constructed using MP1 (549 bp) and the four of its homologues (MPLP4 [337 bp], MPLP7 [347 bp], MPLP10 [546 bp], and MPLP13 [422 bp]) that showed the greatest variations. Among the 2,201 bp of the five loci, 183 polymorphic sites were observed in 44 strains of P. marneffei. The median number of alleles at each locus was five (range, 5 [MPLP4, MPLP7, and MPLP13] to 15 [MPLP10]). Four of the five genes had nonsynonymous substitution/synonymous substitution (d(n)/d(s)) ratios of >1. A total of 35 different sequence types (STs) were assigned to the 44 P. marneffei isolates, with 28 of the 35 STs identified only once. The discriminatory power was 0.9884. MP1 and its homologues were better than housekeeping genes for MLST in P. marneffei. Due to their more rapid evolutionary rates, lineage-specific genes may be better candidates than housekeeping genes for sequence-based typing, especially in microbes that evolve slowly or have evolved recently.
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Affiliation(s)
- Patrick C Y Woo
- State Key Laboratory of Emerging Infectious Diseases, Department of Microbiology, The University of Hong Kong, University Pathology Building, Queen Mary Hospital, Hong Kong
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Nichols CB, Perfect ZH, Alspaugh JA. A Ras1-Cdc24 signal transduction pathway mediates thermotolerance in the fungal pathogen Cryptococcus neoformans. Mol Microbiol 2007; 63:1118-30. [PMID: 17233829 DOI: 10.1111/j.1365-2958.2006.05566.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Pathogenic microorganisms must precisely regulate morphogenesis to survive and proliferate within an infected host. This regulation is often controlled by conserved signal transduction pathways that direct morphological changes in varied species. One such pathway, whose components include Ras proteins and the PAK kinase Ste20, allows the human fungal pathogen Cryptococcus neoformans to grow at high temperature. Previously, we found that Ras1 signalling is required for differentiation, thermotolerance and pathogenesis in C. neoformans. We show here that the guanine nucleotide exchange factor Cdc24 is a Ras1 effector in C. neoformans to mediate the ability of this fungus to grow at high temperature and to cause disease. In addition, we provide evidence that the Ras1-Cdc24 signalling cascade functions specifically through one of the three Cdc42/Rac1 homologues in C. neoformans. In conclusion, our studies illustrate how components of conserved signalling cascades can be specialized for different downstream functions, such as pathogenesis.
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Affiliation(s)
- Connie B Nichols
- Department of Medicine, Duke University Medical CenterDurham, NC 27710, USA
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