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Sokołowska B, Orłowska M, Okrasińska A, Piłsyk S, Pawłowska J, Muszewska A. What can be lost? Genomic perspective on the lipid metabolism of Mucoromycota. IMA Fungus 2023; 14:22. [PMID: 37932857 PMCID: PMC10629195 DOI: 10.1186/s43008-023-00127-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2022] [Accepted: 10/23/2023] [Indexed: 11/08/2023] Open
Abstract
Mucoromycota is a phylum of early diverging fungal (EDF) lineages, of mostly plant-associated terrestrial fungi. Some strains have been selected as promising biotechnological organisms due to their ability to produce polyunsaturated fatty acids and efficient conversion of nutrients into lipids. Others get their lipids from the host plant and are unable to produce even the essential ones on their own. Following the advancement in EDF genome sequencing, we carried out a systematic survey of lipid metabolism protein families across different EDF lineages. This enabled us to explore the genomic basis of the previously documented ability to produce several types of lipids within the fungal tree of life. The core lipid metabolism genes showed no significant diversity in distribution, however specialized lipid metabolic pathways differed in this regard among different fungal lineages. In total 165 out of 202 genes involved in lipid metabolism were present in all tested fungal lineages, while remaining 37 genes were found to be absent in some of fungal lineages. Duplications were observed for 69 genes. For the first time we demonstrate that ergosterol is not being produced by several independent groups of plant-associated fungi due to the losses of different ERG genes. Instead, they possess an ancestral pathway leading to the synthesis of cholesterol, which is absent in other fungal lineages. The lack of diacylglycerol kinase in both Mortierellomycotina and Blastocladiomycota opens the question on sterol equilibrium regulation in these organisms. Early diverging fungi retained most of beta oxidation components common with animals including Nudt7, Nudt12 and Nudt19 pointing at peroxisome divergence in Dikarya. Finally, Glomeromycotina and Mortierellomycotina representatives have a similar set of desaturases and elongases related to the synthesis of complex, polyunsaturated fatty acids pointing at an ancient expansion of fatty acid metabolism currently being explored by biotechnological studies.
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Affiliation(s)
- Blanka Sokołowska
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5A, 02-106, Warsaw, Poland
- Faculty of Biology, Biological and Chemical Research Centre, Institute of Evolutionary Biology, University of Warsaw, Zwirki i Wigury 101, 02-089, Warsaw, Poland
| | - Małgorzata Orłowska
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5A, 02-106, Warsaw, Poland
- Faculty of Biology, Biological and Chemical Research Centre, Institute of Evolutionary Biology, University of Warsaw, Zwirki i Wigury 101, 02-089, Warsaw, Poland
| | - Alicja Okrasińska
- Faculty of Biology, Biological and Chemical Research Centre, Institute of Evolutionary Biology, University of Warsaw, Zwirki i Wigury 101, 02-089, Warsaw, Poland
| | - Sebastian Piłsyk
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5A, 02-106, Warsaw, Poland
| | - Julia Pawłowska
- Faculty of Biology, Biological and Chemical Research Centre, Institute of Evolutionary Biology, University of Warsaw, Zwirki i Wigury 101, 02-089, Warsaw, Poland
| | - Anna Muszewska
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawinskiego 5A, 02-106, Warsaw, Poland.
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Wilson AM, Coetzee MPA, Wingfield MJ, Wingfield BD. Needles in fungal haystacks: Discovery of a putative a-factor pheromone and a unique mating strategy in the Leotiomycetes. PLoS One 2023; 18:e0292619. [PMID: 37824487 PMCID: PMC10569646 DOI: 10.1371/journal.pone.0292619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Accepted: 09/25/2023] [Indexed: 10/14/2023] Open
Abstract
The Leotiomycetes is a hugely diverse group of fungi, accommodating a wide variety of important plant and animal pathogens, ericoid mycorrhizal fungi, as well as producers of antibiotics. Despite their importance, the genetics of these fungi remain relatively understudied, particularly as they don't include model taxa. For example, sexual reproduction and the genetic mechanisms that underly this process are poorly understood in the Leotiomycetes. We exploited publicly available genomic and transcriptomic resources to identify genes of the mating-type locus and pheromone response pathway in an effort to characterize the mating strategies and behaviors of 124 Leotiomycete species. Our analyses identified a putative a-factor mating pheromone in these species. This significant finding represents the first identification of this gene in Pezizomycotina species outside of the Sordariomycetes. A unique mating strategy was also discovered in Lachnellula species that appear to have lost the need for the primary MAT1-1-1 protein. Ancestral state reconstruction enabled the identification of numerous transitions between homothallism and heterothallism in the Leotiomycetes and suggests a heterothallic ancestor for this group. This comprehensive catalog of mating-related genes from such a large group of fungi provides a rich resource from which in-depth, functional studies can be conducted in these economically and ecologically important species.
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Affiliation(s)
- Andi M. Wilson
- Department of Biochemistry, Genetics & Microbiology, Forestry & Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Martin P. A. Coetzee
- Department of Biochemistry, Genetics & Microbiology, Forestry & Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Michael J. Wingfield
- Department of Biochemistry, Genetics & Microbiology, Forestry & Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
| | - Brenda D. Wingfield
- Department of Biochemistry, Genetics & Microbiology, Forestry & Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
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Wang Q, Chen Y, Yang Q, Zhao J, Feng L, Wang M. SR5AL serves as a key regulatory gene in lycopene biosynthesis by Blakeslea trispora. Microb Cell Fact 2022; 21:126. [PMID: 35752808 PMCID: PMC9233402 DOI: 10.1186/s12934-022-01853-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2021] [Accepted: 06/16/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Trisporic acids are considered to be key regulators of carotenoid biosynthesis and sexual reproduction in zygomycetes, but the mechanisms underlying this regulation have not been fully elucidated. RESULTS In this study, the relationships between trisporic acids and lycopene synthesis were investigated in Blakeslea trispora. The lycopene concentration in single fermentation by the (-) strain with the addition of 24 μg/L trisporic acids was slightly higher than that observed in mated fermentation. After transcriptomic analysis, a steroid 5α-reductase-like gene, known as SR5AL in B. trispora, was first reported. 5α-Reductase inhibitors reduced lycopene biosynthesis and downregulated the expression of sex determination and carotenoid biosynthesis genes. Overexpression of the SR5AL gene upregulated these genes, regardless of whether trisporic acids were added. CONCLUSION These findings indicated that the SR5AL gene is a key gene associated with the response to trisporic acids.
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Affiliation(s)
- Qiang Wang
- College of Life Sciences, Henan Normal University, Xinxiang, 453007, China.,Henan International Joint Laboratory of Agricultural Microbial Ecology and Technology (Henan Provincial Department of Science and Technology), Henan Normal University, Xinxiang, 453007, China
| | - Yulong Chen
- College of Life Sciences, Henan Normal University, Xinxiang, 453007, China
| | - Qingxiang Yang
- College of Life Sciences, Henan Normal University, Xinxiang, 453007, China. .,Henan International Joint Laboratory of Agricultural Microbial Ecology and Technology (Henan Provincial Department of Science and Technology), Henan Normal University, Xinxiang, 453007, China.
| | - Jihong Zhao
- College of Life Sciences, Henan Normal University, Xinxiang, 453007, China.,Henan International Joint Laboratory of Agricultural Microbial Ecology and Technology (Henan Provincial Department of Science and Technology), Henan Normal University, Xinxiang, 453007, China
| | - Lingran Feng
- College of Life Sciences, Henan Normal University, Xinxiang, 453007, China
| | - Min Wang
- College of Life Sciences, Henan Normal University, Xinxiang, 453007, China
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Carotenoids and Their Biosynthesis in Fungi. Molecules 2022; 27:molecules27041431. [PMID: 35209220 PMCID: PMC8879039 DOI: 10.3390/molecules27041431] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 02/16/2022] [Accepted: 02/16/2022] [Indexed: 12/04/2022] Open
Abstract
Carotenoids represent a class of pigmented terpenoids. They are distributed in all taxonomic groups of fungi. Most of the fungal carotenoids differ in their chemical structures to those from other organisms. The general function of carotenoids in heterotrophic organisms is protection as antioxidants against reactive oxygen species generated by photosensitized reactions. Furthermore, carotenoids are metabolized to apocarotenoids by oxidative cleavage. This review presents the current knowledge on fungal-specific carotenoids, their occurrence in different taxonomic groups, and their biosynthesis and conversion into trisporic acids. The outline of the different pathways was focused on the reactions and genes involved in not only the known pathways, but also suggested the possible mechanisms of reactions, which may occur in several non-characterized pathways in different fungi. Finally, efforts and strategies for genetic engineering to enhance or establish pathways for the production of various carotenoids in carotenogenic or non-carotenogenic yeasts were highlighted, addressing the most-advanced producers of each engineered yeast, which offered the highest biotechnological potentials as production systems.
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Muszewska A, Okrasińska A, Steczkiewicz K, Drgas O, Orłowska M, Perlińska-Lenart U, Aleksandrzak-Piekarczyk T, Szatraj K, Zielenkiewicz U, Piłsyk S, Malc E, Mieczkowski P, Kruszewska JS, Bernat P, Pawłowska J. Metabolic Potential, Ecology and Presence of Associated Bacteria Is Reflected in Genomic Diversity of Mucoromycotina. Front Microbiol 2021; 12:636986. [PMID: 33679672 PMCID: PMC7928374 DOI: 10.3389/fmicb.2021.636986] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Accepted: 01/25/2021] [Indexed: 11/13/2022] Open
Abstract
Mucoromycotina are often considered mainly in pathogenic context but their biology remains understudied. We describe the genomes of six Mucoromycotina fungi representing distant saprotrophic lineages within the subphylum (i.e., Umbelopsidales and Mucorales). We selected two Umbelopsis isolates from soil (i.e., U. isabellina, U. vinacea), two soil-derived Mucor isolates (i.e., M. circinatus, M. plumbeus), and two Mucorales representatives with extended proteolytic activity (i.e., Thamnidium elegans and Mucor saturninus). We complement computational genome annotation with experimental characteristics of their digestive capabilities, cell wall carbohydrate composition, and extensive total lipid profiles. These traits inferred from genome composition, e.g., in terms of identified encoded enzymes, are in accordance with experimental results. Finally, we link the presence of associated bacteria with observed characteristics. Thamnidium elegans genome harbors an additional, complete genome of an associated bacterium classified to Paenibacillus sp. This fungus displays multiple altered traits compared to the remaining isolates, regardless of their evolutionary distance. For instance, it has expanded carbon assimilation capabilities, e.g., efficiently degrades carboxylic acids, and has a higher diacylglycerol:triacylglycerol ratio and skewed phospholipid composition which suggests a more rigid cellular membrane. The bacterium can complement the host enzymatic capabilities, alter the fungal metabolism, cell membrane composition but does not change the composition of the cell wall of the fungus. Comparison of early-diverging Umbelopsidales with evolutionary younger Mucorales points at several subtle differences particularly in their carbon source preferences and encoded carbohydrate repertoire. Nevertheless, all tested Mucoromycotina share features including the ability to produce 18:3 gamma-linoleic acid, use TAG as the storage lipid and have fucose as a cell wall component.
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Affiliation(s)
- Anna Muszewska
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Alicja Okrasińska
- Institute of Evolutionary Biology, Faculty of Biology, Biological and Chemical Research Centre, University of Warsaw, Warsaw, Poland
| | - Kamil Steczkiewicz
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Olga Drgas
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Małgorzata Orłowska
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | | | | | - Katarzyna Szatraj
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Urszula Zielenkiewicz
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Sebastian Piłsyk
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Ewa Malc
- High Throughput Sequencing Facility of UNC, Chapel Hill, NC, United States
| | - Piotr Mieczkowski
- High Throughput Sequencing Facility of UNC, Chapel Hill, NC, United States
| | - Joanna S. Kruszewska
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw, Poland
| | - Przemysław Bernat
- Department of Industrial Microbiology and Biotechnology, Faculty of Biology and Environmental Protection, University of Łódź, Łódź, Poland
| | - Julia Pawłowska
- Institute of Evolutionary Biology, Faculty of Biology, Biological and Chemical Research Centre, University of Warsaw, Warsaw, Poland
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Mateus ID, Rojas EC, Savary R, Dupuis C, Masclaux FG, Aletti C, Sanders IR. Coexistence of genetically different Rhizophagus irregularis isolates induces genes involved in a putative fungal mating response. THE ISME JOURNAL 2020; 14:2381-2394. [PMID: 32514118 PMCID: PMC7490403 DOI: 10.1038/s41396-020-0694-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 05/16/2020] [Accepted: 05/27/2020] [Indexed: 02/07/2023]
Abstract
Arbuscular mycorrhizal fungi (AMF) are of great ecological importance because of their effects on plant growth. Closely related genotypes of the same AMF species coexist in plant roots. However, almost nothing is known about the molecular interactions occurring during such coexistence. We compared in planta AMF gene transcription in single and coinoculation treatments with two genetically different isolates of Rhizophagus irregularis in symbiosis independently on three genetically different cassava genotypes. Remarkably few genes were specifically upregulated when the two fungi coexisted. Strikingly, almost all of the genes with an identifiable putative function were known to be involved in mating in other fungal species. Several genes were consistent across host plant genotypes but more upregulated genes involved in putative mating were observed in host genotype (COL2215) compared with the two other host genotypes. The AMF genes that we observed to be specifically upregulated during coexistence were either involved in the mating pheromone response, in meiosis, sexual sporulation or were homologs of MAT-locus genes known in other fungal species. We did not observe the upregulation of the expected homeodomain genes contained in a putative AMF MAT-locus, but observed upregulation of HMG-box genes similar to those known to be involved in mating in Mucoromycotina species. Finally, we demonstrated that coexistence between the two fungal genotypes in the coinoculation treatments explained the number of putative mating response genes activated in the different plant host genotypes. This study demonstrates experimentally the activation of genes involved in a putative mating response and represents an important step towards the understanding of coexistence and sexual reproduction in these important plant symbionts.
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Affiliation(s)
- Ivan D Mateus
- Department of Ecology and Evolution, University of Lausanne, Biophore building, 1015, Lausanne, Switzerland.
| | - Edward C Rojas
- Department of Ecology and Evolution, University of Lausanne, Biophore building, 1015, Lausanne, Switzerland
| | - Romain Savary
- Department of Ecology and Evolution, University of Lausanne, Biophore building, 1015, Lausanne, Switzerland
| | - Cindy Dupuis
- Department of Ecology and Evolution, University of Lausanne, Biophore building, 1015, Lausanne, Switzerland
| | - Frédéric G Masclaux
- Department of Ecology and Evolution, University of Lausanne, Biophore building, 1015, Lausanne, Switzerland
| | - Consolée Aletti
- Department of Ecology and Evolution, University of Lausanne, Biophore building, 1015, Lausanne, Switzerland
| | - Ian R Sanders
- Department of Ecology and Evolution, University of Lausanne, Biophore building, 1015, Lausanne, Switzerland.
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Naranjo‐Ortiz MA, Gabaldón T. Fungal evolution: cellular, genomic and metabolic complexity. Biol Rev Camb Philos Soc 2020; 95:1198-1232. [PMID: 32301582 PMCID: PMC7539958 DOI: 10.1111/brv.12605] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 03/31/2020] [Accepted: 04/02/2020] [Indexed: 12/13/2022]
Abstract
The question of how phenotypic and genomic complexity are inter-related and how they are shaped through evolution is a central question in biology that historically has been approached from the perspective of animals and plants. In recent years, however, fungi have emerged as a promising alternative system to address such questions. Key to their ecological success, fungi present a broad and diverse range of phenotypic traits. Fungal cells can adopt many different shapes, often within a single species, providing them with great adaptive potential. Fungal cellular organizations span from unicellular forms to complex, macroscopic multicellularity, with multiple transitions to higher or lower levels of cellular complexity occurring throughout the evolutionary history of fungi. Similarly, fungal genomes are very diverse in their architecture. Deep changes in genome organization can occur very quickly, and these phenomena are known to mediate rapid adaptations to environmental changes. Finally, the biochemical complexity of fungi is huge, particularly with regard to their secondary metabolites, chemical products that mediate many aspects of fungal biology, including ecological interactions. Herein, we explore how the interplay of these cellular, genomic and metabolic traits mediates the emergence of complex phenotypes, and how this complexity is shaped throughout the evolutionary history of Fungi.
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Affiliation(s)
- Miguel A. Naranjo‐Ortiz
- Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG)The Barcelona Institute of Science and TechnologyDr. Aiguader 88, Barcelona08003Spain
| | - Toni Gabaldón
- Bioinformatics and Genomics Programme, Centre for Genomic Regulation (CRG)The Barcelona Institute of Science and TechnologyDr. Aiguader 88, Barcelona08003Spain
- Department of Experimental Sciences, Universitat Pompeu Fabra (UPF)Dr. Aiguader 88, 08003BarcelonaSpain
- ICREAPg. Lluís Companys 23, 08010BarcelonaSpain
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8
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Škríba A, Patil RH, Hubáček P, Dobiáš R, Palyzová A, Marešová H, Pluháček T, Havlíček V. Rhizoferrin Glycosylation in Rhizopus microsporus. J Fungi (Basel) 2020; 6:jof6020089. [PMID: 32570979 PMCID: PMC7344610 DOI: 10.3390/jof6020089] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 06/14/2020] [Accepted: 06/16/2020] [Indexed: 12/13/2022] Open
Abstract
Rhizopus spp. are the most common etiological agents of mucormycosis, causing over 90% mortality in disseminated infections. The diagnosis relies on histopathology, culture, and/or polymerase chain reaction. For the first time, the glycosylation of rhizoferrin (RHF) was described in a Rhizopus microsporus clinical isolate by liquid chromatography and accurate tandem mass spectrometry. The fermentation broth lyophilizate contained 345.3 ± 13.5, 1.2 ± 0.03, and 0.03 ± 0.002 mg/g of RHF, imido-RHF, and bis-imido-RHF, respectively. Despite a considerable RHF secretion rate, we did not obtain conclusive RHF detection from a patient with disseminated mucormycosis caused by the same R. microsporus strain. We hypothesize that parallel antimycotic therapy, RHF biotransformation, and metabolism compromised the analysis. On the other hand, the full profile of posaconazole metabolites was retrieved by our in house software CycloBranch.
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Affiliation(s)
- Anton Škríba
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague, Czech Republic; (A.Š.); (R.H.P.); (A.P.); (H.M.); (T.P.)
| | - Rutuja Hiraji Patil
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague, Czech Republic; (A.Š.); (R.H.P.); (A.P.); (H.M.); (T.P.)
- Department of Analytical Chemistry, Faculty of Science, Palacký University, 771 46 Olomouc, Czech Republic
| | - Petr Hubáček
- Department of Medical Microbiology, 2nd Faculty of Medicine, Charles University and Motol University Hospital, 150 06 Prague, Czech Republic;
| | - Radim Dobiáš
- Public Health Institute in Ostrava, 702 00 Ostrava, Czech Republic;
| | - Andrea Palyzová
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague, Czech Republic; (A.Š.); (R.H.P.); (A.P.); (H.M.); (T.P.)
| | - Helena Marešová
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague, Czech Republic; (A.Š.); (R.H.P.); (A.P.); (H.M.); (T.P.)
| | - Tomáš Pluháček
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague, Czech Republic; (A.Š.); (R.H.P.); (A.P.); (H.M.); (T.P.)
- Department of Analytical Chemistry, Faculty of Science, Palacký University, 771 46 Olomouc, Czech Republic
| | - Vladimír Havlíček
- Institute of Microbiology of the Czech Academy of Sciences, Vídeňská 1083, 142 20 Prague, Czech Republic; (A.Š.); (R.H.P.); (A.P.); (H.M.); (T.P.)
- Department of Analytical Chemistry, Faculty of Science, Palacký University, 771 46 Olomouc, Czech Republic
- Correspondence:
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Abstract
Purpose of review Mucormycosis is an emerging opportunistic fungal infection whose causative agents are found within the Mucorales family. A recent increase in immunocompromised cohorts with solid organ transplants, diabetes mellitus, and other medical conditions have resulted in increased fungal infections including mucormycosis. Our current knowledge about Mucoralean fungi is in its infancy compared to other fungal pathogens, which may be due to lack of robust genetic tools for Mucorales. In this review we summarize recent advances in genetic tools to study the two most prevalent and genetically amenable Mucoralean fungi, Mucor circinelloides and Rhizopus delemar. Recent findings There have been advances made in the study of Mucorales family genetics. These findings include the construction of recyclable markers to manipulate the genome, as well as silencing vectors, and the adaptation of the CRISPR/Cas9 gene editing system. Summary We present how these genetic methods have been applied to understand basic biology, morphogenesis, pathogenesis, and host-pathogen interactions in the two Mucoralean fungi, M. circinelloides and R. delemar. With these advances in Mucorales the opportunity to further understand the pathogenesis of these organisms is opened.
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Abstract
Phylogenomic approaches have the potential to improve confidence about the inter-relationships of species in the order Mucorales within the fungal tree of life. Rhizopus species are especially important as plant and animal pathogens and bioindustrial fermenters for food and metabolite production. A dataset of 192 orthologous genes was used to construct a phylogenetic tree of 21 Rhizopus strains, classified into four species isolated from habitats of industrial, medical and environmental importance. The phylogeny indicates that the genus Rhizopus consists of three major clades, with R. microsporus as the basal species and the sister lineage to R. stolonifer and two closely related species R. arrhizus and R. delemar A comparative analysis of the mating type locus across Rhizopus reveals that its structure is flexible even between different species in the same genus, but shows similarities between Rhizopus and other mucoralean fungi. The topology of single-gene phylogenies built for two genes involved in mating is similar to the phylogenomic tree. Comparison of the total length of the genome assemblies showed that genome size varies by as much as threefold within a species and is driven by changes in transposable element copy numbers and genome duplications.
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Abstract
Although at the level of resolution of genes and molecules most information about mating in fungi is from a single lineage, the Dikarya, many fundamental discoveries about mating in fungi have been made in the earlier branches of the fungi. These are nonmonophyletic groups that were once classified into the chytrids and zygomycetes. Few species in these lineages offer the potential of genetic tractability, thereby hampering the ability to identify the genes that underlie those fundamental insights. Research performed during the past decade has now established the genes required for mating type determination and pheromone synthesis in some species in the phylum Mucoromycota, especially in the order Mucorales. These findings provide striking parallels with the evolution of mating systems in the Dikarya fungi. Other discoveries in the Mucorales provide the first examples of sex-cell type identity being driven directly by a gene that confers mating type, a trait considered more of relevance to animal sex determination but difficult to investigate in animals. Despite these discoveries, there remains much to be gleaned about mating systems from these fungi.
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12
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Calo S, Nicolás FE, Lee SC, Vila A, Cervantes M, Torres-Martinez S, Ruiz-Vazquez RM, Cardenas ME, Heitman J. A non-canonical RNA degradation pathway suppresses RNAi-dependent epimutations in the human fungal pathogen Mucor circinelloides. PLoS Genet 2017; 13:e1006686. [PMID: 28339467 PMCID: PMC5384783 DOI: 10.1371/journal.pgen.1006686] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Revised: 04/07/2017] [Accepted: 03/13/2017] [Indexed: 11/21/2022] Open
Abstract
Mucorales are a group of basal fungi that includes the casual agents of the human emerging disease mucormycosis. Recent studies revealed that these pathogens activate an RNAi-based pathway to rapidly generate drug-resistant epimutant strains when exposed to stressful compounds such as the antifungal drug FK506. To elucidate the molecular mechanism of this epimutation pathway, we performed a genetic analysis in Mucor circinelloides that revealed an inhibitory role for the non-canonical RdRP-dependent Dicer-independent silencing pathway, which is an RNAi-based mechanism involved in mRNA degradation that was recently identified. Thus, mutations that specifically block the mRNA degradation pathway, such as those in the genes r3b2 and rdrp3, enhance the production of drug resistant epimutants, similar to the phenotype previously described for mutation of the gene rdrp1. Our genetic analysis also revealed two new specific components of the epimutation pathway related to the quelling induced protein (qip) and a Sad-3-like helicase (rnhA), as mutations in these genes prevented formation of drug-resistant epimutants. Remarkably, drug-resistant epimutant production was notably increased in M. circinelloides f. circinelloides isolates from humans or other animal hosts. The host-pathogen interaction could be a stressful environment in which the phenotypic plasticity provided by the epimutant pathway might provide an advantage for these strains. These results evoke a model whereby balanced regulation of two different RNAi pathways is determined by the activation of the RNAi-dependent epimutant pathway under stress conditions, or its repression when the regular maintenance of the mRNA degradation pathway operates under non-stress conditions. Mucormycosis is a fungal infection that is attracting the attention of both clinical and research communities because of the lack of effective antifungal treatments and its often fatal prognosis. Our previous studies revealed an RNAi-mediated epimutation mechanism that operates in the casual human fungal pathogens (Mucorales species) and which might underlie the lack of efficacy of some antifungal treatments. This epimutation mechanism represses the expression of antifungal drug target genes and thereby generates antifungal drug resistant strains. Here, we studied the regulation and identified new components of the epimutation pathway. We found that a newly identified mRNA degradation pathway, named the non-canonical RdRP-dependent Dicer-independent silencing pathway, exerts an inhibitory effect on the RNAi-mediated epimutation mechanism and operates during growth under non-stressful conditions. Interestingly, the RNAi-based epimutation mechanism is more active in M. circinelloides f. circinelloides isolates from human and other animal sources, suggesting that this mechanism may influence host-pathogen interactions. These results further our understanding of the mechanisms deployed by fungal pathogens to survive and adapt under stressful environmental conditions that may include the host niche.
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Affiliation(s)
- Silvia Calo
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Francisco E. Nicolás
- Department of Genetics and Microbiology, Faculty of Biology, University of Murcia, Murcia, Spain
| | - Soo Chan Lee
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Ana Vila
- Department of Genetics and Microbiology, Faculty of Biology, University of Murcia, Murcia, Spain
| | - Maria Cervantes
- Department of Genetics and Microbiology, Faculty of Biology, University of Murcia, Murcia, Spain
| | - Santiago Torres-Martinez
- Department of Genetics and Microbiology, Faculty of Biology, University of Murcia, Murcia, Spain
| | - Rosa M. Ruiz-Vazquez
- Department of Genetics and Microbiology, Faculty of Biology, University of Murcia, Murcia, Spain
| | - Maria E. Cardenas
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Joseph Heitman
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, North Carolina, United States of America
- * E-mail:
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The inhibition of mating in Phycomyces blakesleeanus by light is dependent on the MadA-MadB complex that acts in a sex-specific manner. Fungal Genet Biol 2017; 101:20-30. [PMID: 28214601 DOI: 10.1016/j.fgb.2017.02.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2016] [Revised: 01/23/2017] [Accepted: 02/13/2017] [Indexed: 12/15/2022]
Abstract
Light is an environmental signal that influences reproduction in the Mucoromycotina fungi, as it does in many other species of fungi. Mating in Phycomyces blakesleeanus is inhibited by light, but the molecular mechanisms for this inhibition are uncharacterized. In this analysis, the role of the light-sensing MadA-MadB complex in mating was tested. The MadA-MadB complex is homologous to the Neurospora crassa White Collar complex. Three genes required for cell type determination in the sex locus or pheromone biosynthesis are transcriptionally-regulated by light and are controlled by MadA and MadB. This regulation acts through the plus partner, indicating that the inhibitory effect of light on mating is executed through only one of the two sexes. These results are an example whereby the mating types of fungi have acquired sex-specific properties beyond their role in conferring cell-type identity, and provide insight into how sex-determining chromosomal regions can expand the traits they control.
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Morin-Sardin S, Nodet P, Coton E, Jany JL. Mucor: A Janus-faced fungal genus with human health impact and industrial applications. FUNGAL BIOL REV 2017. [DOI: 10.1016/j.fbr.2016.11.002] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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