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Cohen AB, Cai G, Price DC, Molnar TJ, Zhang N, Hillman BI. The massive 340 megabase genome of Anisogramma anomala, a biotrophic ascomycete that causes eastern filbert blight of hazelnut. BMC Genomics 2024; 25:347. [PMID: 38580927 PMCID: PMC10998396 DOI: 10.1186/s12864-024-10198-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 03/07/2024] [Indexed: 04/07/2024] Open
Abstract
BACKGROUND The ascomycete fungus Anisogramma anomala causes Eastern Filbert Blight (EFB) on hazelnut (Corylus spp.) trees. It is a minor disease on its native host, the American hazelnut (C. americana), but is highly destructive on the commercially important European hazelnut (C. avellana). In North America, EFB has historically limited commercial production of hazelnut to west of the Rocky Mountains. A. anomala is an obligately biotrophic fungus that has not been grown in continuous culture, rendering its study challenging. There is a 15-month latency before symptoms appear on infected hazelnut trees, and only a sexual reproductive stage has been observed. Here we report the sequencing, annotation, and characterization of its genome. RESULTS The genome of A. anomala was assembled into 108 scaffolds totaling 342,498,352 nt with a GC content of 34.46%. Scaffold N50 was 33.3 Mb and L50 was 5. Nineteen scaffolds with lengths over 1 Mb constituted 99% of the assembly. Telomere sequences were identified on both ends of two scaffolds and on one end of another 10 scaffolds. Flow cytometry estimated the genome size of A. anomala at 370 Mb. The genome exhibits two-speed evolution, with 93% of the assembly as AT-rich regions (32.9% GC) and the other 7% as GC-rich (57.1% GC). The AT-rich regions consist predominantly of repeats with low gene content, while 90% of predicted protein coding genes were identified in GC-rich regions. Copia-like retrotransposons accounted for more than half of the genome. Evidence of repeat-induced point mutation (RIP) was identified throughout the AT-rich regions, and two copies of the rid gene and one of dim-2, the key genes in the RIP mutation pathway, were identified in the genome. Consistent with its homothallic sexual reproduction cycle, both MAT1-1 and MAT1-2 idiomorphs were found. We identified a large suite of genes likely involved in pathogenicity, including 614 carbohydrate active enzymes, 762 secreted proteins and 165 effectors. CONCLUSIONS This study reveals the genomic structure, composition, and putative gene function of the important pathogen A. anomala. It provides insight into the molecular basis of the pathogen's life cycle and a solid foundation for studying EFB.
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Affiliation(s)
- Alanna B Cohen
- Department of Plant Biology, Rutgers The State University of New Jersey, New Brunswick, NJ, 08901, USA
- Graduate Program in Microbial Biology, Rutgers The State University of New Jersey, New Brunswick, NJ, 08901, USA
| | - Guohong Cai
- Crop Production and Pest Control Research Unit, USDA-ARS, West Lafayette, IN, 47907, USA.
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, 47907, USA.
| | - Dana C Price
- Department of Entomology, Rutgers The State University of New Jersey, New Brunswick, NJ, 08901, USA
- Center for Vector Biology, Rutgers The State University of New Jersey, New Brunswick, NJ, 08901, USA
| | - Thomas J Molnar
- Department of Plant Biology, Rutgers The State University of New Jersey, New Brunswick, NJ, 08901, USA
| | - Ning Zhang
- Department of Plant Biology, Rutgers The State University of New Jersey, New Brunswick, NJ, 08901, USA
- Graduate Program in Microbial Biology, Rutgers The State University of New Jersey, New Brunswick, NJ, 08901, USA
- Department of Biochemistry and Microbiology, Rutgers The State University of New Jersey, New Brunswick, NJ, 08901, USA
| | - Bradley I Hillman
- Department of Plant Biology, Rutgers The State University of New Jersey, New Brunswick, NJ, 08901, USA.
- Graduate Program in Microbial Biology, Rutgers The State University of New Jersey, New Brunswick, NJ, 08901, USA.
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2
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Ma C, Liu J, Tang J, Sun Y, Jiang X, Zhang T, Feng Y, Liu Q, Wang L. Current genetic strategies to investigate gene functions in Trichoderma reesei. Microb Cell Fact 2023; 22:97. [PMID: 37161391 PMCID: PMC10170752 DOI: 10.1186/s12934-023-02104-3] [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: 11/20/2022] [Accepted: 04/21/2023] [Indexed: 05/11/2023] Open
Abstract
The filamentous fungus Trichoderma reesei (teleomorph Hypocrea jecorina, Ascomycota) is a well-known lignocellulolytic enzymes-producing strain in industry. To increase the fermentation titer of lignocellulolytic enzymes, random mutagenesis and rational genetic engineering in T. reesei were carried out since it was initially found in the Solomon Islands during the Second World War. Especially the continuous exploration of the underlying regulatory network during (hemi)cellulase gene expression in the post-genome era provided various strategies to develop an efficient fungal cell factory for these enzymes' production. Meanwhile, T. reesei emerges competitiveness potential as a filamentous fungal chassis to produce proteins from other species (e.g., human albumin and interferon α-2b, SARS-CoV-2 N antigen) in virtue of the excellent expression and secretion system acquired during the studies about (hemi)cellulase production. However, all the achievements in high yield of (hemi)cellulases are impossible to finish without high-efficiency genetic strategies to analyze the proper functions of those genes involved in (hemi)cellulase gene expression or secretion. Here, we in detail summarize the current strategies employed to investigate gene functions in T. reesei. These strategies are supposed to be beneficial for extending the potential of T. reesei in prospective strain engineering.
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Affiliation(s)
- Chixiang Ma
- China Medical University-The Queen's University of Belfast Joint College, Shenyang, Liaoning, 110122, China
| | - Jialong Liu
- College of Basic Medical Sciences, Shanxi Medical University, Taiyuan, 030001, Shanxi, China
| | - Jiaxin Tang
- College of Basic Medical Sciences, Shanxi Medical University, Taiyuan, 030001, Shanxi, China
| | - Yuanlu Sun
- China Medical University-The Queen's University of Belfast Joint College, Shenyang, Liaoning, 110122, China
| | - Xiaojie Jiang
- China Medical University-The Queen's University of Belfast Joint College, Shenyang, Liaoning, 110122, China
| | - Tongtong Zhang
- China Medical University-The Queen's University of Belfast Joint College, Shenyang, Liaoning, 110122, China
| | - Yan Feng
- College of Life Sciences, Shanxi Agricultural University, Jinzhong, 030801, Shanxi, China
| | - Qinghua Liu
- College of Basic Medical Sciences, Shanxi Medical University, Taiyuan, 030001, Shanxi, China
| | - Lei Wang
- College of Basic Medical Sciences, Shanxi Medical University, Taiyuan, 030001, Shanxi, China.
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Hybrid de novo genome assembly and comparative genomics of three different isolates of Gnomoniopsis castaneae. Sci Rep 2023; 13:3356. [PMID: 36849528 PMCID: PMC9971261 DOI: 10.1038/s41598-023-30496-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Accepted: 02/24/2023] [Indexed: 03/01/2023] Open
Abstract
The first genome assemblies of Gnomoniopsis castaneae (syn. G. smithogilvyi), the causal agent of chestnut brown rot of kernels, shoot blight and cankers, are provided here. Specifically, the complete genome of the Italian ex-type MUT401 isolate was compared to the draft genome of a second Italian isolate (GN01) and to the ICMP 14040 isolate from New Zealand. The three genome sequences were obtained through a hybrid assembly using both short Illumina reads and long Nanopore reads, their coding sequences were annotated and compared with each other and with other Diaporthales. The information offered by the genome assembly of the three isolates represents the base of data for further application related to -omics strategies of the fungus and to develop markers for population studies at a local and global scale.
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4
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Zhang C, Tian Y, Song S, Zhang L, Dang Y, He Q. H3K56 deacetylation and H2A.Z deposition are required for aberrant heterochromatin spreading. Nucleic Acids Res 2022; 50:3852-3866. [PMID: 35333354 PMCID: PMC9023284 DOI: 10.1093/nar/gkac196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Revised: 03/10/2022] [Accepted: 03/15/2022] [Indexed: 11/21/2022] Open
Abstract
Crucial mechanisms are required to restrict self-propagating heterochromatin spreading within defined boundaries and prevent euchromatic gene silencing. In the filamentous fungus Neurospora crassa, the JmjC domain protein DNA METHYLATION MODULATOR-1 (DMM-1) prevents aberrant spreading of heterochromatin, but the molecular details remain unknown. Here, we revealed that DMM-1 is highly enriched in a well-defined 5-kb heterochromatin domain upstream of the cat-3 gene, hereby called 5H-cat-3 domain, to constrain aberrant heterochromatin spreading. Interestingly, aberrant spreading of the 5H-cat-3 domain observed in the dmm-1KO strain is accompanied by robust deposition of histone variant H2A.Z, and deletion of H2A.Z abolishes aberrant spreading of the 5H-cat-3 domain into adjacent euchromatin. Furthermore, lysine 56 of histone H3 is deacetylated at the expanded heterochromatin regions, and mimicking H3K56 acetylation with an H3K56Q mutation effectively blocks H2A.Z-mediated aberrant spreading of the 5H-cat-3 domain. Importantly, genome-wide analyses demonstrated the general roles of H3K56 deacetylation and H2A.Z deposition in aberrant spreading of heterochromatin. Together, our results illustrate a previously unappreciated regulatory process that mediates aberrant heterochromatin spreading.
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Affiliation(s)
- Chengcheng Zhang
- State Key Laboratory of Agrobiotechnology and MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Yuan Tian
- State Key Laboratory of Agrobiotechnology and MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
| | - Shuang Song
- State Key Laboratory for Conservation and Utilization of Bio-Resources and Center for Life Science, School of Life Sciences, Yunnan University, Kunming, Yunnan 650091, China
| | - Lu Zhang
- State Key Laboratory for Conservation and Utilization of Bio-Resources and Center for Life Science, School of Life Sciences, Yunnan University, Kunming, Yunnan 650091, China
| | - Yunkun Dang
- State Key Laboratory for Conservation and Utilization of Bio-Resources and Center for Life Science, School of Life Sciences, Yunnan University, Kunming, Yunnan 650091, China
| | - Qun He
- State Key Laboratory of Agrobiotechnology and MOA Key Laboratory of Soil Microbiology, College of Biological Sciences, China Agricultural University, Beijing 100193, China
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Treindl AD, Stapley J, Winter DJ, Cox MP, Leuchtmann A. Chromosome-level genomes provide insights into genome evolution, organization and size in Epichloe fungi. Genomics 2021; 113:4267-4275. [PMID: 34774981 DOI: 10.1016/j.ygeno.2021.11.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Revised: 10/21/2021] [Accepted: 11/08/2021] [Indexed: 01/10/2023]
Abstract
Epichloe fungi are endophytes of cool season grasses, both wild species and commercial cultivars, where they may exhibit mutualistic or pathogenic lifestyles. The Epichloe-grass symbiosis is of great interest to agricultural research for the fungal bioprotective properties conferred to host grasses but also serves as an ideal system to study the evolution of fungal plant-pathogens in natural environments. Here, we assembled and annotated gapless chromosome-level genomes of two pathogenic Epichloe sibling species. Both genomes have a bipartite genome organization, with blocks of highly syntenic gene-rich regions separated by blocks of AT-rich DNA. The AT-rich regions show an extensive signature of RIP (repeat-induced point mutation) and the expansion of this compartment accounts for the large difference in genome size between the two species. This study reveals how the rapid evolution of repeat structure can drive divergence between closely related taxa and highlights the evolutionary role of dynamic compartments in fungal genomes.
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Affiliation(s)
- Artemis D Treindl
- Plant Ecological Genetics Group, Institute of Integrative Biology, ETH Zurich, 8092 Zurich, Switzerland.
| | - Jessica Stapley
- Plant Ecological Genetics Group, Institute of Integrative Biology, ETH Zurich, 8092 Zurich, Switzerland
| | - David J Winter
- Statistics and Bioinformatics Group, School of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
| | - Murray P Cox
- Statistics and Bioinformatics Group, School of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
| | - Adrian Leuchtmann
- Plant Ecological Genetics Group, Institute of Integrative Biology, ETH Zurich, 8092 Zurich, Switzerland
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6
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Porquier A, Tisserant C, Salinas F, Glassl C, Wange L, Enard W, Hauser A, Hahn M, Weiberg A. Retrotransposons as pathogenicity factors of the plant pathogenic fungus Botrytis cinerea. Genome Biol 2021; 22:225. [PMID: 34399815 PMCID: PMC8365987 DOI: 10.1186/s13059-021-02446-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2021] [Accepted: 07/26/2021] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Retrotransposons are genetic elements inducing mutations in all domains of life. Despite their detrimental effect, retrotransposons can become temporarily active during epigenetic reprogramming and cellular stress response, which may accelerate host genome evolution. In fungal pathogens, a positive role has been attributed to retrotransposons when shaping genome architecture and expression of genes encoding pathogenicity factors; thus, retrotransposons are known to influence pathogenicity. RESULTS We uncover a hitherto unknown role of fungal retrotransposons as being pathogenicity factors, themselves. The aggressive fungal plant pathogen, Botrytis cinerea, is known to deliver some long-terminal repeat (LTR) deriving regulatory trans-species small RNAs (BcsRNAs) into plant cells to suppress host gene expression for infection. We find that naturally occurring, less aggressive B. cinerea strains possess considerably lower copy numbers of LTR retrotransposons and had lost retrotransposon BcsRNA production. Using a transgenic proof-of-concept approach, we reconstitute retrotransposon expression in a BcsRNA-lacking B. cinerea strain, which results in enhanced aggressiveness in a retrotransposon and BcsRNA expression-dependent manner. Moreover, retrotransposon expression in B. cinerea leads to suppression of plant defence-related genes during infection. CONCLUSIONS We propose that retrotransposons are pathogenicity factors that manipulate host plant gene expression by encoding trans-species BcsRNAs. Taken together, the novelty that retrotransposons are pathogenicity factors will have a broad impact on studies of host-microbe interactions and pathology.
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Affiliation(s)
| | | | | | - Carla Glassl
- Faculty of Biology, Genetics, LMU Munich, Martinsried, Germany
| | - Lucas Wange
- Faculty of Biology, Anthropology & Human Genomics, LMU Munich, Martinsried, Germany
| | - Wolfgang Enard
- Faculty of Biology, Anthropology & Human Genomics, LMU Munich, Martinsried, Germany
| | - Andreas Hauser
- Gene Center, Laboratory for Functional Genome Analysis, LMU Munich, Martinsried, Germany
| | - Matthias Hahn
- Department of Biology, University of Kaiserslautern, Kaiserslautern, Germany
| | - Arne Weiberg
- Faculty of Biology, Genetics, LMU Munich, Martinsried, Germany.
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7
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Elfstrand M, Chen J, Cleary M, Halecker S, Ihrmark K, Karlsson M, Davydenko K, Stenlid J, Stadler M, Durling MB. Comparative analyses of the Hymenoscyphus fraxineus and Hymenoscyphus albidus genomes reveals potentially adaptive differences in secondary metabolite and transposable element repertoires. BMC Genomics 2021; 22:503. [PMID: 34217229 PMCID: PMC8254937 DOI: 10.1186/s12864-021-07837-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Accepted: 06/24/2021] [Indexed: 11/29/2022] Open
Abstract
Background The dieback epidemic decimating common ash (Fraxinus excelsior) in Europe is caused by the invasive fungus Hymenoscyphus fraxineus. In this study we analyzed the genomes of H. fraxineus and H. albidus, its native but, now essentially displaced, non-pathogenic sister species, and compared them with several other members of Helotiales. The focus of the analyses was to identify signals in the genome that may explain the rapid establishment of H. fraxineus and displacement of H. albidus. Results The genomes of H. fraxineus and H. albidus showed a high level of synteny and identity. The assembly of H. fraxineus is 13 Mb longer than that of H. albidus’, most of this difference can be attributed to higher dispersed repeat content (i.e. transposable elements [TEs]) in H. fraxineus. In general, TE families in H. fraxineus showed more signals of repeat-induced point mutations (RIP) than in H. albidus, especially in Long-terminal repeat (LTR)/Copia and LTR/Gypsy elements. Comparing gene family expansions and 1:1 orthologs, relatively few genes show signs of positive selection between species. However, several of those did appeared to be associated with secondary metabolite genes families, including gene families containing two of the genes in the H. fraxineus-specific, hymenosetin biosynthetic gene cluster (BGC). Conclusion The genomes of H. fraxineus and H. albidus show a high degree of synteny, and are rich in both TEs and BGCs, but the genomic signatures also indicated that H. albidus may be less well equipped to adapt and maintain its ecological niche in a rapidly changing environment. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-07837-2.
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Affiliation(s)
- Malin Elfstrand
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Almas Allé 5, Box 7026, SE-750 07, Uppsala, Sweden.
| | - Jun Chen
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Almas Allé 5, Box 7026, SE-750 07, Uppsala, Sweden.,Systematic & Evolutionary Botany and Biodiversity group, MOE Laboratory of Biosystem Homeostasis and Protection, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang, China
| | - Michelle Cleary
- Southern Swedish Forest Research Centre, Swedish University of Agricultural Sciences, Sundsvägen 3, Box 49, SE-230 53, Alnarp, Sweden
| | - Sandra Halecker
- Dept. Microbial Drugs, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, D-38124, Braunschweig, Germany
| | - Katarina Ihrmark
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Almas Allé 5, Box 7026, SE-750 07, Uppsala, Sweden
| | - Magnus Karlsson
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Almas Allé 5, Box 7026, SE-750 07, Uppsala, Sweden
| | - Kateryna Davydenko
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Almas Allé 5, Box 7026, SE-750 07, Uppsala, Sweden.,Ukrainian research Institute of Forestry and Forest Melioration, 62458, Kharkov, Ukraine
| | - Jan Stenlid
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Almas Allé 5, Box 7026, SE-750 07, Uppsala, Sweden
| | - Marc Stadler
- Dept. Microbial Drugs, Helmholtz Centre for Infection Research, Inhoffenstrasse 7, D-38124, Braunschweig, Germany
| | - Mikael Brandström Durling
- Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Almas Allé 5, Box 7026, SE-750 07, Uppsala, Sweden
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Tobias PA, Schwessinger B, Deng CH, Wu C, Dong C, Sperschneider J, Jones A, Lou Z, Zhang P, Sandhu K, Smith GR, Tibbits J, Chagné D, Park RF. Austropuccinia psidii, causing myrtle rust, has a gigabase-sized genome shaped by transposable elements. G3 (BETHESDA, MD.) 2021; 11:jkaa015. [PMID: 33793741 PMCID: PMC8063080 DOI: 10.1093/g3journal/jkaa015] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Accepted: 10/26/2020] [Indexed: 02/06/2023]
Abstract
Austropuccinia psidii, originating in South America, is a globally invasive fungal plant pathogen that causes rust disease on Myrtaceae. Several biotypes are recognized, with the most widely distributed pandemic biotype spreading throughout the Asia-Pacific and Oceania regions over the last decade. Austropuccinia psidii has a broad host range with more than 480 myrtaceous species. Since first detected in Australia in 2010, the pathogen has caused the near extinction of at least three species and negatively affected commercial production of several Myrtaceae. To enable molecular and evolutionary studies into A. psidii pathogenicity, we assembled a highly contiguous genome for the pandemic biotype. With an estimated haploid genome size of just over 1 Gb (gigabases), it is the largest assembled fungal genome to date. The genome has undergone massive expansion via distinct transposable element (TE) bursts. Over 90% of the genome is covered by TEs predominantly belonging to the Gypsy superfamily. These TE bursts have likely been followed by deamination events of methylated cytosines to silence the repetitive elements. This in turn led to the depletion of CpG sites in TEs and a very low overall GC content of 33.8%. Compared to other Pucciniales, the intergenic distances are increased by an order of magnitude indicating a general insertion of TEs between genes. Overall, we show how TEs shaped the genome evolution of A. psidii and provide a greatly needed resource for strategic approaches to combat disease spread.
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Affiliation(s)
- Peri A Tobias
- School of Life and Environmental Sciences, University of Sydney, Camperdown, NSW 2006, Australia
- Plant & Food Research Australia, SA 5064, Australia
| | - Benjamin Schwessinger
- Australia Research School of Biology, The Australian National University, Acton, ACT 2601, Australia
| | - Cecilia H Deng
- The New Zealand Institute for Plant and Food Research Limited, Auckland 1142, New Zealand
| | - Chen Wu
- The New Zealand Institute for Plant and Food Research Limited, Auckland 1142, New Zealand
| | - Chongmei Dong
- Plant Breeding Institute, University of Sydney, Narellan, NSW 2567, Australia
| | - Jana Sperschneider
- Biological Data Science Institute, The Australian National University, Canberra, ACT, 2600, Australia
| | - Ashley Jones
- Australia Research School of Biology, The Australian National University, Acton, ACT 2601, Australia
| | - Zhenyan Lou
- Australia Research School of Biology, The Australian National University, Acton, ACT 2601, Australia
| | - Peng Zhang
- Plant Breeding Institute, University of Sydney, Narellan, NSW 2567, Australia
| | - Karanjeet Sandhu
- Plant Breeding Institute, University of Sydney, Narellan, NSW 2567, Australia
| | - Grant R Smith
- The New Zealand Institute for Plant and Food Research Limited, Christchurch 8140, New Zealand
| | - Josquin Tibbits
- Agriculture Victoria Department of Jobs, Precincts and Regions, Bundoora, VIC 3083, Australia
| | - David Chagné
- The New Zealand Institute for Plant & Food Research, Palmerston North 4442, New Zealand
| | - Robert F Park
- Plant Breeding Institute, University of Sydney, Narellan, NSW 2567, Australia
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9
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van Wyk S, Wingfield BD, De Vos L, van der Merwe NA, Steenkamp ET. Genome-Wide Analyses of Repeat-Induced Point Mutations in the Ascomycota. Front Microbiol 2021; 11:622368. [PMID: 33597932 PMCID: PMC7882544 DOI: 10.3389/fmicb.2020.622368] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Accepted: 12/29/2020] [Indexed: 11/17/2022] Open
Abstract
The Repeat-Induced Point (RIP) mutation pathway is a fungus-specific genome defense mechanism that mitigates the deleterious consequences of repeated genomic regions and transposable elements (TEs). RIP mutates targeted sequences by introducing cytosine to thymine transitions. We investigated the genome-wide occurrence and extent of RIP with a sliding-window approach. Using genome-wide RIP data and two sets of control groups, the association between RIP, TEs, and GC content were contrasted in organisms capable and incapable of RIP. Based on these data, we then set out to determine the extent and occurrence of RIP in 58 representatives of the Ascomycota. The findings were summarized by placing each of the fungi investigated in one of six categories based on the extent of genome-wide RIP. In silico RIP analyses, using a sliding-window approach with stringent RIP parameters, implemented simultaneously within the same genetic context, on high quality genome assemblies, yielded superior results in determining the genome-wide RIP among the Ascomycota. Most Ascomycota had RIP and these mutations were particularly widespread among classes of the Pezizomycotina, including the early diverging Orbiliomycetes and the Pezizomycetes. The most extreme cases of RIP were limited to representatives of the Dothideomycetes and Sordariomycetes. By contrast, the genomes of the Taphrinomycotina and Saccharomycotina contained no detectable evidence of RIP. Also, recent losses in RIP combined with controlled TE proliferation in the Pezizomycotina subphyla may promote substantial genome enlargement as well as the formation of sub-genomic compartments. These findings have broadened our understanding of the taxonomic range and extent of RIP in Ascomycota and how this pathway affects the genomes of fungi harboring it.
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Affiliation(s)
| | | | | | | | - Emma T. Steenkamp
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, South Africa
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10
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Wang L, Sun Y, Sun X, Yu L, Xue L, He Z, Huang J, Tian D, Hurst LD, Yang S. Repeat-induced point mutation in Neurospora crassa causes the highest known mutation rate and mutational burden of any cellular life. Genome Biol 2020; 21:142. [PMID: 32546205 PMCID: PMC7296669 DOI: 10.1186/s13059-020-02060-w] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Accepted: 05/27/2020] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Repeat-induced point (RIP) mutation in Neurospora crassa degrades transposable elements by targeting repeats with C→T mutations. Whether RIP affects core genomic sequence in important ways is unknown. RESULTS By parent-offspring whole genome sequencing, we estimate a mutation rate (3.38 × 10-6 per bp per generation) that is two orders of magnitude higher than reported for any non-viral organism, with 93-98% of mutations being RIP-associated. RIP mutations are, however, relatively rare in coding sequence, in part because RIP preferentially attacks GC-poor long duplicates that interact in three dimensional space, while coding sequence duplicates are rare, GC-rich, short, and tend not to interact. Despite this, with over 5 coding sequence mutations per genome per generation, the mutational burden is an order of magnitude higher than the previously highest observed. Unexpectedly, the majority of these coding sequence mutations appear not to be the direct product of RIP being mostly in non-duplicate sequence and predominantly not C→T mutations. Nonetheless, RIP-deficient strains have over an order of magnitude fewer coding sequence mutations outside of duplicated domains than RIP-proficient strains. CONCLUSIONS Neurospora crassa has the highest mutation rate and mutational burden of any non-viral life. While the high rate is largely due to the action of RIP, the mutational burden appears to be RIP-associated but not directly caused by RIP.
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Affiliation(s)
- Long Wang
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, 210023, China
| | - Yingying Sun
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, 210023, China
| | - Xiaoguang Sun
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, 210023, China
| | - Luyao Yu
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, 210023, China
| | - Lan Xue
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, 210023, China
| | - Zhen He
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, 210023, China
| | - Ju Huang
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, 210023, China
| | - Dacheng Tian
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, 210023, China
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, China
| | - Laurence D Hurst
- Department of Biology and Biochemistry, The Milner Centre for Evolution, University of Bath, Bath, UK.
| | - Sihai Yang
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing, 210023, China.
- State Key Laboratory for Crop Genetics and Germplasm Enhancement, Nanjing Agricultural University, Nanjing, 210095, China.
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van Wyk S, Wingfield BD, De Vos L, van der Merwe NA, Santana QC, Steenkamp ET. Repeat-Induced Point Mutations Drive Divergence between Fusarium circinatum and Its Close Relatives. Pathogens 2019; 8:pathogens8040298. [PMID: 31847413 PMCID: PMC6963459 DOI: 10.3390/pathogens8040298] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Revised: 12/06/2019] [Accepted: 12/09/2019] [Indexed: 01/01/2023] Open
Abstract
The Repeat-Induced Point (RIP) mutation pathway is a fungal-specific genome defense mechanism that counteracts the deleterious effects of transposable elements. This pathway permanently mutates its target sequences by introducing cytosine to thymine transitions. We investigated the genome-wide occurrence of RIP in the pitch canker pathogen, Fusarium circinatum, and its close relatives in the Fusarium fujikuroi species complex (FFSC). Our results showed that the examined fungi all exhibited hallmarks of RIP, but that they differed in terms of the extent to which their genomes were affected by this pathway. RIP mutations constituted a large proportion of all the FFSC genomes, including both core and dispensable chromosomes, although the latter were generally more extensively affected by RIP. Large RIP-affected genomic regions were also much more gene sparse than the rest of the genome. Our data further showed that RIP-directed sequence diversification increased the variability between homologous regions of related species, and that RIP-affected regions can interfere with homologous recombination during meiosis, thereby contributing to post-mating segregation distortion. Taken together, these findings suggest that RIP can drive the independent divergence of chromosomes, alter chromosome architecture, and contribute to the divergence among F. circinatum and other members of this economically important group of fungi.
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12
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The Parauncinula polyspora Draft Genome Provides Insights into Patterns of Gene Erosion and Genome Expansion in Powdery Mildew Fungi. mBio 2019; 10:mBio.01692-19. [PMID: 31551331 PMCID: PMC6759760 DOI: 10.1128/mbio.01692-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Powdery mildew fungi are widespread and agronomically relevant phytopathogens causing major yield losses. Their genomes have disproportionately large numbers of mobile genetic elements, and they have experienced a significant loss of highly conserved fungal genes. In order to learn more about the evolutionary history of this fungal group, we explored the genome of an Asian oak tree pathogen, Parauncinula polyspora, a species that diverged early during evolution from the remaining powdery mildew fungi. We found that the P. polyspora draft genome is comparatively compact, has a low number of protein-coding genes, and, despite the absence of a dedicated genome defense system, lacks the massive proliferation of repetitive sequences. Based on these findings, we infer an evolutionary trajectory that shaped the genomes of powdery mildew fungi. Due to their comparatively small genome size and short generation time, fungi are exquisite model systems to study eukaryotic genome evolution. Powdery mildew fungi present an exceptional case because of their strict host dependency (termed obligate biotrophy) and the atypical size of their genomes (>100 Mb). This size expansion is largely due to the pervasiveness of transposable elements on 70% of the genome and is associated with the loss of multiple conserved ascomycete genes required for a free-living lifestyle. To date, little is known about the mechanisms that drove these changes, and information on ancestral powdery mildew genomes is lacking. We report genome analysis of the early-diverged and exclusively sexually reproducing powdery mildew fungus Parauncinula polyspora, which we performed on the basis of a natural leaf epiphytic metapopulation sample. In contrast to other sequenced species of this taxonomic group, the assembled P. polyspora draft genome is surprisingly small (<30 Mb), has a higher content of conserved ascomycete genes, and is sparsely equipped with transposons (<10%), despite the conserved absence of a common defense mechanism involved in constraining repetitive elements. We speculate that transposable element spread might have been limited by this pathogen’s unique reproduction strategy and host features and further hypothesize that the loss of conserved ascomycete genes may promote the evolutionary isolation and host niche specialization of powdery mildew fungi. Limitations associated with this evolutionary trajectory might have been in part counteracted by the evolution of plastic, transposon-rich genomes and/or the expansion of gene families encoding secreted virulence proteins.
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13
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van Wyk S, Harrison CH, Wingfield BD, De Vos L, van der Merwe NA, Steenkamp ET. The RIPper, a web-based tool for genome-wide quantification of Repeat-Induced Point (RIP) mutations. PeerJ 2019; 7:e7447. [PMID: 31523495 PMCID: PMC6714961 DOI: 10.7717/peerj.7447] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 07/09/2019] [Indexed: 12/24/2022] Open
Abstract
Background The RIPper (http://theripper.hawk.rocks) is a set of web-based tools designed for analyses of Repeat-Induced Point (RIP) mutations in the genome sequences of Ascomycota. The RIP pathway is a fungal genome defense mechanism that is aimed at identifying repeated and duplicated motifs, into which it then introduces cytosine to thymine transition mutations. RIP thus serves to deactivate and counteract the deleterious consequences of selfish or mobile DNA elements in fungal genomes. The occurrence, genetic context and frequency of RIP mutations are widely used to assess the activity of this pathway in genomic regions of interest. Here, we present a bioinformatics tool that is specifically fashioned to automate the investigation of changes in RIP product and substrate nucleotide frequencies in fungal genomes. Results We demonstrated the ability of The RIPper to detect the occurrence and extent of RIP mutations in known RIP affected sequences. Specifically, a sliding window approach was used to perform genome-wide RIP analysis on the genome assembly of Neurospora crassa. Additionally, fine-scale analysis with The RIPper showed that gene regions and transposable element sequences, previously determined to be affected by RIP, were indeed characterized by high frequencies of RIP mutations. Data generated using this software further showed that large proportions of the N. crassa genome constitutes RIP mutations with extensively affected regions displaying reduced GC content. The RIPper was further useful for investigating and visualizing changes in RIP mutations across the length of sequences of interest, allowing for fine-scale analyses. Conclusion This software identified RIP targeted genomic regions and provided RIP statistics for an entire genome assembly, including the genomic proportion affected by RIP. Here, we present The RIPper as an efficient tool for genome-wide RIP analyses.
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Affiliation(s)
- Stephanie van Wyk
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, Gauteng, South Africa
| | - Christopher H Harrison
- Department of product and software development, Amplo PTY, Pretoria, Gauteng, South Africa
| | - Brenda D Wingfield
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, Gauteng, South Africa
| | - Lieschen De Vos
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, Gauteng, South Africa
| | - Nicolaas A van der Merwe
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, Gauteng, South Africa
| | - Emma T Steenkamp
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria, Gauteng, South Africa
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14
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Bewick AJ, Hofmeister BT, Powers RA, Mondo SJ, Grigoriev IV, James TY, Stajich JE, Schmitz RJ. Diversity of cytosine methylation across the fungal tree of life. Nat Ecol Evol 2019; 3:479-490. [PMID: 30778188 PMCID: PMC6533610 DOI: 10.1038/s41559-019-0810-9] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2018] [Accepted: 01/13/2019] [Indexed: 12/22/2022]
Abstract
The generation of thousands of fungal genomes is leading to a better understanding of genes and genomic organization within the kingdom. However, the epigenome, which includes DNA and chromatin modifications, remains poorly investigated in fungi. Large comparative studies in animals and plants have deepened our understanding of epigenomic variation, particularly of the modified base 5-methylcytosine (5mC), but taxonomic sampling of disparate groups is needed to develop unifying explanations for 5mC variation. Here we utilize the largest phylogenetic resolution of 5mC methyltransferases (5mC MTases) and genome evolution to better understand levels and patterns of 5mC across fungi. We show that extant 5mC MTase genotypes are descendent from ancestral maintenance and de novo genotypes, whereas the 5mC MTases DIM-2 and RID are more recently derived, and that 5mC levels are correlated with 5mC MTase genotype and transposon content. Our survey also revealed that fungi lack canonical gene body methylation, which distinguishes fungal epigenomes from certain insect and plant species. However, some fungal species possess independently derived clusters of contiguous 5mC encompassing many genes. In some cases, DNA repair pathways and the N6-methyladenine (6mA) DNA modification negatively coevolved with 5mC pathways, which additionally contributed to interspecific epigenomic variation across fungi.
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Affiliation(s)
- Adam J Bewick
- Department of Genetics, University of Georgia, Athens, GA, USA.
| | | | - Rob A Powers
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Stephen J Mondo
- US Department of Energy Joint Genome Institute, Walnut Creek, Berkeley, CA, USA
| | - Igor V Grigoriev
- US Department of Energy Joint Genome Institute, Walnut Creek, Berkeley, CA, USA.,Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Timothy Y James
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI, USA
| | - Jason E Stajich
- Department of Microbiology and Plant Pathology, University of California, Riverside, Riverside, CA, USA
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15
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Winter DJ, Ganley ARD, Young CA, Liachko I, Schardl CL, Dupont PY, Berry D, Ram A, Scott B, Cox MP. Repeat elements organise 3D genome structure and mediate transcription in the filamentous fungus Epichloë festucae. PLoS Genet 2018; 14:e1007467. [PMID: 30356280 PMCID: PMC6218096 DOI: 10.1371/journal.pgen.1007467] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 11/05/2018] [Accepted: 08/27/2018] [Indexed: 11/18/2022] Open
Abstract
Structural features of genomes, including the three-dimensional arrangement of DNA in the nucleus, are increasingly seen as key contributors to the regulation of gene expression. However, studies on how genome structure and nuclear organisation influence transcription have so far been limited to a handful of model species. This narrow focus limits our ability to draw general conclusions about the ways in which three-dimensional structures are encoded, and to integrate information from three-dimensional data to address a broader gamut of biological questions. Here, we generate a complete and gapless genome sequence for the filamentous fungus, Epichloë festucae. We use Hi-C data to examine the three-dimensional organisation of the genome, and RNA-seq data to investigate how Epichloë genome structure contributes to the suite of transcriptional changes needed to maintain symbiotic relationships with the grass host. Our results reveal a genome in which very repeat-rich blocks of DNA with discrete boundaries are interspersed by gene-rich sequences that are almost repeat-free. In contrast to other species reported to date, the three-dimensional structure of the genome is anchored by these repeat blocks, which act to isolate transcription in neighbouring gene-rich regions. Genes that are differentially expressed in planta are enriched near the boundaries of these repeat-rich blocks, suggesting that their three-dimensional orientation partly encodes and regulates the symbiotic relationship formed by this organism.
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Affiliation(s)
- David J. Winter
- Statistics and Bioinformatics Group, Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
- The Bio-Protection Research Centre, Massey University, Palmerston North, New Zealand
| | - Austen R. D. Ganley
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Carolyn A. Young
- Noble Research Institute, LLC, Ardmore, Oklahoma, United States of America
| | - Ivan Liachko
- Phase Genomics Inc, Seattle, Washington, United States of America
| | - Christopher L. Schardl
- Department of Plant Pathology, University of Kentucky, Lexington, Kentucky, United States of America
| | - Pierre-Yves Dupont
- Genetics Group, Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Daniel Berry
- Genetics Group, Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Arvina Ram
- Genetics Group, Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Barry Scott
- The Bio-Protection Research Centre, Massey University, Palmerston North, New Zealand
- Genetics Group, Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Murray P. Cox
- Statistics and Bioinformatics Group, Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand
- The Bio-Protection Research Centre, Massey University, Palmerston North, New Zealand
- * E-mail:
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16
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Rivera Y, Salgado-Salazar C, Veltri D, Malapi-Wight M, Crouch JA. Genome analysis of the ubiquitous boxwood pathogen Pseudonectria foliicola. PeerJ 2018; 6:e5401. [PMID: 30155349 PMCID: PMC6110257 DOI: 10.7717/peerj.5401] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Accepted: 07/18/2018] [Indexed: 01/15/2023] Open
Abstract
Boxwood (Buxus spp.) are broad-leaved, evergreen landscape plants valued for their longevity and ornamental qualities. Volutella leaf and stem blight, caused by the ascomycete fungi Pseudonectria foliicola and P. buxi, is one of the major diseases affecting the health and ornamental qualities of boxwood. Although this disease is less severe than boxwood blight caused by Calonectria pseudonaviculata and C. henricotiae, its widespread occurrence and disfiguring symptoms have caused substantial economic losses to the ornamental industry. In this study, we sequenced the genome of P. foliicola isolate ATCC13545 using Illumina technology and compared it to other publicly available fungal pathogen genomes to better understand the biology of this organism. A de novo assembly estimated the genome size of P. foliicola at 28.7 Mb (425 contigs; N50 = 184,987 bp; avg. coverage 188×), with just 9,272 protein-coding genes. To our knowledge, P. foliicola has the smallest known genome within the Nectriaceae. Consistent with the small size of the genome, the secretome, CAzyme and secondary metabolite profiles of this fungus are reduced relative to two other surveyed Nectriaceae fungal genomes: Dactylonectria macrodidyma JAC15-245 and Fusarium graminearum Ph-1. Interestingly, a large cohort of genes associated with reduced virulence and loss of pathogenicity was identified from the P. foliicola dataset. These data are consistent with the latest observations by plant pathologists that P. buxi and most likely P. foliicola, are opportunistic, latent pathogens that prey upon weak and stressed boxwood plants.
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Affiliation(s)
- Yazmín Rivera
- Mycology and Nematology Genetic Diversity and Biology Laboratory, US Department of Agriculture, Agriculture Research Service (USDA-ARS), Beltsville, MD, United States of America
- Department of Plant Biology and Pathology, Rutgers, The State University of New Jersey, New Brunswick, NJ, United States of America
- Current affiliation: Center for Plant Health, Science and Technology, USDA, Animal and Plant Health Inspection Service, Beltsville, MD, United States of America
| | - Catalina Salgado-Salazar
- Mycology and Nematology Genetic Diversity and Biology Laboratory, US Department of Agriculture, Agriculture Research Service (USDA-ARS), Beltsville, MD, United States of America
- Department of Plant Biology and Pathology, Rutgers, The State University of New Jersey, New Brunswick, NJ, United States of America
- ARS Research Participation Program, Oak Ridge Institute for Science and Education, Oak Ridge, TN, United States of America
| | - Daniel Veltri
- Mycology and Nematology Genetic Diversity and Biology Laboratory, US Department of Agriculture, Agriculture Research Service (USDA-ARS), Beltsville, MD, United States of America
- ARS Research Participation Program, Oak Ridge Institute for Science and Education, Oak Ridge, TN, United States of America
- Current affiliation: Bioinformatics and Computational Biosciences Branch, Office of Cyber Infrastructure and Computational Biology, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD, United States of America
| | - Martha Malapi-Wight
- Mycology and Nematology Genetic Diversity and Biology Laboratory, US Department of Agriculture, Agriculture Research Service (USDA-ARS), Beltsville, MD, United States of America
- Current affiliation: Plant Germplasm Quarantine Program, USDA, Animal and Plant Health Inspection Service, Beltsville, MD, United States of America
| | - Jo Anne Crouch
- Mycology and Nematology Genetic Diversity and Biology Laboratory, US Department of Agriculture, Agriculture Research Service (USDA-ARS), Beltsville, MD, United States of America
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Horns F, Petit E, Hood ME. Massive Expansion of Gypsy-Like Retrotransposons in Microbotryum Fungi. Genome Biol Evol 2018; 9:363-371. [PMID: 28164239 PMCID: PMC5381629 DOI: 10.1093/gbe/evx011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/30/2017] [Indexed: 12/11/2022] Open
Abstract
Transposable elements (TEs) are selfish, autonomously replicating DNA sequences that constitute a major component of eukaryotic genomes and contribute to genome evolution through their movement and amplification. Many fungal genomes, including the anther-smut fungi in the basidiomycete genus Microbotryum, have genome defense mechanisms, such as repeat-induced point mutation (RIP), which hypermutate repetitive DNA and limit TE activity. Little is known about how hypermutation affects the tempo of TE activity and their sequence evolution. Here we report the identification of a massive burst-like expansion of Gypsy-like retrotransposons in a strain of Microbotryum. This TE expansion evidently occurred in the face of RIP-like hypermutation activity. By examining the fitness of individual TE insertion variants, we found that RIP-like mutations impair TE fitness and limit proliferation. Our results provide evidence for a punctuated pattern of TE expansion in a fungal genome, similar to that observed in animals and plants. While targeted hypermutation is often thought of as an effective protection against mobile element activity, our findings suggest that active TEs can persist and undergo selection while they proliferate in genomes that have RIP-like defenses.
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Affiliation(s)
- Felix Horns
- Department of Biology, Amherst College, Amherst, MA
| | - Elsa Petit
- Department of Biology, Amherst College, Amherst, MA
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18
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Genome wide analysis of the transition to pathogenic lifestyles in Magnaporthales fungi. Sci Rep 2018; 8:5862. [PMID: 29651164 PMCID: PMC5897359 DOI: 10.1038/s41598-018-24301-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2018] [Accepted: 03/29/2018] [Indexed: 11/08/2022] Open
Abstract
The rice blast fungus Pyricularia oryzae (syn. Magnaporthe oryzae, Magnaporthe grisea), a member of the order Magnaporthales in the class Sordariomycetes, is an important plant pathogen and a model species for studying pathogen infection and plant-fungal interaction. In this study, we generated genome sequence data from five additional Magnaporthales fungi including non-pathogenic species, and performed comparative genome analysis of a total of 13 fungal species in the class Sordariomycetes to understand the evolutionary history of the Magnaporthales and of fungal pathogenesis. Our results suggest that the Magnaporthales diverged ca. 31 millon years ago from other Sordariomycetes, with the phytopathogenic blast clade diverging ca. 21 million years ago. Little evidence of inter-phylum horizontal gene transfer (HGT) was detected in Magnaporthales. In contrast, many genes underwent positive selection in this order and the majority of these sequences are clade-specific. The blast clade genomes contain more secretome and avirulence effector genes, which likely play key roles in the interaction between Pyricularia species and their plant hosts. Finally, analysis of transposable elements (TE) showed differing proportions of TE classes among Magnaporthales genomes, suggesting that species-specific patterns may hold clues to the history of host/environmental adaptation in these fungi.
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19
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Li WC, Chen CL, Wang TF. Repeat-induced point (RIP) mutation in the industrial workhorse fungus Trichoderma reesei. Appl Microbiol Biotechnol 2018; 102:1567-1574. [DOI: 10.1007/s00253-017-8731-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2017] [Revised: 12/18/2017] [Accepted: 12/20/2017] [Indexed: 02/01/2023]
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20
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Zaccaron AZ, Bluhm BH. The genome sequence of Bipolaris cookei reveals mechanisms of pathogenesis underlying target leaf spot of sorghum. Sci Rep 2017; 7:17217. [PMID: 29222463 PMCID: PMC5722872 DOI: 10.1038/s41598-017-17476-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Accepted: 11/24/2017] [Indexed: 11/23/2022] Open
Abstract
Bipolaris cookei (=Bipolaris sorghicola) causes target leaf spot, one of the most prevalent foliar diseases of sorghum. Little is known about the molecular basis of pathogenesis in B. cookei, in large part due to a paucity of resources for molecular genetics, such as a reference genome. Here, a draft genome sequence of B. cookei was obtained and analyzed. A hybrid assembly strategy utilizing Illumina and Pacific Biosciences sequencing technologies produced a draft nuclear genome of 36.1 Mb, organized into 321 scaffolds with L50 of 31 and N50 of 378 kb, from which 11,189 genes were predicted. Additionally, a finished mitochondrial genome sequence of 135,790 bp was obtained, which contained 75 predicted genes. Comparative genomics revealed that B. cookei possessed substantially fewer carbohydrate-active enzymes and secreted proteins than closely related Bipolaris species. Novel genes involved in secondary metabolism, including genes implicated in ophiobolin biosynthesis, were identified. Among 37 B. cookei genes induced during sorghum infection, one encodes a putative effector with a limited taxonomic distribution among plant pathogenic fungi. The draft genome sequence of B. cookei provided novel insights into target leaf spot of sorghum and is an important resource for future investigation.
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Affiliation(s)
- Alex Z Zaccaron
- Department of Plant Pathology, University of Arkansas, Division of Agriculture, Fayetteville, AR, 72701, USA
| | - Burton H Bluhm
- Department of Plant Pathology, University of Arkansas, Division of Agriculture, Fayetteville, AR, 72701, USA.
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21
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Li WC, Huang CH, Chen CL, Chuang YC, Tung SY, Wang TF. Trichoderma reesei complete genome sequence, repeat-induced point mutation, and partitioning of CAZyme gene clusters. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:170. [PMID: 28690679 PMCID: PMC5496416 DOI: 10.1186/s13068-017-0825-x] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Accepted: 05/22/2017] [Indexed: 05/13/2023]
Abstract
BACKGROUND Trichoderma reesei (Ascomycota, Pezizomycotina) QM6a is a model fungus for a broad spectrum of physiological phenomena, including plant cell wall degradation, industrial production of enzymes, light responses, conidiation, sexual development, polyketide biosynthesis, and plant-fungal interactions. The genomes of QM6a and its high enzyme-producing mutants have been sequenced by second-generation-sequencing methods and are publicly available from the Joint Genome Institute. While these genome sequences have offered useful information for genomic and transcriptomic studies, their limitations and especially their short read lengths make them poorly suited for some particular biological problems, including assembly, genome-wide determination of chromosome architecture, and genetic modification or engineering. RESULTS We integrated Pacific Biosciences and Illumina sequencing platforms for the highest-quality genome assembly yet achieved, revealing seven telomere-to-telomere chromosomes (34,922,528 bp; 10877 genes) with 1630 newly predicted genes and >1.5 Mb of new sequences. Most new sequences are located on AT-rich blocks, including 7 centromeres, 14 subtelomeres, and 2329 interspersed AT-rich blocks. The seven QM6a centromeres separately consist of 24 conserved repeats and 37 putative centromere-encoded genes. These findings open up a new perspective for future centromere and chromosome architecture studies. Next, we demonstrate that sexual crossing readily induced cytosine-to-thymine point mutations on both tandem and unlinked duplicated sequences. We also show by bioinformatic analysis that T. reesei has evolved a robust repeat-induced point mutation (RIP) system to accumulate AT-rich sequences, with longer AT-rich blocks having more RIP mutations. The widespread distribution of AT-rich blocks correlates genome-wide partitions with gene clusters, explaining why clustering of genes has been reported to not influence gene expression in T. reesei. CONCLUSION Compartmentation of ancestral gene clusters by AT-rich blocks might promote flexibilities that are evolutionarily advantageous in this fungus' soil habitats and other natural environments. Our analyses, together with the complete genome sequence, provide a better blueprint for biotechnological and industrial applications.
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Affiliation(s)
- Wan-Chen Li
- Taiwan International Graduate Program in Molecular and Cellular Biology, Academia Sinica, Taipei, 115 Taiwan
- Institute of Life Sciences, National Defense Medical Center, Taipei, 115 Taiwan
- Institute of Molecular Biology, Academia Sinica, Taipei, 115 Taiwan
| | - Chien-Hao Huang
- Institute of Molecular Biology, Academia Sinica, Taipei, 115 Taiwan
- Institute of Genome Sciences, National Yang-Ming University, Taipei, 112 Taiwan
| | - Chia-Ling Chen
- Institute of Molecular Biology, Academia Sinica, Taipei, 115 Taiwan
| | - Yu-Chien Chuang
- Institute of Molecular Biology, Academia Sinica, Taipei, 115 Taiwan
| | - Shu-Yun Tung
- Institute of Molecular Biology, Academia Sinica, Taipei, 115 Taiwan
| | - Ting-Fang Wang
- Taiwan International Graduate Program in Molecular and Cellular Biology, Academia Sinica, Taipei, 115 Taiwan
- Institute of Molecular Biology, Academia Sinica, Taipei, 115 Taiwan
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22
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Dang Y, Cheng J, Sun X, Zhou Z, Liu Y. Antisense transcription licenses nascent transcripts to mediate transcriptional gene silencing. Genes Dev 2016; 30:2417-2432. [PMID: 27856616 PMCID: PMC5131781 DOI: 10.1101/gad.285791.116] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 10/21/2016] [Indexed: 12/21/2022]
Abstract
In this study, Dang et al. use Neurospora to demonstrate a critical role for transcription kinetics in long noncoding RNA-mediated epigenetic modifications and identify ERI-1 as an important regulator of cotranscriptional gene silencing and post-transcriptional RNA metabolism. In eukaryotes, antisense transcription can regulate sense transcription by induction of epigenetic modifications. We showed previously that antisense transcription triggers Dicer-independent siRNA (disiRNA) production and disiRNA locus DNA methylation (DLDM) in Neurospora crassa. Here we show that the conserved exonuclease ERI-1 (enhanced RNAi-1) is a critical component in this process. Antisense transcription and ERI-1 binding to target RNAs are necessary and sufficient to trigger DLDM. Convergent transcription causes stalling of RNA polymerase II during transcription, which permits ERI-1 to bind nascent RNAs in the nucleus and recruit a histone methyltransferase complex that catalyzes chromatin modifications. Furthermore, we show that, in the cytoplasm, ERI-1 targets hundreds of transcripts from loci without antisense transcription to regulate RNA stability. Together, our results demonstrate a critical role for transcription kinetics in long noncoding RNA-mediated epigenetic modifications and identify ERI-1 as an important regulator of cotranscriptional gene silencing and post-transcriptional RNA metabolism.
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Affiliation(s)
- Yunkun Dang
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Jiasen Cheng
- State Key Laboratory of Agricultural Microbiology, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, Hubei 430070, China
| | - Xianyun Sun
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, ZhongGuanCun, Beijing 100080, China
| | - Zhipeng Zhou
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Yi Liu
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
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Codon usage is an important determinant of gene expression levels largely through its effects on transcription. Proc Natl Acad Sci U S A 2016; 113:E6117-E6125. [PMID: 27671647 DOI: 10.1073/pnas.1606724113] [Citation(s) in RCA: 247] [Impact Index Per Article: 30.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Codon usage biases are found in all eukaryotic and prokaryotic genomes, and preferred codons are more frequently used in highly expressed genes. The effects of codon usage on gene expression were previously thought to be mainly mediated by its impacts on translation. Here, we show that codon usage strongly correlates with both protein and mRNA levels genome-wide in the filamentous fungus Neurospora Gene codon optimization also results in strong up-regulation of protein and RNA levels, suggesting that codon usage is an important determinant of gene expression. Surprisingly, we found that the impact of codon usage on gene expression results mainly from effects on transcription and is largely independent of mRNA translation and mRNA stability. Furthermore, we show that histone H3 lysine 9 trimethylation is one of the mechanisms responsible for the codon usage-mediated transcriptional silencing of some genes with nonoptimal codons. Together, these results uncovered an unexpected important role of codon usage in ORF sequences in determining transcription levels and suggest that codon biases are an adaptation of protein coding sequences to both transcription and translation machineries. Therefore, synonymous codons not only specify protein sequences and translation dynamics, but also help determine gene expression levels.
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Mark K, Cornejo C, Keller C, Flück D, Scheidegger C. Barcoding lichen-forming fungi using 454 pyrosequencing is challenged by artifactual and biological sequence variation. Genome 2016; 59:685-704. [DOI: 10.1139/gen-2015-0189] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Although lichens (lichen-forming fungi) play an important role in the ecological integrity of many vulnerable landscapes, only a minority of lichen-forming fungi have been barcoded out of the currently accepted ∼18 000 species. Regular Sanger sequencing can be problematic when analyzing lichens since saprophytic, endophytic, and parasitic fungi live intimately admixed, resulting in low-quality sequencing reads. Here, high-throughput, long-read 454 pyrosequencing in a GS FLX+ System was tested to barcode the fungal partner of 100 epiphytic lichen species from Switzerland using fungal-specific primers when amplifying the full internal transcribed spacer region (ITS). The present study shows the potential of DNA barcoding using pyrosequencing, in that the expected lichen fungus was successfully sequenced for all samples except one. Alignment solutions such as BLAST were found to be largely adequate for the generated long reads. In addition, the NCBI nucleotide database—currently the most complete database for lichen-forming fungi—can be used as a reference database when identifying common species, since the majority of analyzed lichens were identified correctly to the species or at least to the genus level. However, several issues were encountered, including a high sequencing error rate, multiple ITS versions in a genome (incomplete concerted evolution), and in some samples the presence of mixed lichen-forming fungi (possible lichen chimeras).
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Affiliation(s)
- Kristiina Mark
- Biodiversity and Conservation Biology, Swiss Federal Research Institute WSL, Switzerland
- Institute of Botany and Ecology, University of Tartu, Estonia
| | - Carolina Cornejo
- Biodiversity and Conservation Biology, Swiss Federal Research Institute WSL, Switzerland
| | - Christine Keller
- Biodiversity and Conservation Biology, Swiss Federal Research Institute WSL, Switzerland
| | - Daniela Flück
- Biodiversity and Conservation Biology, Swiss Federal Research Institute WSL, Switzerland
| | - Christoph Scheidegger
- Biodiversity and Conservation Biology, Swiss Federal Research Institute WSL, Switzerland
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Goldfarb M, Santana MF, Salomão TMF, Queiroz MVD, Barros EGD. Evidence of ectopic recombination and a repeat-induced point (RIP) mutation in the genome of Sclerotinia sclerotiorum, the agent responsible for white mold. Genet Mol Biol 2016; 39:426-30. [PMID: 27560652 PMCID: PMC5004834 DOI: 10.1590/1678-4685-gmb-2015-0241] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2015] [Accepted: 12/20/2015] [Indexed: 12/24/2022] Open
Abstract
Two retrotransposons from the superfamilies Copia and
Gypsy named as Copia-LTR_SS and
Gypsy-LTR_SS, respectively, were identified in
the genomic bank of Sclerotinia sclerotiorum. These transposable
elements (TEs) contained direct and preserved long terminal repeats (LTR). Domains
related to codified regions for gag protein, integrase, reverse transcriptase and
RNAse H were identified in Copia-LTR_SS, whereas in
Gypsy-LTR_SS only domains for gag, reverse
transcriptase and RNAse H were found. The abundance of identified LTR-Solo suggested
possible genetic recombination events in the S. sclerotiorum genome.
Furthermore, alignment of the sequences for LTR elements from each superfamily
suggested the presence of a RIP (repeat-induced point mutation) silencing mechanism
that may directly affect the evolution of this species.
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Affiliation(s)
- Míriam Goldfarb
- Laboratório de Biologia Molecular de Plantas, Instituto de Biotecnologia Aplicada (BIOAGRO), Universidade Federal de Viçosa (UFV), 36570-000, Viçosa, MG, Brazil
| | - Mateus Ferreira Santana
- Laboratório de Genética Molecular e de Microrganismo, Instituto de Biotecnologia Aplicada (BIOAGRO), Universidade Federal de Viçosa (UFV), 36570-000, Viçosa, MG, Brazil
| | - Tânia Maria Fernandes Salomão
- Laboratório de Biologia Molecular de Insetos, Departamento de Biologia Geral, Universidade Federal de Viçosa (UFV), 36570-000, Viçosa, MG, Brazil
| | - Marisa Vieira de Queiroz
- Laboratório de Genética Molecular e de Microrganismo, Instituto de Biotecnologia Aplicada (BIOAGRO), Universidade Federal de Viçosa (UFV), 36570-000, Viçosa, MG, Brazil
| | - Everaldo Gonçalves de Barros
- Laboratório de Ciências Genômicas e Biotecnologia, Universidade Católica de Brasília, 70790-160, Brasília, DF, Brazil
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de Man TJB, Stajich JE, Kubicek CP, Teiling C, Chenthamara K, Atanasova L, Druzhinina IS, Levenkova N, Birnbaum SSL, Barribeau SM, Bozick BA, Suen G, Currie CR, Gerardo NM. Small genome of the fungus Escovopsis weberi, a specialized disease agent of ant agriculture. Proc Natl Acad Sci U S A 2016; 113:3567-72. [PMID: 26976598 PMCID: PMC4822581 DOI: 10.1073/pnas.1518501113] [Citation(s) in RCA: 49] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Many microorganisms with specialized lifestyles have reduced genomes. This is best understood in beneficial bacterial symbioses, where partner fidelity facilitates loss of genes necessary for living independently. Specialized microbial pathogens may also exhibit gene loss relative to generalists. Here, we demonstrate that Escovopsis weberi, a fungal parasite of the crops of fungus-growing ants, has a reduced genome in terms of both size and gene content relative to closely related but less specialized fungi. Although primary metabolism genes have been retained, the E. weberi genome is depleted in carbohydrate active enzymes, which is consistent with reliance on a host with these functions. E. weberi has also lost genes considered necessary for sexual reproduction. Contrasting these losses, the genome encodes unique secondary metabolite biosynthesis clusters, some of which include genes that exhibit up-regulated expression during host attack. Thus, the specialized nature of the interaction between Escovopsis and ant agriculture is reflected in the parasite's genome.
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Affiliation(s)
- Tom J B de Man
- Department of Biology, Emory University, Atlanta, GA 30322
| | - Jason E Stajich
- Department of Plant Pathology and Microbiology, University of California, Riverside, CA 92521
| | - Christian P Kubicek
- Institute of Chemical Engineering, Vienna University of Technology, 1060 Vienna, Austria
| | | | - Komal Chenthamara
- Institute of Chemical Engineering, Vienna University of Technology, 1060 Vienna, Austria
| | - Lea Atanasova
- Institute of Chemical Engineering, Vienna University of Technology, 1060 Vienna, Austria
| | - Irina S Druzhinina
- Institute of Chemical Engineering, Vienna University of Technology, 1060 Vienna, Austria
| | | | | | - Seth M Barribeau
- Department of Biology, Emory University, Atlanta, GA 30322; Department of Biology, East Carolina University, Greenville, NC 27858
| | | | - Garret Suen
- Department of Bacteriology, University of Wisconsin, Madison, WI 53706
| | - Cameron R Currie
- Department of Bacteriology, University of Wisconsin, Madison, WI 53706
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A Novel Type Pathway-Specific Regulator and Dynamic Genome Environments of a Solanapyrone Biosynthesis Gene Cluster in the Fungus Ascochyta rabiei. EUKARYOTIC CELL 2015; 14:1102-13. [PMID: 26342019 PMCID: PMC4621316 DOI: 10.1128/ec.00084-15] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 08/31/2015] [Indexed: 01/07/2023]
Abstract
Secondary metabolite genes are often clustered together and situated in particular genomic regions, like the subtelomere, that can facilitate niche adaptation in fungi. Solanapyrones are toxic secondary metabolites produced by fungi occupying different ecological niches. Full-genome sequencing of the ascomycete Ascochyta rabiei revealed a solanapyrone biosynthesis gene cluster embedded in an AT-rich region proximal to a telomere end and surrounded by Tc1/Mariner-type transposable elements. The highly AT-rich environment of the solanapyrone cluster is likely the product of repeat-induced point mutations. Several secondary metabolism-related genes were found in the flanking regions of the solanapyrone cluster. Although the solanapyrone cluster appears to be resistant to repeat-induced point mutations, a P450 monooxygenase gene adjacent to the cluster has been degraded by such mutations. Among the six solanapyrone cluster genes (sol1 to sol6), sol4 encodes a novel type of Zn(II)2Cys6 zinc cluster transcription factor. Deletion of sol4 resulted in the complete loss of solanapyrone production but did not compromise growth, sporulation, or virulence. Gene expression studies with the sol4 deletion and sol4-overexpressing mutants delimited the boundaries of the solanapyrone gene cluster and revealed that sol4 is likely a specific regulator of solanapyrone biosynthesis and appears to be necessary and sufficient for induction of the solanapyrone cluster genes. Despite the dynamic surrounding genomic regions, the solanapyrone gene cluster has maintained its integrity, suggesting important roles of solanapyrones in fungal biology.
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28
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Mutairi AOA, Low HC. p-Value for two-Sample Linear Rank Tests Using Permutation Simulations and the Normal Approximation Method. COMMUN STAT-SIMUL C 2015. [DOI: 10.1080/03610918.2013.794287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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29
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Calculating RIP Mutation in Fungal Genomes Using RIPCAL. Fungal Biol 2015. [DOI: 10.1007/978-3-319-10503-1_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Wang YY, Liu B, Zhang XY, Zhou QM, Zhang T, Li H, Yu YF, Zhang XL, Hao XY, Wang M, Wang L, Wei JC. Genome characteristics reveal the impact of lichenization on lichen-forming fungus Endocarpon pusillum Hedwig (Verrucariales, Ascomycota). BMC Genomics 2014; 15:34. [PMID: 24438332 PMCID: PMC3897900 DOI: 10.1186/1471-2164-15-34] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2013] [Accepted: 01/14/2014] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Lichen is a classic mutualistic organism and the lichenization is one of the fungal symbioses. The lichen-forming fungus Endocarpon pusillum is living in symbiosis with the green alga Diplosphaera chodatii Bialsuknia as a lichen in the arid regions. RESULTS 454 and Illumina technologies were used to sequence the genome of E. pusillum. A total of 9,285 genes were annotated in the 37.5 Mb genome of E. pusillum. Analyses of the genes provided direct molecular evidence for certain natural characteristics, such as homothallic reproduction and drought-tolerance. Comparative genomics analysis indicated that the expansion and contraction of some protein families in the E. pusillum genome reflect the specific relationship with its photosynthetic partner (D. chodatii). Co-culture experiments using the lichen-forming fungus E. pusillum and its algal partner allowed the functional identification of genes involved in the nitrogen and carbon transfer between both symbionts, and three lectins without signal peptide domains were found to be essential for the symbiotic recognition in the lichen; interestingly, the ratio of the biomass of both lichen-forming fungus and its photosynthetic partner and their contact time were found to be important for the interaction between these two symbionts. CONCLUSIONS The present study lays a genomic analysis of the lichen-forming fungus E. pusillum for demonstrating its general biological features and the traits of the interaction between this fungus and its photosynthetic partner D. chodatii, and will provide research basis for investigating the nature of its drought resistance and symbiosis.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Lei Wang
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
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Traeger S, Altegoer F, Freitag M, Gabaldon T, Kempken F, Kumar A, Marcet-Houben M, Pöggeler S, Stajich JE, Nowrousian M. The genome and development-dependent transcriptomes of Pyronema confluens: a window into fungal evolution. PLoS Genet 2013; 9:e1003820. [PMID: 24068976 PMCID: PMC3778014 DOI: 10.1371/journal.pgen.1003820] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2013] [Accepted: 08/07/2013] [Indexed: 11/26/2022] Open
Abstract
Fungi are a large group of eukaryotes found in nearly all ecosystems. More than 250 fungal genomes have already been sequenced, greatly improving our understanding of fungal evolution, physiology, and development. However, for the Pezizomycetes, an early-diverging lineage of filamentous ascomycetes, there is so far only one genome available, namely that of the black truffle, Tuber melanosporum, a mycorrhizal species with unusual subterranean fruiting bodies. To help close the sequence gap among basal filamentous ascomycetes, and to allow conclusions about the evolution of fungal development, we sequenced the genome and assayed transcriptomes during development of Pyronema confluens, a saprobic Pezizomycete with a typical apothecium as fruiting body. With a size of 50 Mb and ∼13,400 protein-coding genes, the genome is more characteristic of higher filamentous ascomycetes than the large, repeat-rich truffle genome; however, some typical features are different in the P. confluens lineage, e.g. the genomic environment of the mating type genes that is conserved in higher filamentous ascomycetes, but only partly conserved in P. confluens. On the other hand, P. confluens has a full complement of fungal photoreceptors, and expression studies indicate that light perception might be similar to distantly related ascomycetes and, thus, represent a basic feature of filamentous ascomycetes. Analysis of spliced RNA-seq sequence reads allowed the detection of natural antisense transcripts for 281 genes. The P. confluens genome contains an unusually high number of predicted orphan genes, many of which are upregulated during sexual development, consistent with the idea of rapid evolution of sex-associated genes. Comparative transcriptomics identified the transcription factor gene pro44 that is upregulated during development in P. confluens and the Sordariomycete Sordaria macrospora. The P. confluens pro44 gene (PCON_06721) was used to complement the S. macrospora pro44 deletion mutant, showing functional conservation of this developmental regulator. Fungi are a morphologically and physiologically diverse group of organisms with huge impacts on nearly all ecosystems. In recent years, genomes of many fungal species have been sequenced and have greatly improved our understanding of fungal biology. Ascomycetes are the largest fungal group with the highest number of sequenced genomes; however, for the Pezizales, an early-diverging lineage of filamentous ascomycetes, only one genome has been sequence to date, namely that of the black truffle. While truffles are among the most valuable edible fungi, they have a specialized life style as plant symbionts producing belowground fruiting bodies; thus it is difficult to draw conclusions about basal ascomycetes from one truffle genome alone. Therefore, we have sequenced the genome and several transcriptomes of the basal ascomycete Pyronema confluens, which has a saprobic life style typical of many ascomycetes. Comparisons with other fungal genomes showed that P. confluens has two conserved mating type genes, but that the genomic environment of the mating type genes is different from that of higher ascomycetes. We also found that a high number of orphan genes, i.e. genes without homologs in other fungi, are upregulated during sexual development. This is consistent with rapid evolution of sex-associated genes.
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Affiliation(s)
- Stefanie Traeger
- Lehrstuhl für Allgemeine und Molekulare Botanik, Ruhr-Universität Bochum, Bochum, Germany
| | - Florian Altegoer
- Lehrstuhl für Allgemeine und Molekulare Botanik, Ruhr-Universität Bochum, Bochum, Germany
| | - Michael Freitag
- Center for Genome Research and Biocomputing, Department of Biochemistry and Biophysics, Oregon State University, Corvallis, Oregon, United States of America
| | - Toni Gabaldon
- Centre for Genomic Regulation (CRG), Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Frank Kempken
- Abteilung Botanische Genetik und Molekularbiologie, Botanisches Institut und Botanischer Garten, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Abhishek Kumar
- Abteilung Botanische Genetik und Molekularbiologie, Botanisches Institut und Botanischer Garten, Christian-Albrechts-Universität zu Kiel, Kiel, Germany
| | - Marina Marcet-Houben
- Centre for Genomic Regulation (CRG), Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
| | - Stefanie Pöggeler
- Institute of Microbiology and Genetics, Department of Genetics of Eukaryotic Microorganisms, Georg-August University, Göttingen, Germany
| | - Jason E. Stajich
- Department of Plant Pathology and Microbiology, University of California Riverside, Riverside, California, United States of America
| | - Minou Nowrousian
- Lehrstuhl für Allgemeine und Molekulare Botanik, Ruhr-Universität Bochum, Bochum, Germany
- * E-mail:
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Dang Y, Li L, Guo W, Xue Z, Liu Y. Convergent transcription induces dynamic DNA methylation at disiRNA loci. PLoS Genet 2013; 9:e1003761. [PMID: 24039604 PMCID: PMC3764098 DOI: 10.1371/journal.pgen.1003761] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Accepted: 07/15/2013] [Indexed: 11/19/2022] Open
Abstract
Cytosine methylation of DNA is an important epigenetic gene silencing mechanism in plants, fungi, and animals. In the filamentous fungus Neurospora crassa, nearly all known DNA methylations occur in transposon relics and repetitive sequences, and DNA methylation does not depend on the canonical RNAi pathway. disiRNAs are Dicer-independent small non-coding RNAs that arise from gene-rich part of the Neurospora genome. Here we describe a new type of DNA methylation that is associated with the disiRNA loci. Unlike the known DNA methylation in Neurospora, disiRNA loci DNA methylation (DLDM) is highly dynamic and is regulated by an on/off mechanism. Some disiRNA production appears to rely on pol II directed transcription. Importantly, DLDM is triggered by convergent transcription and enriched in promoter regions. Together, our results establish a new mechanism that triggers DNA methylation. DNA methylation in eukayrotes refers to the modification of cytidines at 5th position with methyl group (5mC). Though absent in some species, DNA methylation is conserved across fungi, plants and animals and plays a critical role in X chromosome inactivation, genomic imprinting, transposon silencing etc. In addition, DNA methylation also occurs at the promoter sequence to regulate gene expression. Filamentous fungus Neurospora crassa has a well-known mechanism of DNA methylation for genomic defense. During sexual stage repetitive sequences (e.g. transposons) are recognized and point mutations are introduced. During vegetative stage these mutations serve as signals for establishing static DNA methylation to silence all copies of the sequences. In this study, we report a new type of DNA methylation in Neurospora. It is tightly linked to a type of non-coding small RNA termed dicer-independent siRNA (disiRNA) and therefore was termed disiRNA loci DNA methylation (DLDM). DLDM is dynamic regulated and shows an on/off pattern, i.e. most alleles contain no 5mC but some are densely methylated. Interestingly, DLDM can be triggered by convergent transcription and is accumulated at promoter regions. In summary, our findings demonstrate a new type of dynamic DNA methylation.
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Affiliation(s)
- Yunkun Dang
- Department of Physiology, The University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Liande Li
- Department of Physiology, The University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Wei Guo
- Department of Physiology, The University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Zhihong Xue
- Department of Physiology, The University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Yi Liu
- Department of Physiology, The University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- * E-mail:
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Schardl CL, Young CA, Hesse U, Amyotte SG, Andreeva K, Calie PJ, Fleetwood DJ, Haws DC, Moore N, Oeser B, Panaccione DG, Schweri KK, Voisey CR, Farman ML, Jaromczyk JW, Roe BA, O'Sullivan DM, Scott B, Tudzynski P, An Z, Arnaoudova EG, Bullock CT, Charlton ND, Chen L, Cox M, Dinkins RD, Florea S, Glenn AE, Gordon A, Güldener U, Harris DR, Hollin W, Jaromczyk J, Johnson RD, Khan AK, Leistner E, Leuchtmann A, Li C, Liu J, Liu J, Liu M, Mace W, Machado C, Nagabhyru P, Pan J, Schmid J, Sugawara K, Steiner U, Takach JE, Tanaka E, Webb JS, Wilson EV, Wiseman JL, Yoshida R, Zeng Z. Plant-symbiotic fungi as chemical engineers: multi-genome analysis of the clavicipitaceae reveals dynamics of alkaloid loci. PLoS Genet 2013; 9:e1003323. [PMID: 23468653 PMCID: PMC3585121 DOI: 10.1371/journal.pgen.1003323] [Citation(s) in RCA: 271] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2012] [Accepted: 12/31/2012] [Indexed: 01/01/2023] Open
Abstract
The fungal family Clavicipitaceae includes plant symbionts and parasites that produce several psychoactive and bioprotective alkaloids. The family includes grass symbionts in the epichloae clade (Epichloë and Neotyphodium species), which are extraordinarily diverse both in their host interactions and in their alkaloid profiles. Epichloae produce alkaloids of four distinct classes, all of which deter insects, and some-including the infamous ergot alkaloids-have potent effects on mammals. The exceptional chemotypic diversity of the epichloae may relate to their broad range of host interactions, whereby some are pathogenic and contagious, others are mutualistic and vertically transmitted (seed-borne), and still others vary in pathogenic or mutualistic behavior. We profiled the alkaloids and sequenced the genomes of 10 epichloae, three ergot fungi (Claviceps species), a morning-glory symbiont (Periglandula ipomoeae), and a bamboo pathogen (Aciculosporium take), and compared the gene clusters for four classes of alkaloids. Results indicated a strong tendency for alkaloid loci to have conserved cores that specify the skeleton structures and peripheral genes that determine chemical variations that are known to affect their pharmacological specificities. Generally, gene locations in cluster peripheries positioned them near to transposon-derived, AT-rich repeat blocks, which were probably involved in gene losses, duplications, and neofunctionalizations. The alkaloid loci in the epichloae had unusual structures riddled with large, complex, and dynamic repeat blocks. This feature was not reflective of overall differences in repeat contents in the genomes, nor was it characteristic of most other specialized metabolism loci. The organization and dynamics of alkaloid loci and abundant repeat blocks in the epichloae suggested that these fungi are under selection for alkaloid diversification. We suggest that such selection is related to the variable life histories of the epichloae, their protective roles as symbionts, and their associations with the highly speciose and ecologically diverse cool-season grasses.
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Santana MF, Silva JCF, Batista AD, Ribeiro LE, da Silva GF, de Araújo EF, de Queiroz MV. Abundance, distribution and potential impact of transposable elements in the genome of Mycosphaerella fijiensis. BMC Genomics 2012; 13:720. [PMID: 23260030 PMCID: PMC3562529 DOI: 10.1186/1471-2164-13-720] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Accepted: 12/20/2012] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Mycosphaerella fijiensis is a ascomycete that causes Black Sigatoka in bananas. Recently, the M. fijiensis genome was sequenced. Repetitive sequences are ubiquitous components of fungal genomes. In most genomic analyses, repetitive sequences are associated with transposable elements (TEs). TEs are dispersed repetitive DNA sequences found in a host genome. These elements have the ability to move from one location to another within the genome, and their insertion can cause a wide spectrum of mutations in their hosts. Some of the deleterious effects of TEs may be due to ectopic recombination among TEs of the same family. In addition, some transposons are physically linked to genes and can control their expression. To prevent possible damage caused by the presence of TEs in the genome, some fungi possess TE-silencing mechanisms, such as RIP (Repeat Induced Point mutation). In this study, the abundance, distribution and potential impact of TEs in the genome of M. fijiensis were investigated. RESULTS A total of 613 LTR-Gypsy and 27 LTR-Copia complete elements of the class I were detected. Among the class II elements, a total of 28 Mariner, five Mutator and one Harbinger complete elements were identified. The results of this study indicate that transposons were and are important ectopic recombination sites. A distribution analysis of a transposable element from each class of the M. fijiensis isolates revealed variable hybridization profiles, indicating the activity of these elements. Several genes encoding proteins involved in important metabolic pathways and with potential correlation to pathogenicity systems were identified upstream and downstream of transposable elements. A comparison of the sequences from different transposon groups suggested the action of the RIP silencing mechanism in the genome of this microorganism. CONCLUSIONS The analysis of TEs in M. fijiensis suggests that TEs play an important role in the evolution of this organism because the activity of these elements, as well as the rearrangements caused by ectopic recombination, can result in deletion, duplication, inversion and translocation. Some of these changes can potentially modify gene structure or expression and, thus, facilitate the emergence of new strains of this pathogen.
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Affiliation(s)
- Mateus F Santana
- Present address: Laboratório de Genética Molecular e de Microrganismo, Universidade Federal de Viçosa, Viçosa, Brazil
| | - José CF Silva
- Present address: Diretoria de Tecnologia da Informação, Universidade Federal de Viçosa, Viçosa, Brazil
| | - Aline D Batista
- Present address: Laboratório de Genética Molecular e de Microrganismo, Universidade Federal de Viçosa, Viçosa, Brazil
| | - Lílian E Ribeiro
- Present address: Laboratório de Genética Molecular e de Microrganismo, Universidade Federal de Viçosa, Viçosa, Brazil
| | | | - Elza F de Araújo
- Present address: Laboratório de Genética Molecular e de Microrganismo, Universidade Federal de Viçosa, Viçosa, Brazil
| | - Marisa V de Queiroz
- Present address: Laboratório de Genética Molecular e de Microrganismo, Universidade Federal de Viçosa, Viçosa, Brazil
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Ohm RA, Feau N, Henrissat B, Schoch CL, Horwitz BA, Barry KW, Condon BJ, Copeland AC, Dhillon B, Glaser F, Hesse CN, Kosti I, LaButti K, Lindquist EA, Lucas S, Salamov AA, Bradshaw RE, Ciuffetti L, Hamelin RC, Kema GHJ, Lawrence C, Scott JA, Spatafora JW, Turgeon BG, de Wit PJGM, Zhong S, Goodwin SB, Grigoriev IV. Diverse lifestyles and strategies of plant pathogenesis encoded in the genomes of eighteen Dothideomycetes fungi. PLoS Pathog 2012; 8:e1003037. [PMID: 23236275 PMCID: PMC3516569 DOI: 10.1371/journal.ppat.1003037] [Citation(s) in RCA: 372] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Accepted: 09/30/2012] [Indexed: 12/21/2022] Open
Abstract
The class Dothideomycetes is one of the largest groups of fungi with a high level of ecological diversity including many plant pathogens infecting a broad range of hosts. Here, we compare genome features of 18 members of this class, including 6 necrotrophs, 9 (hemi)biotrophs and 3 saprotrophs, to analyze genome structure, evolution, and the diverse strategies of pathogenesis. The Dothideomycetes most likely evolved from a common ancestor more than 280 million years ago. The 18 genome sequences differ dramatically in size due to variation in repetitive content, but show much less variation in number of (core) genes. Gene order appears to have been rearranged mostly within chromosomal boundaries by multiple inversions, in extant genomes frequently demarcated by adjacent simple repeats. Several Dothideomycetes contain one or more gene-poor, transposable element (TE)-rich putatively dispensable chromosomes of unknown function. The 18 Dothideomycetes offer an extensive catalogue of genes involved in cellulose degradation, proteolysis, secondary metabolism, and cysteine-rich small secreted proteins. Ancestors of the two major orders of plant pathogens in the Dothideomycetes, the Capnodiales and Pleosporales, may have had different modes of pathogenesis, with the former having fewer of these genes than the latter. Many of these genes are enriched in proximity to transposable elements, suggesting faster evolution because of the effects of repeat induced point (RIP) mutations. A syntenic block of genes, including oxidoreductases, is conserved in most Dothideomycetes and upregulated during infection in L. maculans, suggesting a possible function in response to oxidative stress. Dothideomycetes is the largest and most ecologically diverse class of fungi that includes many plant pathogens with high economic impact. Currently 18 genome sequences of Dothideomycetes are available, 14 of which are newly described in this paper and in several companion papers, allowing unprecedented resolution in comparative analyses. These 18 organisms have diverse lifestyles and strategies of plant pathogenesis. Three feed on dead organic matter only, six are necrotrophs (killing the host plant cells), one is a biotroph (forming an association with and thus feeding on the living cells of the host plant cells) and 8 are hemibiotrophs (having an initial biotrophic stage, and killing the host plant at a later stage). These various lifestyles are also reflected in the gene sets present in each group. For example, sets of genes involved in carbohydrate degradation and secondary metabolism are expanded in necrotrophs. Many genes involved in pathogenesis are located near repetitive sequences, which are believed to speed up their evolution. Blocks of genes with conserved gene order were identified. In addition to this we deduce that the mechanism for mesosynteny, a type of genome evolution particular to Dothideomycetes, is by intra-chromosomal inversions.
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Affiliation(s)
- Robin A. Ohm
- United States Department of Energy (DOE) Joint Genome Institute (JGI), Walnut Creek, California, United States of America
- * E-mail: (RAO); (IVG)
| | - Nicolas Feau
- Faculty of Forestry, Forest Sciences Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Bernard Henrissat
- Architecture et Fonction des Macromolécules Biologiques, Aix-Marseille Université, CNRS, Marseille, France
| | | | | | - Kerrie W. Barry
- United States Department of Energy (DOE) Joint Genome Institute (JGI), Walnut Creek, California, United States of America
| | - Bradford J. Condon
- Department of Plant Pathology & Plant-Microbe Biology, Cornell University, Ithaca, New York, United States of America
| | - Alex C. Copeland
- United States Department of Energy (DOE) Joint Genome Institute (JGI), Walnut Creek, California, United States of America
| | - Braham Dhillon
- Faculty of Forestry, Forest Sciences Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Fabian Glaser
- Bioinformatics Knowledge Unit, Technion - IIT, Haifa, Israel
| | - Cedar N. Hesse
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, United States of America
| | - Idit Kosti
- Department of Biology, Technion - IIT, Haifa, Israel
| | - Kurt LaButti
- United States Department of Energy (DOE) Joint Genome Institute (JGI), Walnut Creek, California, United States of America
| | - Erika A. Lindquist
- United States Department of Energy (DOE) Joint Genome Institute (JGI), Walnut Creek, California, United States of America
| | - Susan Lucas
- United States Department of Energy (DOE) Joint Genome Institute (JGI), Walnut Creek, California, United States of America
| | - Asaf A. Salamov
- United States Department of Energy (DOE) Joint Genome Institute (JGI), Walnut Creek, California, United States of America
| | - Rosie E. Bradshaw
- Institute of Molecular BioSciences, Massey University, Palmerston North, New Zealand
| | - Lynda Ciuffetti
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, United States of America
| | - Richard C. Hamelin
- Faculty of Forestry, Forest Sciences Centre, University of British Columbia, Vancouver, British Columbia, Canada
- Natural Resources Canada, Ste-Foy, Quebec, Canada
| | | | - Christopher Lawrence
- Virginia Bioinformatics Institute & Department of Biological Sciences, Blacksburg, Virginia, United States of America
| | - James A. Scott
- Division of Occupational & Environmental Health, Dalla Lana School of Public Health, University of Toronto, Toronto, Canada
| | - Joseph W. Spatafora
- Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, United States of America
| | - B. Gillian Turgeon
- Department of Plant Pathology & Plant-Microbe Biology, Cornell University, Ithaca, New York, United States of America
| | | | - Shaobin Zhong
- Department of Plant Pathology, North Dakota State University, Fargo, North Dakota, United States of America
| | - Stephen B. Goodwin
- United States Department of Agriculture, Agricultural Research Service, Purdue University, West Lafayette, Indiana, United States of America
| | - Igor V. Grigoriev
- United States Department of Energy (DOE) Joint Genome Institute (JGI), Walnut Creek, California, United States of America
- * E-mail: (RAO); (IVG)
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Heterochromatin protein 1 forms distinct complexes to direct histone deacetylation and DNA methylation. Nat Struct Mol Biol 2012; 19:471-7, S1. [PMID: 22504884 DOI: 10.1038/nsmb.2274] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2012] [Accepted: 03/05/2012] [Indexed: 11/09/2022]
Abstract
DNA methylation, methylation of histone H3 at Lys9 (H3K9me3) and hypoacetylated histones are common molecular features of heterochromatin. Important details of their functions and inter-relationships remain unclear, however. In Neurospora crassa, H3K9me3 directs DNA methylation through a complex containing heterochromatin protein 1 (HP1) and the DNA methyltransferase DIM-2. We identified a distinct HP1 complex, HP1, CDP-2, HDA-1 and CHAP (HCHC), and found that it is responsible for silencing independently of DNA methylation. HCHC defects cause hyperacetylation of centromeric histones, greater accessibility of DIM-2 and hypermethylation of centromeric DNA. Loss of HCHC also causes mislocalization of the DIM-5 H3K9 methyltransferase at a subset of interstitial methylated regions, leading to selective DNA hypomethylation. We demonstrate that HP1 forms distinct DNA methylation and histone deacetylation complexes that work in parallel to assemble silent chromatin in N. crassa.
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Liu SY, Lin JQ, Wu HL, Wang CC, Huang SJ, Luo YF, Sun JH, Zhou JX, Yan SJ, He JG, Wang J, He ZM. Bisulfite sequencing reveals that Aspergillus flavus holds a hollow in DNA methylation. PLoS One 2012; 7:e30349. [PMID: 22276181 PMCID: PMC3262820 DOI: 10.1371/journal.pone.0030349] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Accepted: 12/14/2011] [Indexed: 12/12/2022] Open
Abstract
Aspergillus flavus first gained scientific attention for its production of aflatoxin. The underlying regulation of aflatoxin biosynthesis has been serving as a theoretical model for biosynthesis of other microbial secondary metabolites. Nevertheless, for several decades, the DNA methylation status, one of the important epigenomic modifications involved in gene regulation, in A. flavus remains to be controversial. Here, we applied bisulfite sequencing in conjunction with a biological replicate strategy to investigate the DNA methylation profiling of A. flavus genome. Both the bisulfite sequencing data and the methylome comparisons with other fungi confirm that the DNA methylation level of this fungus is negligible. Further investigation into the DNA methyltransferase of Aspergillus uncovers its close relationship with RID-like enzymes as well as its divergence with the methyltransferase of species with validated DNA methylation. The lack of repeat contents of the A. flavus' genome and the high RIP-index of the small amount of remanent repeat potentially support our speculation that DNA methylation may be absent in A. flavus or that it may possess de novo DNA methylation which occurs very transiently during the obscure sexual stage of this fungal species. This work contributes to our understanding on the DNA methylation status of A. flavus, as well as reinforces our views on the DNA methylation in fungal species. In addition, our strategy of applying bisulfite sequencing to DNA methylation detection in species with low DNA methylation may serve as a reference for later scientific investigations in other hypomethylated species.
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Affiliation(s)
- Si-Yang Liu
- MOE Key Laboratory of Aquatic Product Safety, Key Laboratory of Gene Engineering of the Ministry of Education, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
- BGI-Shenzhen, Shenzhen, China
| | - Jian-Qing Lin
- MOE Key Laboratory of Aquatic Product Safety, Key Laboratory of Gene Engineering of the Ministry of Education, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | | | - Cheng-Cheng Wang
- MOE Key Laboratory of Aquatic Product Safety, Key Laboratory of Gene Engineering of the Ministry of Education, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | | | - Yan-Feng Luo
- MOE Key Laboratory of Aquatic Product Safety, Key Laboratory of Gene Engineering of the Ministry of Education, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | | | - Jian-Xiang Zhou
- MOE Key Laboratory of Aquatic Product Safety, Key Laboratory of Gene Engineering of the Ministry of Education, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | | | - Jian-Guo He
- MOE Key Laboratory of Aquatic Product Safety, Key Laboratory of Gene Engineering of the Ministry of Education, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
- * E-mail: (J-GH); (JW); (Z-MH)
| | - Jun Wang
- BGI-Shenzhen, Shenzhen, China
- * E-mail: (J-GH); (JW); (Z-MH)
| | - Zhu-Mei He
- MOE Key Laboratory of Aquatic Product Safety, Key Laboratory of Gene Engineering of the Ministry of Education, School of Life Sciences, Sun Yat-sen University, Guangzhou, China
- * E-mail: (J-GH); (JW); (Z-MH)
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Genome-wide comparative analysis of pogo-like transposable elements in different Fusarium species. J Mol Evol 2011; 73:230-43. [PMID: 22094890 DOI: 10.1007/s00239-011-9472-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Accepted: 11/07/2011] [Indexed: 10/15/2022]
Abstract
The recent availability of genome sequences of four different Fusarium species offers the opportunity to perform extensive comparative analyses, in particular of repeated sequences. In a recent work, the overall content of such sequences in the genomes of three phylogenetically related Fusarium species, F. graminearum, F. verticillioides, and F. oxysporum f. sp. lycopersici has been estimated. In this study, we present an exhaustive characterization of pogo-like elements, named Fots, in four Fusarium genomes. Overall 10 Fot and two Fot-related miniature inverted-repeat transposable element families were identified, revealing a diversification of multiple lineages of pogo-like elements, some of which accompanied by a gain of introns. This analysis also showed that such elements are present in an unusual high proportion in the genomes of F. oxysporum f. sp. lycopersici and Nectria haematococca (anamorph F. solani f. sp. pisi) in contrast with most other fungal genomes in which retroelements are the most represented. Interestingly, our analysis showed that the most numerous Fot families all contain potentially active or mobilisable copies, thus conferring a mutagenic potential of these transposable elements and consequently a role in strain adaptation and genome evolution. This role is strongly reinforced when examining their genomic distribution which is clearly biased with a high proportion (more than 80%) located on strain- or species-specific regions enriched in genes involved in pathogenicity and/or adaptation. Finally, the different reproductive characteristics of the four Fusarium species allowed us to investigate the impact of the process of repeat-induced point mutations on the expansion and diversification of Fot elements.
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Yang J, Wang L, Ji X, Feng Y, Li X, Zou C, Xu J, Ren Y, Mi Q, Wu J, Liu S, Liu Y, Huang X, Wang H, Niu X, Li J, Liang L, Luo Y, Ji K, Zhou W, Yu Z, Li G, Liu Y, Li L, Qiao M, Feng L, Zhang KQ. Genomic and proteomic analyses of the fungus Arthrobotrys oligospora provide insights into nematode-trap formation. PLoS Pathog 2011; 7:e1002179. [PMID: 21909256 PMCID: PMC3164635 DOI: 10.1371/journal.ppat.1002179] [Citation(s) in RCA: 190] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2010] [Accepted: 06/09/2011] [Indexed: 12/18/2022] Open
Abstract
Nematode-trapping fungi are "carnivorous" and attack their hosts using specialized trapping devices. The morphological development of these traps is the key indicator of their switch from saprophytic to predacious lifestyles. Here, the genome of the nematode-trapping fungus Arthrobotrys oligospora Fres. (ATCC24927) was reported. The genome contains 40.07 Mb assembled sequence with 11,479 predicted genes. Comparative analysis showed that A. oligospora shared many more genes with pathogenic fungi than with non-pathogenic fungi. Specifically, compared to several sequenced ascomycete fungi, the A. oligospora genome has a larger number of pathogenicity-related genes in the subtilisin, cellulase, cellobiohydrolase, and pectinesterase gene families. Searching against the pathogen-host interaction gene database identified 398 homologous genes involved in pathogenicity in other fungi. The analysis of repetitive sequences provided evidence for repeat-induced point mutations in A. oligospora. Proteomic and quantitative PCR (qPCR) analyses revealed that 90 genes were significantly up-regulated at the early stage of trap-formation by nematode extracts and most of these genes were involved in translation, amino acid metabolism, carbohydrate metabolism, cell wall and membrane biogenesis. Based on the combined genomic, proteomic and qPCR data, a model for the formation of nematode trapping device in this fungus was proposed. In this model, multiple fungal signal transduction pathways are activated by its nematode prey to further regulate downstream genes associated with diverse cellular processes such as energy metabolism, biosynthesis of the cell wall and adhesive proteins, cell division, glycerol accumulation and peroxisome biogenesis. This study will facilitate the identification of pathogenicity-related genes and provide a broad foundation for understanding the molecular and evolutionary mechanisms underlying fungi-nematodes interactions.
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Affiliation(s)
- Jinkui Yang
- Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education, Yunnan University, Kunming, P. R. China
| | - Lei Wang
- TEDA School of Biological Sciences and Biotechnology, Nankai University, Tianjin, P. R. China
| | - Xinglai Ji
- Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education, Yunnan University, Kunming, P. R. China
| | - Yun Feng
- TEDA School of Biological Sciences and Biotechnology, Nankai University, Tianjin, P. R. China
| | - Xiaomin Li
- TEDA School of Biological Sciences and Biotechnology, Nankai University, Tianjin, P. R. China
| | - Chenggang Zou
- Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education, Yunnan University, Kunming, P. R. China
| | - Jianping Xu
- Department of Biology, McMaster University, Hamilton, Ontario, Canada
| | - Yan Ren
- TEDA School of Biological Sciences and Biotechnology, Nankai University, Tianjin, P. R. China
| | - Qili Mi
- Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education, Yunnan University, Kunming, P. R. China
- Yunnan Academy of Tobacco Science, Kunming, P. R. China
| | - Junli Wu
- TEDA School of Biological Sciences and Biotechnology, Nankai University, Tianjin, P. R. China
| | - Shuqun Liu
- Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education, Yunnan University, Kunming, P. R. China
| | - Yu Liu
- TEDA School of Biological Sciences and Biotechnology, Nankai University, Tianjin, P. R. China
| | - Xiaowei Huang
- Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education, Yunnan University, Kunming, P. R. China
| | - Haiyan Wang
- TEDA School of Biological Sciences and Biotechnology, Nankai University, Tianjin, P. R. China
| | - Xuemei Niu
- Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education, Yunnan University, Kunming, P. R. China
| | - Juan Li
- Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education, Yunnan University, Kunming, P. R. China
| | - Lianming Liang
- Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education, Yunnan University, Kunming, P. R. China
| | - Yanlu Luo
- Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education, Yunnan University, Kunming, P. R. China
| | - Kaifang Ji
- Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education, Yunnan University, Kunming, P. R. China
| | - Wei Zhou
- Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education, Yunnan University, Kunming, P. R. China
| | - Zefen Yu
- Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education, Yunnan University, Kunming, P. R. China
| | - Guohong Li
- Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education, Yunnan University, Kunming, P. R. China
| | - Yajun Liu
- Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education, Yunnan University, Kunming, P. R. China
| | - Lei Li
- Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education, Yunnan University, Kunming, P. R. China
| | - Min Qiao
- Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education, Yunnan University, Kunming, P. R. China
| | - Lu Feng
- TEDA School of Biological Sciences and Biotechnology, Nankai University, Tianjin, P. R. China
| | - Ke-Qin Zhang
- Laboratory for Conservation and Utilization of Bio-Resources, and Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education, Yunnan University, Kunming, P. R. China
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Kubicek CP, Herrera-Estrella A, Seidl-Seiboth V, Martinez DA, Druzhinina IS, Thon M, Zeilinger S, Casas-Flores S, Horwitz BA, Mukherjee PK, Mukherjee M, Kredics L, Alcaraz LD, Aerts A, Antal Z, Atanasova L, Cervantes-Badillo MG, Challacombe J, Chertkov O, McCluskey K, Coulpier F, Deshpande N, von Döhren H, Ebbole DJ, Esquivel-Naranjo EU, Fekete E, Flipphi M, Glaser F, Gómez-Rodríguez EY, Gruber S, Han C, Henrissat B, Hermosa R, Hernández-Oñate M, Karaffa L, Kosti I, Le Crom S, Lindquist E, Lucas S, Lübeck M, Lübeck PS, Margeot A, Metz B, Misra M, Nevalainen H, Omann M, Packer N, Perrone G, Uresti-Rivera EE, Salamov A, Schmoll M, Seiboth B, Shapiro H, Sukno S, Tamayo-Ramos JA, Tisch D, Wiest A, Wilkinson HH, Zhang M, Coutinho PM, Kenerley CM, Monte E, Baker SE, Grigoriev IV. Comparative genome sequence analysis underscores mycoparasitism as the ancestral life style of Trichoderma. Genome Biol 2011; 12:R40. [PMID: 21501500 PMCID: PMC3218866 DOI: 10.1186/gb-2011-12-4-r40] [Citation(s) in RCA: 381] [Impact Index Per Article: 29.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2010] [Revised: 03/28/2011] [Accepted: 04/18/2011] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Mycoparasitism, a lifestyle where one fungus is parasitic on another fungus, has special relevance when the prey is a plant pathogen, providing a strategy for biological control of pests for plant protection. Probably, the most studied biocontrol agents are species of the genus Hypocrea/Trichoderma. RESULTS Here we report an analysis of the genome sequences of the two biocontrol species Trichoderma atroviride (teleomorph Hypocrea atroviridis) and Trichoderma virens (formerly Gliocladium virens, teleomorph Hypocrea virens), and a comparison with Trichoderma reesei (teleomorph Hypocrea jecorina). These three Trichoderma species display a remarkable conservation of gene order (78 to 96%), and a lack of active mobile elements probably due to repeat-induced point mutation. Several gene families are expanded in the two mycoparasitic species relative to T. reesei or other ascomycetes, and are overrepresented in non-syntenic genome regions. A phylogenetic analysis shows that T. reesei and T. virens are derived relative to T. atroviride. The mycoparasitism-specific genes thus arose in a common Trichoderma ancestor but were subsequently lost in T. reesei. CONCLUSIONS The data offer a better understanding of mycoparasitism, and thus enforce the development of improved biocontrol strains for efficient and environmentally friendly protection of plants.
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Affiliation(s)
- Christian P Kubicek
- Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering Vienna University of Technology, Getreidemarkt 9, 1060 Vienna, Austria
| | - Alfredo Herrera-Estrella
- Laboratorio Nacional de Genómica para la Biodiversidad, Cinvestav Campus Guanajuato, Km. 9.6 Libramiento Norte, Carretera Irapuato-León, 36821 Irapuato, Mexico
| | - Verena Seidl-Seiboth
- Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering Vienna University of Technology, Getreidemarkt 9, 1060 Vienna, Austria
| | - Diego A Martinez
- Broad Institute of MIT and Harvard, 301 Binney St, Cambridge, MA 02142, USA
| | - Irina S Druzhinina
- Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering Vienna University of Technology, Getreidemarkt 9, 1060 Vienna, Austria
| | - Michael Thon
- Centro Hispanoluso de Investigaciones Agrarias (CIALE), Department of Microbiology and Genetics, University of Salamanca, Calle Del Duero, 12, Villamayor 37185, Spain
| | - Susanne Zeilinger
- Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering Vienna University of Technology, Getreidemarkt 9, 1060 Vienna, Austria
| | - Sergio Casas-Flores
- División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa San José, No. 2055, Colonia Lomas 4a Sección, San Luis Potosí, SLP., 78216, México
| | - Benjamin A Horwitz
- Department of Biology, Technion - Israel Institute of Technology, Neve Shaanan Campus, Technion City, Haifa, 32000, Israel
| | - Prasun K Mukherjee
- Nuclear Agriculture and Biotechnology Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India
| | - Mala Mukherjee
- Department of Biology, Technion - Israel Institute of Technology, Neve Shaanan Campus, Technion City, Haifa, 32000, Israel
| | - László Kredics
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Közép fasor 52, Szeged, H-6726, Hungary
| | - Luis D Alcaraz
- Laboratorio Nacional de Genómica para la Biodiversidad, Cinvestav Campus Guanajuato, Km. 9.6 Libramiento Norte, Carretera Irapuato-León, 36821 Irapuato, Mexico
| | - Andrea Aerts
- DOE Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA 94598, USA
| | - Zsuzsanna Antal
- Department of Microbiology, Faculty of Science and Informatics, University of Szeged, Közép fasor 52, Szeged, H-6726, Hungary
| | - Lea Atanasova
- Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering Vienna University of Technology, Getreidemarkt 9, 1060 Vienna, Austria
| | - Mayte G Cervantes-Badillo
- División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa San José, No. 2055, Colonia Lomas 4a Sección, San Luis Potosí, SLP., 78216, México
| | - Jean Challacombe
- DOE Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA 94598, USA
| | - Olga Chertkov
- DOE Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA 94598, USA
| | - Kevin McCluskey
- School of Biological Sciences, University of Missouri- Kansas City, 5007 Rockhill Road, Kansas City, MO 64110, USA
| | - Fanny Coulpier
- Institut de Biologie de l'École normale supérieure (IBENS), Institut National de la Santé et de la Recherche Médicale U1024, Centre National de la Recherche Scientifique UMR8197, 46, rue d'Ulm, Paris 75005, France
| | - Nandan Deshpande
- Chemistry and Biomolecular Sciences, Macquarie University, Research Park Drive Building F7B, North Ryde, Sydney, NSW 2109, Australia
| | - Hans von Döhren
- TU Berlin, Institut für Chemie, FG Biochemie und Molekulare Biologie OE2, Franklinstr. 29, 10587 Berlin, Germany
| | - Daniel J Ebbole
- Department of Plant Pathology and Microbiology Building 0444, Nagle Street, Texas A&M University College Station, TX 77843, USA
| | - Edgardo U Esquivel-Naranjo
- Laboratorio Nacional de Genómica para la Biodiversidad, Cinvestav Campus Guanajuato, Km. 9.6 Libramiento Norte, Carretera Irapuato-León, 36821 Irapuato, Mexico
| | - Erzsébet Fekete
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, Debrecen, H-4010, Hungary
| | - Michel Flipphi
- Instituto de Agroquímica y Tecnología de Alimentos, Consejo Superior de Investigaciones Científicas, Apartado de Correos 73, Burjassot (Valencia) E-46100, Spain
| | - Fabian Glaser
- Department of Biology, Technion - Israel Institute of Technology, Neve Shaanan Campus, Technion City, Haifa, 32000, Israel
| | - Elida Y Gómez-Rodríguez
- División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa San José, No. 2055, Colonia Lomas 4a Sección, San Luis Potosí, SLP., 78216, México
| | - Sabine Gruber
- Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering Vienna University of Technology, Getreidemarkt 9, 1060 Vienna, Austria
| | - Cliff Han
- DOE Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA 94598, USA
| | - Bernard Henrissat
- Architecture et Fonction des Macromolécules Biologiques, UMR6098, CNRS, Université de la Méditerranée, Case 932, 163 Avenue de Luminy, 13288 Marseille 13288, France
| | - Rosa Hermosa
- Centro Hispanoluso de Investigaciones Agrarias (CIALE), Department of Microbiology and Genetics, University of Salamanca, Calle Del Duero, 12, Villamayor 37185, Spain
| | - Miguel Hernández-Oñate
- Laboratorio Nacional de Genómica para la Biodiversidad, Cinvestav Campus Guanajuato, Km. 9.6 Libramiento Norte, Carretera Irapuato-León, 36821 Irapuato, Mexico
| | - Levente Karaffa
- Department of Biochemical Engineering, Faculty of Science and Technology, University of Debrecen, Egyetem tér 1, Debrecen, H-4010, Hungary
| | - Idit Kosti
- Department of Biology, Technion - Israel Institute of Technology, Neve Shaanan Campus, Technion City, Haifa, 32000, Israel
| | - Stéphane Le Crom
- Institut de Biologie de l'École normale supérieure (IBENS), Institut National de la Santé et de la Recherche Médicale U1024, Centre National de la Recherche Scientifique UMR8197, 46, rue d'Ulm, Paris 75005, France
| | - Erika Lindquist
- DOE Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA 94598, USA
| | - Susan Lucas
- DOE Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA 94598, USA
| | - Mette Lübeck
- Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Lautrupvang 15, DK-2750 Ballerup, Denmark
| | - Peter S Lübeck
- Department of Biotechnology, Chemistry and Environmental Engineering, Aalborg University, Lautrupvang 15, DK-2750 Ballerup, Denmark
| | - Antoine Margeot
- Biotechnology Department, IFP Energies nouvelles, 1-4 avenue de Bois Préau, Rueil-Malmaison, 92852, France
| | - Benjamin Metz
- Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering Vienna University of Technology, Getreidemarkt 9, 1060 Vienna, Austria
| | - Monica Misra
- DOE Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA 94598, USA
| | - Helena Nevalainen
- Chemistry and Biomolecular Sciences, Macquarie University, Research Park Drive Building F7B, North Ryde, Sydney, NSW 2109, Australia
| | - Markus Omann
- Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering Vienna University of Technology, Getreidemarkt 9, 1060 Vienna, Austria
| | - Nicolle Packer
- Chemistry and Biomolecular Sciences, Macquarie University, Research Park Drive Building F7B, North Ryde, Sydney, NSW 2109, Australia
| | - Giancarlo Perrone
- Institute of Sciences of Food Production (ISPA), National Research Council (CNR), Via Amendola 122/O, 70126 Bari, Italy
| | - Edith E Uresti-Rivera
- División de Biología Molecular, Instituto Potosino de Investigación Científica y Tecnológica, Camino a la Presa San José, No. 2055, Colonia Lomas 4a Sección, San Luis Potosí, SLP., 78216, México
| | - Asaf Salamov
- DOE Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA 94598, USA
| | - Monika Schmoll
- Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering Vienna University of Technology, Getreidemarkt 9, 1060 Vienna, Austria
| | - Bernhard Seiboth
- Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering Vienna University of Technology, Getreidemarkt 9, 1060 Vienna, Austria
| | - Harris Shapiro
- DOE Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA 94598, USA
| | - Serenella Sukno
- Centro Hispanoluso de Investigaciones Agrarias (CIALE), Department of Microbiology and Genetics, University of Salamanca, Calle Del Duero, 12, Villamayor 37185, Spain
| | - Juan Antonio Tamayo-Ramos
- Wageningen University, Systems and Synthetic Biology, Fungal Systems Biology Group, Dreijenplein 10, 6703 HB Wageningen, The Netherlands
| | - Doris Tisch
- Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering Vienna University of Technology, Getreidemarkt 9, 1060 Vienna, Austria
| | - Aric Wiest
- School of Biological Sciences, University of Missouri- Kansas City, 5007 Rockhill Road, Kansas City, MO 64110, USA
| | - Heather H Wilkinson
- Department of Plant Pathology and Microbiology Building 0444, Nagle Street, Texas A&M University College Station, TX 77843, USA
| | - Michael Zhang
- DOE Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA 94598, USA
| | - Pedro M Coutinho
- Architecture et Fonction des Macromolécules Biologiques, UMR6098, CNRS, Université de la Méditerranée, Case 932, 163 Avenue de Luminy, 13288 Marseille 13288, France
| | - Charles M Kenerley
- Department of Plant Pathology and Microbiology Building 0444, Nagle Street, Texas A&M University College Station, TX 77843, USA
| | - Enrique Monte
- Centro Hispanoluso de Investigaciones Agrarias (CIALE), Department of Microbiology and Genetics, University of Salamanca, Calle Del Duero, 12, Villamayor 37185, Spain
| | - Scott E Baker
- DOE Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA 94598, USA
- Chemical and Biological Process Development Group, Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, WA 99352, USA
| | - Igor V Grigoriev
- DOE Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA 94598, USA
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Clutterbuck AJ. Genomic evidence of repeat-induced point mutation (RIP) in filamentous ascomycetes. Fungal Genet Biol 2011; 48:306-26. [PMID: 20854921 DOI: 10.1016/j.fgb.2010.09.002] [Citation(s) in RCA: 91] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2010] [Revised: 09/14/2010] [Accepted: 09/14/2010] [Indexed: 11/18/2022]
Affiliation(s)
- A John Clutterbuck
- School of Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, Scotland, UK.
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42
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Hane JK, Oliver RP. In silico reversal of repeat-induced point mutation (RIP) identifies the origins of repeat families and uncovers obscured duplicated genes. BMC Genomics 2010; 11:655. [PMID: 21106049 PMCID: PMC3017866 DOI: 10.1186/1471-2164-11-655] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2010] [Accepted: 11/24/2010] [Indexed: 12/31/2022] Open
Abstract
Background Repeat-induced point mutation (RIP) is a fungal genome defence mechanism guarding against transposon invasion. RIP mutates the sequence of repeated DNA and over time renders the affected regions unrecognisable by similarity search tools such as BLAST. Results DeRIP is a new software tool developed to predict the original sequence of a RIP-mutated region prior to the occurrence of RIP. In this study, we apply deRIP to the genome of the wheat pathogen Stagonospora nodorum SN15 and predict the origin of several previously uncharacterised classes of repetitive DNA. Conclusions Five new classes of transposon repeats and four classes of endogenous gene repeats were identified after deRIP. The deRIP process is a new tool for fungal genomics that facilitates the identification and understanding of the role and origin of fungal repetitive DNA. DeRIP is open-source and is available as part of the RIPCAL suite at http://www.sourceforge.net/projects/ripcal.
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Affiliation(s)
- James K Hane
- Faculty of Health Sciences, Murdoch University, Perth, Western Australia, 6150, Australia
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43
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Tamaru H. Confining euchromatin/heterochromatin territory: jumonji crosses the line. Genes Dev 2010; 24:1465-78. [PMID: 20634313 DOI: 10.1101/gad.1941010] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Heterochromatin is typically highly condensed, gene-poor, and transcriptionally silent, whereas euchromatin is less condensed, gene-rich, and more accessible to transcription. Besides acting as a graveyard for selfish mobile DNA repeats, heterochromatin contributes to important biological functions, such as chromosome segregation during cell division. Multiple features of heterochromatin-including the presence or absence of specific histone modifications, DNA methylation, and small RNAs-have been implicated in distinguishing heterochromatin from euchromatin in various organisms. Cells malfunction if the genome fails to restrict repressive chromatin marks within heterochromatin domains. How euchromatin and heterochromatin territories are confined remains poorly understood. Recent studies from the fission yeast Schizosaccharomyces pombe, the flowering plant Arabidopsis thaliana, and the filamentous fungus Neurospora crassa have revealed a new role for Jumonji C (JmjC) domain-containing proteins in protecting euchromatin from heterochromatin marks.
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Affiliation(s)
- Hisashi Tamaru
- Gregor Mendel Institute of Molecular Plant Biology, Austrian Academy of Sciences, Vienna, Austria.
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44
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Rountree MR, Selker EU. DNA methylation and the formation of heterochromatin in Neurospora crassa. Heredity (Edinb) 2010; 105:38-44. [PMID: 20407471 DOI: 10.1038/hdy.2010.44] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Studies of the control and function of DNA methylation in Neurospora crassa have led to a greater understanding of heterochromatin formation. DNA methylation in Neurospora is dependent on trimethylation of histone H3 lysine 9 (H3K9me3) by the histone methyltransferase, DIM-5. The linkage between these two methyl marks is facilitated by heterochromatin protein 1 (HP1), which serves as an adapter protein. HP1 binds to the H3K9me3 and recruits the DNA methyltransferase, DIM-2. Although HP1 links H3K9me3 to DNA methylation, it also serves to recruit the DNA methylation modifier complex to the edges of heterochromatin regions, where it serves to limit the spreading of the heterochromatin by countering H3K9me3.
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Affiliation(s)
- M R Rountree
- Institute of Molecular Biology, University of Oregon, Eugene, OR, USA
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45
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De novo assembly of a 40 Mb eukaryotic genome from short sequence reads: Sordaria macrospora, a model organism for fungal morphogenesis. PLoS Genet 2010; 6:e1000891. [PMID: 20386741 PMCID: PMC2851567 DOI: 10.1371/journal.pgen.1000891] [Citation(s) in RCA: 140] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2009] [Accepted: 03/02/2010] [Indexed: 01/09/2023] Open
Abstract
Filamentous fungi are of great importance in ecology, agriculture, medicine, and biotechnology. Thus, it is not surprising that genomes for more than 100 filamentous fungi have been sequenced, most of them by Sanger sequencing. While next-generation sequencing techniques have revolutionized genome resequencing, e.g. for strain comparisons, genetic mapping, or transcriptome and ChIP analyses, de novo assembly of eukaryotic genomes still presents significant hurdles, because of their large size and stretches of repetitive sequences. Filamentous fungi contain few repetitive regions in their 30-90 Mb genomes and thus are suitable candidates to test de novo genome assembly from short sequence reads. Here, we present a high-quality draft sequence of the Sordaria macrospora genome that was obtained by a combination of Illumina/Solexa and Roche/454 sequencing. Paired-end Solexa sequencing of genomic DNA to 85-fold coverage and an additional 10-fold coverage by single-end 454 sequencing resulted in approximately 4 Gb of DNA sequence. Reads were assembled to a 40 Mb draft version (N50 of 117 kb) with the Velvet assembler. Comparative analysis with Neurospora genomes increased the N50 to 498 kb. The S. macrospora genome contains even fewer repeat regions than its closest sequenced relative, Neurospora crassa. Comparison with genomes of other fungi showed that S. macrospora, a model organism for morphogenesis and meiosis, harbors duplications of several genes involved in self/nonself-recognition. Furthermore, S. macrospora contains more polyketide biosynthesis genes than N. crassa. Phylogenetic analyses suggest that some of these genes may have been acquired by horizontal gene transfer from a distantly related ascomycete group. Our study shows that, for typical filamentous fungi, de novo assembly of genomes from short sequence reads alone is feasible, that a mixture of Solexa and 454 sequencing substantially improves the assembly, and that the resulting data can be used for comparative studies to address basic questions of fungal biology.
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46
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PARP is involved in replicative aging in Neurospora crassa. Fungal Genet Biol 2010; 47:297-309. [PMID: 20045739 DOI: 10.1016/j.fgb.2009.12.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2009] [Revised: 12/10/2009] [Accepted: 12/29/2009] [Indexed: 11/22/2022]
Abstract
Modification of proteins by the addition of poly(ADP-ribose) is carried out by poly(ADP-ribose) polymerases (PARPs). PARPs have been implicated in a wide range of biological processes in eukaryotes, but no universal function has been established. A study of the Aspergillus nidulans PARP ortholog (PrpA) revealed that the protein is essential and involved in DNA repair, reminiscent of findings using mammalian systems. We found that a Neurospora PARP orthologue (NPO) is dispensable for cell survival, DNA repair and epigenetic silencing but that replicative aging of mycelia is accelerated in an npo mutant strain. We propose that PARPs may control aging as proposed for Sirtuins, which also consume NAD+ and function either as mono(ADP-ribose) transferases or protein deacetylases. PARPs may regulate aging by impacting NAD+/NAM availability, thereby influencing Sirtuin activity, or they may function in alternative NAD+-dependent or NAD+-independent aging pathways.
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47
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Liu N, Xiao ZD, Yu CH, Shao P, Liang YT, Guan DG, Yang JH, Chen CL, Qu LH, Zhou H. SnoRNAs from the filamentous fungus Neurospora crassa: structural, functional and evolutionary insights. BMC Genomics 2009; 10:515. [PMID: 19895704 PMCID: PMC2780460 DOI: 10.1186/1471-2164-10-515] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2009] [Accepted: 11/08/2009] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND SnoRNAs represent an excellent model for studying the structural and functional evolution of small non-coding RNAs involved in the post-transcriptional modification machinery for rRNAs and snRNAs in eukaryotic cells. Identification of snoRNAs from Neurospora crassa, an important model organism playing key roles in the development of modern genetics, biochemistry and molecular biology will provide insights into the evolution of snoRNA genes in the fungus kingdom. RESULTS Fifty five box C/D snoRNAs were identified and predicted to guide 71 2'-O-methylated sites including four sites on snRNAs and three sites on tRNAs. Additionally, twenty box H/ACA snoRNAs, which potentially guide 17 pseudouridylations on rRNAs, were also identified. Although not exhaustive, the study provides the first comprehensive list of two major families of snoRNAs from the filamentous fungus N. crassa. The independently transcribed strategy dominates in the expression of box H/ACA snoRNA genes, whereas most of the box C/D snoRNA genes are intron-encoded. This shows that different genomic organizations and expression modes have been adopted by the two major classes of snoRNA genes in N. crassa . Remarkably, five gene clusters represent an outstanding organization of box C/D snoRNA genes, which are well conserved among yeasts and multicellular fungi, implying their functional importance for the fungus cells. Interestingly, alternative splicing events were found in the expression of two polycistronic snoRNA gene hosts that resemble the UHG-like genes in mammals. Phylogenetic analysis further revealed that the extensive separation and recombination of two functional elements of snoRNA genes has occurred during fungus evolution. CONCLUSION This is the first genome-wide analysis of the filamentous fungus N. crassa snoRNAs that aids in understanding the differences between unicellular fungi and multicellular fungi. As compared with two yeasts, a more complex pattern of methylation guided by box C/D snoRNAs in multicellular fungus than in unicellular yeasts was revealed, indicating the high diversity of post-transcriptional modification guided by snoRNAs in the fungus kingdom.
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Affiliation(s)
- Na Liu
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510275, PR China
| | - Zhen-Dong Xiao
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510275, PR China
| | - Chun-Hong Yu
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510275, PR China
| | - Peng Shao
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510275, PR China
| | - Yin-Tong Liang
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510275, PR China
| | - Dao-Gang Guan
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510275, PR China
| | - Jian-Hua Yang
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510275, PR China
| | - Chun-Long Chen
- Centre National de la Recherche Scientifique (CNRS), UPR 2167, CGM, Gif sur Yvette, 91198, France
| | - Liang-Hu Qu
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510275, PR China
| | - Hui Zhou
- Key Laboratory of Gene Engineering of the Ministry of Education, State Key Laboratory for Biocontrol, Sun Yat-sen University, Guangzhou 510275, PR China
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48
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Relationship between phylogenetic distribution and genomic features in Neurospora crassa. PLoS One 2009; 4:e5286. [PMID: 19461939 PMCID: PMC2684829 DOI: 10.1371/journal.pone.0005286] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2008] [Accepted: 03/18/2009] [Indexed: 11/26/2022] Open
Abstract
In the post-genome era, insufficient functional annotation of predicted genes
greatly restricts the potential of mining genome data. We demonstrate that an
evolutionary approach, which is independent of functional annotation, has great
potential as a tool for genome analysis. We chose the genome of a model
filamentous fungus Neurospora crassa as an example.
Phylogenetic distribution of each predicted protein coding gene (PCG) in the
N. crassa genome was used to classify genes into six
mutually exclusive lineage specificity (LS) groups, i.e.
Eukaryote/Prokaryote-core, Dikarya-core, Ascomycota-core,
Pezizomycotina-specific, N. crassa-orphans and Others.
Functional category analysis revealed that only ∼23% of PCGs
in the two most highly lineage-specific grouping, Pezizomycotina-specific and
N. crassa-orphans, have functional annotation. In contrast,
∼76% of PCGs in the remaining four LS groups have functional
annotation. Analysis of chromosomal localization of N.
crassa-orphan PCGs and genes encoding for secreted proteins showed
enrichment in subtelomeric regions. The origin of N.
crassa-orphans is not known. We found that 11% of N.
crassa-orphans have paralogous N. crassa-orphan
genes. Of the paralogous N. crassa-orphan gene pairs,
33% were tandemly located in the genome, implying a duplication
origin of N. crassa-orphan PCGs in the past. LS grouping is
thus a useful tool to explore and understand genome organization, evolution and
gene function in fungi.
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Abstract
Telomeres and subtelomere regions have vital roles in cellular homeostasis and can facilitate niche adaptation. However, information on telomere/subtelomere structure is still limited to a small number of organisms. Prior to initiation of this project, the Neurospora crassa genome assembly contained only 3 of the 14 telomeres. The missing telomeres were identified through bioinformatic mining of raw sequence data from the genome project and from clones in new cosmid and plasmid libraries. Their chromosomal locations were assigned on the basis of paired-end read information and/or by RFLP mapping. One telomere is attached to the ribosomal repeat array. The remaining chromosome ends have atypical structures in that they lack distinct subtelomere domains or other sequence features that are associated with telomeres in other organisms. Many of the chromosome ends terminate in highly AT-rich sequences that appear to be products of repeat-induced point mutation, although most are not currently repeated sequences. Several chromosome termini in the standard Oak Ridge wild-type strain were compared to their counterparts in an exotic wild type, Mauriceville. This revealed that the sequences immediately adjacent to the telomeres are usually genome specific. Finally, despite the absence of many features typically found in the telomere regions of other organisms, the Neurospora chromosome termini still retain the dynamic nature that is characteristic of chromosome ends.
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50
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Relics of repeat-induced point mutation direct heterochromatin formation in Neurospora crassa. Genome Res 2008; 19:427-37. [PMID: 19092133 DOI: 10.1101/gr.086231.108] [Citation(s) in RCA: 113] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Both RNAi-dependent and -independent mechanisms have been implicated in the establishment of heterochromatin domains, which may be stabilized by feedback loops involving chromatin proteins and modifications of histones and DNA. Neurospora crassa sports features of heterochromatin found in higher eukaryotes, namely cytosine methylation (5mC), methylation of histone H3 lysine 9 (H3K9me), and heterochromatin protein 1 (HP1), and is a model to investigate heterochromatin establishment and maintenance. We mapped the distribution of HP1, 5mC, H3K9me3, and H3K4me2 at 100 bp resolution and explored their interplay. HP1, H3K9me3, and 5mC were extensively co-localized and defined 44 heterochromatic domains on linkage group VII, all relics of repeat-induced point mutation. Interestingly, the centromere was found in an approximately 350 kb heterochromatic domain with no detectable H3K4me2. 5mC was not found in genes, in contrast to the situation in plants and animals. H3K9me3 is required for HP1 localization and DNA methylation in N. crassa. In contrast, we found that localization of H3K9me3 was independent of 5mC or HP1 at virtually all heterochromatin regions. In addition, we observed complete restoration of DNA methylation patterns after depletion and reintroduction of the H3K9 methylation machinery. These data show that A:T-rich RIP'd DNA efficiently directs methylation of H3K9, which in turn, directs methylation of associated cytosines.
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