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Özer H, Wasser D, Sandner L, Soppa J. Intermolecular Gene Conversion for the Equalization of Genome Copies in the Polyploid Haloarchaeon Haloferax volcanii: Identification of Important Proteins. Genes (Basel) 2024; 15:861. [PMID: 39062640 PMCID: PMC11276520 DOI: 10.3390/genes15070861] [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: 05/10/2024] [Revised: 06/18/2024] [Accepted: 06/20/2024] [Indexed: 07/28/2024] Open
Abstract
The model haloarchaeon Haloferax volcanii is polyploid with about 20 copies of its major chromosome. Recently it has been described that highly efficient intermolecular gene conversion operates in H. volcanii to equalize the chromosomal copies. In the current study, 24 genes were selected that encode proteins with orthologs involved in gene conversion or homologous recombination in archaea, bacteria, or eukaryotes. Single gene deletion strains of 22 genes and a control gene were constructed in two parent strains for a gene conversion assay; only radA and radB were shown to be essential. Protoplast fusions were used to generate strains that were heterozygous for the gene HVO_2528, encoding an enzyme for carotinoid biosynthesis. It was revealed that a lack of six of the proteins did not influence the efficiency of gene conversion, while sixteen mutants had severe gene conversion defects. Notably, lack of paralogous proteins of gene families had very different effects, e.g., mutant Δrad25b had no phenotype, while mutants Δrad25a, Δrad25c, and Δrad25d were highly compromised. Generation of a quadruple rad25 and a triple sph deletion strain also indicated that the paralogs have different functions, in contrast to sph2 and sph4, which cannot be deleted simultaneously. There was no correlation between the severity of the phenotypes and the respective transcript levels under non-stressed conditions, indicating that gene expression has to be induced at the onset of gene conversion. Phylogenetic trees of the protein families Rad3/25, MutL/S, and Sph/SMC/Rad50 were generated to unravel the history of the paralogous proteins of H. volcanii. Taken together, unselected intermolecular gene conversion in H. volcanii involves at least 16 different proteins, the molecular roles of which can be studied in detail in future projects.
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Affiliation(s)
| | | | | | - Jörg Soppa
- Biocentre, Institute for Molecular Biosciences, Goethe University, Max-von-Laue-Str. 9, D-60439 Frankfurt, Germany; (H.Ö.); (D.W.); (L.S.)
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2
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Tang J, Zhang L, Su J, Ye Q, Li Y, Liu D, Cui H, Zhang Y, Ye Z. Insights into Fungal Mitochondrial Genomes and Inheritance Based on Current Findings from Yeast-like Fungi. J Fungi (Basel) 2024; 10:441. [PMID: 39057326 PMCID: PMC11277600 DOI: 10.3390/jof10070441] [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: 04/17/2024] [Revised: 06/19/2024] [Accepted: 06/20/2024] [Indexed: 07/28/2024] Open
Abstract
The primary functions of mitochondria are to produce energy and participate in the apoptosis of cells, with them being highly conserved among eukaryotes. However, the composition of mitochondrial genomes, mitochondrial DNA (mtDNA) replication, and mitochondrial inheritance varies significantly among animals, plants, and fungi. Especially in fungi, there exists a rich diversity of mitochondrial genomes, as well as various replication and inheritance mechanisms. Therefore, a comprehensive understanding of fungal mitochondria is crucial for unraveling the evolutionary history of mitochondria in eukaryotes. In this review, we have organized existing reports to systematically describe and summarize the composition of yeast-like fungal mitochondrial genomes from three perspectives: mitochondrial genome structure, encoded genes, and mobile elements. We have also provided a systematic overview of the mechanisms in mtDNA replication and mitochondrial inheritance during bisexual mating. Additionally, we have discussed and proposed open questions that require further investigation for clarification.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Zihong Ye
- Zhejiang Provincial Key Laboratory of Biometrology and Inspection & Quarantine, College of Life Sciences, China Jiliang University, Hangzhou 310018, China; (J.T.)
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Wolters JF, LaBella AL, Opulente DA, Rokas A, Hittinger CT. Mitochondrial genome diversity across the subphylum Saccharomycotina. Front Microbiol 2023; 14:1268944. [PMID: 38075892 PMCID: PMC10701893 DOI: 10.3389/fmicb.2023.1268944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 10/31/2023] [Indexed: 12/20/2023] Open
Abstract
Introduction Eukaryotic life depends on the functional elements encoded by both the nuclear genome and organellar genomes, such as those contained within the mitochondria. The content, size, and structure of the mitochondrial genome varies across organisms with potentially large implications for phenotypic variance and resulting evolutionary trajectories. Among yeasts in the subphylum Saccharomycotina, extensive differences have been observed in various species relative to the model yeast Saccharomyces cerevisiae, but mitochondrial genome sampling across many groups has been scarce, even as hundreds of nuclear genomes have become available. Methods By extracting mitochondrial assemblies from existing short-read genome sequence datasets, we have greatly expanded both the number of available genomes and the coverage across sparsely sampled clades. Results Comparison of 353 yeast mitochondrial genomes revealed that, while size and GC content were fairly consistent across species, those in the genera Metschnikowia and Saccharomyces trended larger, while several species in the order Saccharomycetales, which includes S. cerevisiae, exhibited lower GC content. Extreme examples for both size and GC content were scattered throughout the subphylum. All mitochondrial genomes shared a core set of protein-coding genes for Complexes III, IV, and V, but they varied in the presence or absence of mitochondrially-encoded canonical Complex I genes. We traced the loss of Complex I genes to a major event in the ancestor of the orders Saccharomycetales and Saccharomycodales, but we also observed several independent losses in the orders Phaffomycetales, Pichiales, and Dipodascales. In contrast to prior hypotheses based on smaller-scale datasets, comparison of evolutionary rates in protein-coding genes showed no bias towards elevated rates among aerobically fermenting (Crabtree/Warburg-positive) yeasts. Mitochondrial introns were widely distributed, but they were highly enriched in some groups. The majority of mitochondrial introns were poorly conserved within groups, but several were shared within groups, between groups, and even across taxonomic orders, which is consistent with horizontal gene transfer, likely involving homing endonucleases acting as selfish elements. Discussion As the number of available fungal nuclear genomes continues to expand, the methods described here to retrieve mitochondrial genome sequences from these datasets will prove invaluable to ensuring that studies of fungal mitochondrial genomes keep pace with their nuclear counterparts.
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Affiliation(s)
- John F. Wolters
- Laboratory of Genetics, DOE Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, Center for Genomic Science Innovation, J. F. Crow Institute for the Study of Evolution, University of Wisconsin-Madison, Madison, WI, United States
| | - Abigail L. LaBella
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte, NC, United States
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, United States
| | - Dana A. Opulente
- Laboratory of Genetics, DOE Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, Center for Genomic Science Innovation, J. F. Crow Institute for the Study of Evolution, University of Wisconsin-Madison, Madison, WI, United States
- Biology Department, Villanova University, Villanova, PA, United States
| | - Antonis Rokas
- Department of Biological Sciences, Vanderbilt University, Nashville, TN, United States
| | - Chris Todd Hittinger
- Laboratory of Genetics, DOE Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, Center for Genomic Science Innovation, J. F. Crow Institute for the Study of Evolution, University of Wisconsin-Madison, Madison, WI, United States
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4
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Mukhopadhyay J, Wai A, Hausner G. The mitogenomes of Leptographium aureum, Leptographium sp., and Grosmannia fruticeta: expansion by introns. Front Microbiol 2023; 14:1240407. [PMID: 37637121 PMCID: PMC10448965 DOI: 10.3389/fmicb.2023.1240407] [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: 06/15/2023] [Accepted: 07/26/2023] [Indexed: 08/29/2023] Open
Abstract
Introduction Many members of the Ophiostomatales are of economic importance as they are bark-beetle associates and causative agents for blue stain on timber and in some instances contribute towards tree mortality. The taxonomy of these fungi has been challenging due to the convergent evolution of many traits associated with insect dispersal and a limited number of morphological characters that happen to be highly pleomorphic. This study examines the mitochondrial genomes for three members of Leptographium sensu lato [Leptographium aureum (also known as Grosmannia aurea), Grosmannia fruticeta (also known as Leptographium fruticetum), and Leptographium sp. WIN(M)1376)]. Methods Illumina sequencing combined with gene and intron annotations and phylogenetic analysis were performed. Results Sequence analysis showed that gene content and gene synteny are conserved but mitochondrial genome sizes were variable: G. fruticeta at 63,821 bp, Leptographium sp. WIN(M)1376 at 81,823 bp and L. aureum at 104,547 bp. The variation in size is due to the number of introns and intron-associated open reading frames. Phylogenetic analysis of currently available mitochondrial genomes for members of the Ophiostomatales supports currently accepted generic arrangements within this order and specifically supports the separation of members with Leptographium-like conidiophores into two genera, with L. aureum grouping with Leptographium and G. fruticeta aligning with Grosmannia. Discussion Mitochondrial genomes are promising sequences for resolving evolutionary relationships within the Ophiostomatales.
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Affiliation(s)
| | | | - Georg Hausner
- Department of Microbiology, University of Manitoba, Winnipeg, MB, Canada
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5
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Wolters JF, LaBella AL, Opulente DA, Rokas A, Hittinger CT. Mitochondrial Genome Diversity across the Subphylum Saccharomycotina. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.28.551029. [PMID: 37577532 PMCID: PMC10418067 DOI: 10.1101/2023.07.28.551029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/15/2023]
Abstract
Eukaryotic life depends on the functional elements encoded by both the nuclear genome and organellar genomes, such as those contained within the mitochondria. The content, size, and structure of the mitochondrial genome varies across organisms with potentially large implications for phenotypic variance and resulting evolutionary trajectories. Among yeasts in the subphylum Saccharomycotina, extensive differences have been observed in various species relative to the model yeast Saccharomyces cerevisiae, but mitochondrial genome sampling across many groups has been scarce, even as hundreds of nuclear genomes have become available. By extracting mitochondrial assemblies from existing short-read genome sequence datasets, we have greatly expanded both the number of available genomes and the coverage across sparsely sampled clades. Comparison of 353 yeast mitochondrial genomes revealed that, while size and GC content were fairly consistent across species, those in the genera Metschnikowia and Saccharomyces trended larger, while several species in the order Saccharomycetales, which includes S. cerevisiae, exhibited lower GC content. Extreme examples for both size and GC content were scattered throughout the subphylum. All mitochondrial genomes shared a core set of protein-coding genes for Complexes III, IV, and V, but they varied in the presence or absence of mitochondrially-encoded canonical Complex I genes. We traced the loss of Complex I genes to a major event in the ancestor of the orders Saccharomycetales and Saccharomycodales, but we also observed several independent losses in the orders Phaffomycetales, Pichiales, and Dipodascales. In contrast to prior hypotheses based on smaller-scale datasets, comparison of evolutionary rates in protein-coding genes showed no bias towards elevated rates among aerobically fermenting (Crabtree/Warburg-positive) yeasts. Mitochondrial introns were widely distributed, but they were highly enriched in some groups. The majority of mitochondrial introns were poorly conserved within groups, but several were shared within groups, between groups, and even across taxonomic orders, which is consistent with horizontal gene transfer, likely involving homing endonucleases acting as selfish elements. As the number of available fungal nuclear genomes continues to expand, the methods described here to retrieve mitochondrial genome sequences from these datasets will prove invaluable to ensuring that studies of fungal mitochondrial genomes keep pace with their nuclear counterparts.
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Affiliation(s)
- John F. Wolters
- Laboratory of Genetics, DOE Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, Center for Genomic Science Innovation, J. F. Crow Institute for the Study of Evolution, University of Wisconsin-Madison, Madison, WI, 53726, USA
| | - Abigail L. LaBella
- Department of Bioinformatics and Genomics, University of North Carolina at Charlotte, Charlotte NC, 28223, USA
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA; Evolutionary Studies Initiative, Vanderbilt University, Nashville, TN 37235, USA
| | - Dana A. Opulente
- Laboratory of Genetics, DOE Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, Center for Genomic Science Innovation, J. F. Crow Institute for the Study of Evolution, University of Wisconsin-Madison, Madison, WI, 53726, USA
- Biology Department Villanova University, Villanova, PA 19085, USA
| | - Antonis Rokas
- Department of Biological Sciences, Vanderbilt University, Nashville, TN 37235, USA; Evolutionary Studies Initiative, Vanderbilt University, Nashville, TN 37235, USA
| | - Chris Todd Hittinger
- Laboratory of Genetics, DOE Great Lakes Bioenergy Research Center, Wisconsin Energy Institute, Center for Genomic Science Innovation, J. F. Crow Institute for the Study of Evolution, University of Wisconsin-Madison, Madison, WI, 53726, USA
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6
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Gonçalves P, Gonçalves C. Horizontal gene transfer in yeasts. Curr Opin Genet Dev 2022; 76:101950. [PMID: 35841879 DOI: 10.1016/j.gde.2022.101950] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 06/01/2022] [Accepted: 06/12/2022] [Indexed: 11/29/2022]
Abstract
Horizontal gene transfer (HGT), defined as the exchange of genetic material other than from parent to progeny, is very common in bacteria and appears to constitute the most important mechanism contributing to enlarge a species gene pool. However, in eukaryotes, HGT is certainly much less common and some early insufficiently consubstantiated cases involving bacterial donors led some to consider that it was unlikely to occur in eukaryotes outside the host/endosymbiont relationship. More recently, plenty of reports of interdomain HGT have seen the light based on the strictest criteria, many concerning filamentous fungi and yeasts. Here, we attempt to summarize the most prominent instances of HGT reported in yeasts as well as what we have been able to learn so far concerning frequency and distribution, mechanisms, barriers, function of horizontally acquired genes, and the role of HGT in domestication.
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Affiliation(s)
- Paula Gonçalves
- Associate Laboratory i4HB - Institute for Health and Bioeconomy, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal; UCIBIO - Applied Molecular Biosciences Unit, Department of Life Sciences, NOVA School of Science and Technology, Universidade NOVA de Lisboa, 2829-516 Caparica, Portugal.
| | - Carla Gonçalves
- Vanderbilt University, Department of Biological Sciences, VU Station B #35-1634, Nashville, TN 37235, United States of America; Evolutionary Studies Initiative, Vanderbilt University, VU Station B #35-1634, Nashville, TN 37235, United States of America. https://twitter.com/@ciggoncalves
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Mukhopadhyay J, Wai A, Hutchison LJ, Hausner G. The mitogenome of Urnula craterium. Can J Microbiol 2022; 68:561-568. [PMID: 35623096 DOI: 10.1139/cjm-2022-0012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Urnula craterium (Schwein.) Fr. (1851) has been reported from North America, Europe, and Asia, and can be a pathogen on various hardwood species. In this study we investigated the mitochondrial genome of U. craterium. The biology and taxonomy of this fungus is poorly studied and there are no mitogenomes currently available for any member of the Sarcosomataceae (Order Pezizales). The complete mitogenome of U. craterium comprises 43 967 bps and encodes 14 protein-coding genes, a complete set of tRNAs and rRNA genes. A novel feature of the mitogenome is the presence of a single subunit DNA polymerase coding region that is typically associated with linear invertron-type plasmids. The mitogenome may offer insights into the evolution of mitogenomes among members of the Pezizales with regards to gene content and order, mobile elements, and genome sizes.
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Affiliation(s)
| | - Alvan Wai
- University of Manitoba, 8664, Winnipeg, Canada;
| | - Leonard J Hutchison
- Lakehead University Faculty of Natural Resources Management, 157776, Thunder Bay, Ontario, Canada;
| | - Georg Hausner
- University of Manitoba, 8664, Buller Building 213, Winnipeg, Manitoba, Canada;
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8
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Hao W. From Genome Variation to Molecular Mechanisms: What we Have Learned From Yeast Mitochondrial Genomes? Front Microbiol 2022; 13:806575. [PMID: 35126340 PMCID: PMC8811140 DOI: 10.3389/fmicb.2022.806575] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 01/03/2022] [Indexed: 11/26/2022] Open
Abstract
Analysis of genome variation provides insights into mechanisms in genome evolution. This is increasingly appreciated with the rapid growth of genomic data. Mitochondrial genomes (mitogenomes) are well known to vary substantially in many genomic aspects, such as genome size, sequence context, nucleotide base composition and substitution rate. Such substantial variation makes mitogenomes an excellent model system to study the mechanisms dictating mitogenome variation. Recent sequencing efforts have not only covered a rich number of yeast species but also generated genomes from abundant strains within the same species. The rich yeast genomic data have enabled detailed investigation from genome variation into molecular mechanisms in genome evolution. This mini-review highlights some recent progresses in yeast mitogenome studies.
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Ali SS, Amoako-Attah I, Shao J, Kumi-Asare E, Meinhardt LW, Bailey BA. Mitochondrial Genomics of Six Cacao Pathogens From the Basidiomycete Family Marasmiaceae. Front Microbiol 2021; 12:752094. [PMID: 34777305 PMCID: PMC8581569 DOI: 10.3389/fmicb.2021.752094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 10/01/2021] [Indexed: 11/23/2022] Open
Abstract
Thread blight disease has recently been described as an emerging disease on cacao (Theobroma cacao) in Ghana. In Ghana, thread blight disease is caused by multiple species of the Marasmiaceae family: Marasmius tenuissimus, M. crinis-equi, M. palmivorus, and Marasmiellus scandens. Interestingly, two additional members of the Marasmiaceae; Moniliophthora roreri (frosty pod rot) and Moniliophthora perniciosa (witches’ broom disease), are major pathogens of cacao in the Western hemisphere. It is important to accurately characterize the genetic relationships among these economically important species in support of their disease management. We used data from Illumina NGS-based genome sequencing efforts to study the mitochondrial genomes (mitogenomes) of the four cacao thread blight associated pathogens from Ghana and compared them with published mitogenomes of Mon. roreri and Mon. perniciosa. There is a remarkable interspecies variation in mitogenome size within the six cacao-associated Marasmiaceae species, ranging from 43,121 to 109,103 bp. The differences in genome lengths are primarily due to the number and lengths of introns, differences in intergenic space, and differences in the size and numbers of unidentified ORFs (uORF). Among seven M. tenuissimus mitogenomes sequenced, there is variation in size and sequence pointing to divergent evolution patterns within the species. The intronic regions show a high degree of sequence variation compared to the conserved sequences of the 14 core genes. The intronic ORFs identified, regardless of species, encode GIY-YIG or LAGLIDADG domain-containing homing endonuclease genes. Phylogenetic relationships using the 14 core proteins largely mimic the phylogenetic relationships observed in gene order patterns, grouping M. tenuissimus with M. crinis-equi, and M. palmivorus with Mon. roreri and Mon. perniciosa, leaving Mar. scandens as an outlier. The results from this study provide evidence of independent expansion/contraction events and sequence diversification in each species and establish a foundation for further exploration of the evolutionary trajectory of the fungi in Marasmiaceae family.
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Affiliation(s)
- Shahin S Ali
- Sustainable Perennial Crops Laboratory, U. S. Department of Agriculture (USDA)/Agricultural Research Service (ARS), Beltsville Agricultural Research Center-West, Beltsville, MD, United States.,Department of Viticulture and Enology, University of California, Davis, Davis, CA, United States
| | | | - Jonathan Shao
- U. S. Department of Agriculture (USDA)/Agricultural Research Service (ARS), Beltsville, MD, United States
| | | | - Lyndel W Meinhardt
- Sustainable Perennial Crops Laboratory, U. S. Department of Agriculture (USDA)/Agricultural Research Service (ARS), Beltsville Agricultural Research Center-West, Beltsville, MD, United States
| | - Bryan A Bailey
- Sustainable Perennial Crops Laboratory, U. S. Department of Agriculture (USDA)/Agricultural Research Service (ARS), Beltsville Agricultural Research Center-West, Beltsville, MD, United States
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10
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Mukhopadhyay J, Hausner G. Organellar Introns in Fungi, Algae, and Plants. Cells 2021; 10:cells10082001. [PMID: 34440770 PMCID: PMC8393795 DOI: 10.3390/cells10082001] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 07/31/2021] [Accepted: 08/05/2021] [Indexed: 12/16/2022] Open
Abstract
Introns are ubiquitous in eukaryotic genomes and have long been considered as ‘junk RNA’ but the huge energy expenditure in their transcription, removal, and degradation indicate that they may have functional significance and can offer evolutionary advantages. In fungi, plants and algae introns make a significant contribution to the size of the organellar genomes. Organellar introns are classified as catalytic self-splicing introns that can be categorized as either Group I or Group II introns. There are some biases, with Group I introns being more frequently encountered in fungal mitochondrial genomes, whereas among plants Group II introns dominate within the mitochondrial and chloroplast genomes. Organellar introns can encode a variety of proteins, such as maturases, homing endonucleases, reverse transcriptases, and, in some cases, ribosomal proteins, along with other novel open reading frames. Although organellar introns are viewed to be ribozymes, they do interact with various intron- or nuclear genome-encoded protein factors that assist in the intron RNA to fold into competent splicing structures, or facilitate the turn-over of intron RNAs to prevent reverse splicing. Organellar introns are also known to be involved in non-canonical splicing, such as backsplicing and trans-splicing which can result in novel splicing products or, in some instances, compensate for the fragmentation of genes by recombination events. In organellar genomes, Group I and II introns may exist in nested intronic arrangements, such as introns within introns, referred to as twintrons, where splicing of the external intron may be dependent on splicing of the internal intron. These nested or complex introns, with two or three-component intron modules, are being explored as platforms for alternative splicing and their possible function as molecular switches for modulating gene expression which could be potentially applied towards heterologous gene expression. This review explores recent findings on organellar Group I and II introns, focusing on splicing and mobility mechanisms aided by associated intron/nuclear encoded proteins and their potential roles in organellar gene expression and cross talk between nuclear and organellar genomes. Potential application for these types of elements in biotechnology are also discussed.
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MESH Headings
- Evolution, Molecular
- Gene Expression Regulation, Fungal
- Gene Expression Regulation, Plant
- Genome, Fungal
- Genome, Plant
- Introns
- Organelles/genetics
- Organelles/metabolism
- RNA Splicing
- RNA Stability
- RNA, Algal/genetics
- RNA, Algal/metabolism
- RNA, Fungal/genetics
- RNA, Fungal/metabolism
- RNA, Plant/genetics
- RNA, Plant/metabolism
- RNA, Untranslated/genetics
- RNA, Untranslated/metabolism
- Transcription, Genetic
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11
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Bágeľová Poláková S, Lichtner Ž, Szemes T, Smolejová M, Sulo P. Mitochondrial DNA duplication, recombination, and introgression during interspecific hybridization. Sci Rep 2021; 11:12726. [PMID: 34135414 PMCID: PMC8209160 DOI: 10.1038/s41598-021-92125-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 06/03/2021] [Indexed: 02/05/2023] Open
Abstract
mtDNA recombination events in yeasts are known, but altered mitochondrial genomes were not completed. Therefore, we analyzed recombined mtDNAs in six Saccharomyces cerevisiae × Saccharomyces paradoxus hybrids in detail. Assembled molecules contain mostly segments with variable length introgressed to other mtDNA. All recombination sites are in the vicinity of the mobile elements, introns in cox1, cob genes and free standing ORF1, ORF4. The transplaced regions involve co-converted proximal exon regions. Thus, these selfish elements are beneficial to the host if the mother molecule is challenged with another molecule for transmission to the progeny. They trigger mtDNA recombination ensuring the transfer of adjacent regions, into the progeny of recombinant molecules. The recombination of the large segments may result in mitotically stable duplication of several genes.
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Affiliation(s)
- Silvia Bágeľová Poláková
- grid.7634.60000000109409708Department of Biochemistry, Faculty of Natural Sciences, Comenius University, Ilkovičova 6, Bratislava, 842 15 Slovakia ,grid.419303.c0000 0001 2180 9405Present Address: Department of Membrane Biochemistry, Centre of Biosciences, Slovak Academy of Sciences, Bratislava, 84005 Slovakia
| | - Žaneta Lichtner
- grid.7634.60000000109409708Department of Biochemistry, Faculty of Natural Sciences, Comenius University, Ilkovičova 6, Bratislava, 842 15 Slovakia
| | - Tomáš Szemes
- grid.7634.60000000109409708Comenius University Science Park, Bratislava, 841 04 Slovakia ,grid.7634.60000000109409708Department of Molecular Biology, Faculty of Natural Sciences, Comenius University, Bratislava, 842 15 Slovakia ,Geneton s.r.o., Galvaniho 7, Bratislava, 821 04 Slovakia
| | - Martina Smolejová
- grid.7634.60000000109409708Department of Biochemistry, Faculty of Natural Sciences, Comenius University, Ilkovičova 6, Bratislava, 842 15 Slovakia
| | - Pavol Sulo
- grid.7634.60000000109409708Department of Biochemistry, Faculty of Natural Sciences, Comenius University, Ilkovičova 6, Bratislava, 842 15 Slovakia
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12
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Mayers CG, Harrington TC, Wai A, Hausner G. Recent and Ongoing Horizontal Transfer of Mitochondrial Introns Between Two Fungal Tree Pathogens. Front Microbiol 2021; 12:656609. [PMID: 34149643 PMCID: PMC8208691 DOI: 10.3389/fmicb.2021.656609] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 04/09/2021] [Indexed: 11/23/2022] Open
Abstract
Two recently introduced fungal plant pathogens (Ceratocystis lukuohia and Ceratocystis huliohia) are responsible for Rapid ‘ōhi‘a Death (ROD) in Hawai‘i. Despite being sexually incompatible, the two pathogens often co-occur in diseased ‘ōhi‘a sapwood, where genetic interaction is possible. We sequenced and annotated 33 mitochondrial genomes of the two pathogens and related species, and investigated 35 total Ceratocystis mitogenomes. Ten mtDNA regions [one group I intron, seven group II introns, and two autonomous homing endonuclease (HE) genes] were heterogeneously present in C. lukuohia mitogenomes, which were otherwise identical. Molecular surveys with specific primers showed that the 10 regions had uneven geographic distribution amongst populations of C. lukuohia. Conversely, identical orthologs of each region were present in every studied isolate of C. huliohia regardless of geographical origin. Close relatives of C. lukuohia lacked or, rarely, had few and dissimilar orthologs of the 10 regions, whereas most relatives of C. huliohia had identical or nearly identical orthologs. Each region included or worked in tandem with HE genes or reverse transcriptase/maturases that could facilitate interspecific horizontal transfers from intron-minus to intron-plus alleles. These results suggest that the 10 regions originated in C. huliohia and are actively moving to populations of C. lukuohia, perhaps through transient cytoplasmic contact of hyphal tips (anastomosis) in the wound surface of ‘ōhi‘a trees. Such contact would allow for the transfer of mitochondria followed by mitochondrial fusion or cytoplasmic exchange of intron intermediaries, which suggests that further genomic interaction may also exist between the two pathogens.
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Affiliation(s)
- Chase G Mayers
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, United States
| | - Thomas C Harrington
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, United States
| | - Alvan Wai
- Department of Microbiology, University of Manitoba, Winnipeg, MB, Canada
| | - Georg Hausner
- Department of Microbiology, University of Manitoba, Winnipeg, MB, Canada
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13
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A functional bacteria-derived restriction modification system in the mitochondrion of a heterotrophic protist. PLoS Biol 2021; 19:e3001126. [PMID: 33891594 PMCID: PMC8099122 DOI: 10.1371/journal.pbio.3001126] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 05/05/2021] [Accepted: 03/23/2021] [Indexed: 01/04/2023] Open
Abstract
The overarching trend in mitochondrial genome evolution is functional streamlining coupled with gene loss. Therefore, gene acquisition by mitochondria is considered to be exceedingly rare. Selfish elements in the form of self-splicing introns occur in many organellar genomes, but the wider diversity of selfish elements, and how they persist in the DNA of organelles, has not been explored. In the mitochondrial genome of a marine heterotrophic katablepharid protist, we identify a functional type II restriction modification (RM) system originating from a horizontal gene transfer (HGT) event involving bacteria related to flavobacteria. This RM system consists of an HpaII-like endonuclease and a cognate cytosine methyltransferase (CM). We demonstrate that these proteins are functional by heterologous expression in both bacterial and eukaryotic cells. These results suggest that a mitochondrion-encoded RM system can function as a toxin-antitoxin selfish element, and that such elements could be co-opted by eukaryotic genomes to drive biased organellar inheritance.
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14
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de Almeida JR, Riaño Pachón DM, Franceschini LM, dos Santos IB, Ferrarezi JA, de Andrade PAM, Monteiro-Vitorello CB, Labate CA, Quecine MC. Revealing the high variability on nonconserved core and mobile elements of Austropuccinia psidii and other rust mitochondrial genomes. PLoS One 2021; 16:e0248054. [PMID: 33705433 PMCID: PMC7951889 DOI: 10.1371/journal.pone.0248054] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 02/18/2021] [Indexed: 01/12/2023] Open
Abstract
Mitochondrial genomes are highly conserved in many fungal groups, and they can help characterize the phylogenetic relationships and evolutionary biology of plant pathogenic fungi. Rust fungi are among the most devastating diseases for economically important crops around the world. Here, we report the complete sequence and annotation of the mitochondrial genome of Austropuccinia psidii (syn. Puccinia psidii), the causal agent of myrtle rust. We performed a phylogenomic analysis including the complete mitochondrial sequences from other rust fungi. The genome composed of 93.299 bp has 73 predicted genes, 33 of which encoded nonconserved proteins (ncORFs), representing almost 45% of all predicted genes. A. psidii mtDNA is one of the largest rust mtDNA sequenced to date, most likely due to the abundance of ncORFs. Among them, 33% were within intronic regions of diverse intron groups. Mobile genetic elements invading intron sequences may have played significant roles in size but not shaping of the rust mitochondrial genome structure. The mtDNAs from rust fungi are highly syntenic. Phylogenetic inferences with 14 concatenated mitochondrial proteins encoded by the core genes placed A. psidii according to phylogenetic analysis based on 18S rDNA. Interestingly, cox1, the gene with the greatest number of introns, provided phylogenies not congruent with the core set. For the first time, we identified the proteins encoded by three A. psidii ncORFs using proteomics analyses. Also, the orf208 encoded a transmembrane protein repressed during in vitro morphogenesis. To the best of our knowledge, we presented the first report of a complete mtDNA sequence of a member of the family Sphaerophragmiacea.
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Affiliation(s)
- Jaqueline Raquel de Almeida
- Department of Genetics, “Luiz de Queiroz” College of Agriculture (ESALQ), University of São Paulo, Piracicaba, São Paulo, Brazil
| | | | - Livia Maria Franceschini
- Department of Genetics, “Luiz de Queiroz” College of Agriculture (ESALQ), University of São Paulo, Piracicaba, São Paulo, Brazil
| | - Isaneli Batista dos Santos
- Department of Genetics, “Luiz de Queiroz” College of Agriculture (ESALQ), University of São Paulo, Piracicaba, São Paulo, Brazil
| | - Jessica Aparecida Ferrarezi
- Department of Genetics, “Luiz de Queiroz” College of Agriculture (ESALQ), University of São Paulo, Piracicaba, São Paulo, Brazil
| | - Pedro Avelino Maia de Andrade
- Department of Genetics, “Luiz de Queiroz” College of Agriculture (ESALQ), University of São Paulo, Piracicaba, São Paulo, Brazil
| | | | - Carlos Alberto Labate
- Department of Genetics, “Luiz de Queiroz” College of Agriculture (ESALQ), University of São Paulo, Piracicaba, São Paulo, Brazil
| | - Maria Carolina Quecine
- Department of Genetics, “Luiz de Queiroz” College of Agriculture (ESALQ), University of São Paulo, Piracicaba, São Paulo, Brazil
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15
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Wai A, Hausner G. The mitochondrial genome of Ophiostoma himal-ulmi and comparison with other fungi causing Dutch elm disease. Can J Microbiol 2021; 67:584-598. [PMID: 33566742 DOI: 10.1139/cjm-2020-0589] [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] [Indexed: 01/15/2023]
Abstract
The mitochondrial genome of Ophiostoma himal-ulmi, a species endemic to the Western Himalayas and one of the fungi that cause Dutch elm disease, has been sequenced and characterized. The mitochondrial genome was compared with other available genomes for members of the Ophiostomatales, including other agents of Dutch elm disease (Ophiostoma ulmi, Ophiostoma novo-ulmi subspecies novo-ulmi, and Ophiostoma novo-ulmi subspecies americana), and it was observed that gene synteny is highly conserved, and variability among members of the fungi that cause Dutch-elm disease is primarily due to the number of intron insertions. Among the fungi that cause Dutch elm disease that we examined, O. himal-ulmi has the largest mitochondrial genomes (ranging from 94 934 to 111 712 bp), owing to the expansion of the number of introns.
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Affiliation(s)
- Alvan Wai
- Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.,Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Georg Hausner
- Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.,Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
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16
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Zubaer A, Wai A, Patel N, Perillo J, Hausner G. The Mitogenomes of Ophiostoma minus and Ophiostoma piliferum and Comparisons With Other Members of the Ophiostomatales. Front Microbiol 2021; 12:618649. [PMID: 33643245 PMCID: PMC7902536 DOI: 10.3389/fmicb.2021.618649] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Accepted: 01/04/2021] [Indexed: 12/23/2022] Open
Abstract
Fungi assigned to the Ophiostomatales are of economic concern as many are blue-stain fungi and some are plant pathogens. The mitogenomes of two blue-stain fungi, Ophiostoma minus and Ophiostoma piliferum, were sequenced and compared with currently available mitogenomes for other members of the Ophiostomatales. Species representing various genera within the Ophiostomatales have been examined for gene content, gene order, phylogenetic relationships, and the distribution of mobile elements. Gene synteny is conserved among the Ophiostomatales but some members were missing the atp9 gene. A genome wide intron landscape has been prepared to demonstrate the distribution of the mobile genetic elements (group I and II introns and homing endonucleases) and to provide insight into the evolutionary dynamics of introns among members of this group of fungi. Examples of complex introns or nested introns composed of two or three intron modules have been observed in some species. The size variation among the mitogenomes (from 23.7 kb to about 150 kb) is mostly due to the presence and absence of introns. Members of the genus Sporothrix sensu stricto appear to have the smallest mitogenomes due to loss of introns. The taxonomy of the Ophiostomatales has recently undergone considerable revisions; however, some lineages remain unresolved. The data showed that genera such as Raffaelea appear to be polyphyletic and the separation of Sporothrix sensu stricto from Ophiostoma is justified.
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Affiliation(s)
- Abdullah Zubaer
- Department of Microbiology, University of Manitoba, Winnipeg, MB, Canada
| | - Alvan Wai
- Department of Microbiology, University of Manitoba, Winnipeg, MB, Canada
| | - Nikita Patel
- Department of Microbiology, University of Manitoba, Winnipeg, MB, Canada
| | - Jordan Perillo
- Department of Microbiology, University of Manitoba, Winnipeg, MB, Canada
| | - Georg Hausner
- Department of Microbiology, University of Manitoba, Winnipeg, MB, Canada
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17
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Nguyen DT, Wu B, Xiao S, Hao W. Evolution of a Record-Setting AT-Rich Genome: Indel Mutation, Recombination, and Substitution Bias. Genome Biol Evol 2020; 12:2344-2354. [PMID: 32986811 PMCID: PMC7846184 DOI: 10.1093/gbe/evaa202] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/19/2020] [Indexed: 12/16/2022] Open
Abstract
Genome-wide nucleotide composition varies widely among species. Despite extensive research, the source of genome-wide nucleotide composition diversity remains elusive. Yeast mitochondrial genomes (mitogenomes) are highly A + T rich, and they provide a unique opportunity to study the evolution of AT-biased landscape. In this study, we sequenced ten complete mitogenomes of the Saccharomycodes ludwigii yeast with 8% G + C content, the lowest genome-wide %(G + C) in all published genomes to date. The S. ludwigii mitogenomes have high densities of short tandem repeats but severely underrepresented mononucleotide repeats. Comparative population genomics of these record-setting A + T-rich genomes shows dynamic indel mutations and strong mutation bias toward A/T. Indel mutations play a greater role in genomic variation among very closely related strains than nucleotide substitutions. Indels have resulted in presence–absence polymorphism of tRNAArg (ACG) among S. ludwigii mitogenomes. Interestingly, these mitogenomes have undergone recombination, a genetic process that can increase G + C content by GC-biased gene conversion. Finally, the expected equilibrium G + C content under mutation pressure alone is higher than observed G + C content, suggesting existence of mechanisms other than AT-biased mutation operating to increase A/T. Together, our findings shed new lights on mechanisms driving extremely AT-rich genomes.
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Affiliation(s)
- Duong T Nguyen
- Department of Biological Sciences, Wayne State University
| | - Baojun Wu
- Department of Biological Sciences, Wayne State University
| | - Shujie Xiao
- Department of Biological Sciences, Wayne State University
| | - Weilong Hao
- Department of Biological Sciences, Wayne State University
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18
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Yildiz G, Ozkilinc H. First characterization of the complete mitochondrial genome of fungal plant-pathogen Monilinia laxa which represents the mobile intron rich structure. Sci Rep 2020; 10:13644. [PMID: 32788650 PMCID: PMC7424523 DOI: 10.1038/s41598-020-70611-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 07/31/2020] [Indexed: 11/30/2022] Open
Abstract
Monilinia laxa is an important fungal plant pathogen causing brown rot on many stone and pome fruits worldwide. Mitochondrial genome (mitogenome) plays a critical role in evolutionary biology of the organisms. This study aimed to characterize the complete mitogenome of M. laxa by using next-generation sequencing and approaches of de novo assembly and annotation. The total length of the mitogenome of M. laxa was 178,357 bp, and its structure was circular. GC content of the mitogenome was 30.1%. Annotation of the mitogenome presented 2 ribosomal RNA (rRNA) genes, 32 transfer RNA genes (tRNA), 1 gene encoding mitochondrial ribosomal protein S3, 14 protein-coding genes and 15 open reading frame encoding hypothetical proteins. Moreover, the group I mobile introns encoding homing endonucleases including LAGLIDADG and GIY-YIG families were found both within coding regions (genic) and intergenic regions of the mitogenome, indicating an enlarged size and a dynamic structure of the mitogenome. Furthermore, a comparative mitogenomic analysis was performed between M. laxa and the three closely related fungal phytopathogen species (Botryotinia fuckeliana, Sclerotinia sclerotiorum and, S. borealis). Due to the number and distribution of introns, the large extent of structural rearrangements and diverse mitogenome sizes were detected among the species investigated. Monilinia laxa presented the highest number of homing endonucleases among the fungal species considered in the analyses. This study is the first to report a detailed annotation of the mitogenome of an isolate of M. laxa, providing a solid basis for further investigations of mitogenome variations for the other Monilinia pathogens causing brown rot disease.
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Affiliation(s)
- Gozde Yildiz
- Graduate School of Natural and Applied Sciences, MSc Program in Biomolecular Sciences, Canakkale Onsekiz Mart University, Çanakkale, Turkey
| | - Hilal Ozkilinc
- Graduate School of Natural and Applied Sciences, MSc Program in Biomolecular Sciences, Canakkale Onsekiz Mart University, Çanakkale, Turkey.
- Faculty of Arts and Sciences, Department of Molecular Biology and Genetics, Canakkale Onsekiz Mart University, Çanakkale, Turkey.
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19
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Mower JP. Variation in protein gene and intron content among land plant mitogenomes. Mitochondrion 2020; 53:203-213. [PMID: 32535166 DOI: 10.1016/j.mito.2020.06.002] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Revised: 05/24/2020] [Accepted: 06/08/2020] [Indexed: 12/20/2022]
Abstract
The functional content of the mitochondrial genome (mitogenome) is highly diverse across eukaryotes. Among land plants, our understanding of the variation in mitochondrial gene and intron content is improving from concerted efforts to densely sample mitogenomes from diverse land plants. Here I review the current state of knowledge regarding the diversity in content of protein genes and introns in the mitogenomes of all major land plant lineages. Mitochondrial protein gene content is largely conserved among mosses and liverworts, but it varies substantially among and within other land plant lineages due to convergent losses of genes encoding ribosomal proteins and, to a lesser extent, genes for proteins involved in cytochrome c maturation and oxidative phosphorylation. Mitochondrial intron content is fairly stable within each major land plant lineage, but highly variable among lineages, resulting from occasional gains and many convergent losses over time. Trans-splicing has evolved dozens of times in various vascular plant lineages, particularly those with relatively higher rates of mitogenomic rearrangement. Across eukaryotes, mitochondrial protein gene and intron content has been shaped massive convergent evolution.
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Affiliation(s)
- Jeffrey P Mower
- Center for Plant Science Innovation and Department of Agronomy and Horticulture, University of Nebraska, Lincoln, NE.
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20
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Kulik T, Brankovics B, van Diepeningen AD, Bilska K, Żelechowski M, Myszczyński K, Molcan T, Stakheev A, Stenglein S, Beyer M, Pasquali M, Sawicki J, Wyrȩbek J, Baturo-Cieśniewska A. Diversity of Mobile Genetic Elements in the Mitogenomes of Closely Related Fusarium culmorum and F. graminearum sensu stricto Strains and Its Implication for Diagnostic Purposes. Front Microbiol 2020; 11:1002. [PMID: 32528440 PMCID: PMC7263005 DOI: 10.3389/fmicb.2020.01002] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 04/24/2020] [Indexed: 12/19/2022] Open
Abstract
Much of the mitogenome variation observed in fungal lineages seems driven by mobile genetic elements (MGEs), which have invaded their genomes throughout evolution. The variation in the distribution and nucleotide diversity of these elements appears to be the main distinction between different fungal taxa, making them promising candidates for diagnostic purposes. Fungi of the genus Fusarium display a high variation in MGE content, from MGE-poor (Fusarium oxysporum and Fusarium fujikuroi species complex) to MGE-rich mitogenomes found in the important cereal pathogens F. culmorum and F. graminearum sensu stricto. In this study, we investigated the MGE variation in these latter two species by mitogenome analysis of geographically diverse strains. In addition, a smaller set of F. cerealis and F. pseudograminearum strains was included for comparison. Forty-seven introns harboring from 0 to 3 endonucleases (HEGs) were identified in the standard set of mitochondrial protein-coding genes. Most of them belonged to the group I intron family and harbored either LAGLIDADG or GIY-YIG HEGs. Among a total of 53 HEGs, 27 were shared by all fungal strains. Most of the optional HEGs were irregularly distributed among fungal strains/species indicating ancestral mosaicism in MGEs. However, among optional MGEs, one exhibited species-specific conservation in F. culmorum. While in F. graminearum s.s. MGE patterns in cox3 and in the intergenic spacer between cox2 and nad4L may facilitate the identification of this species. Thus, our results demonstrate distinctive traits of mitogenomes for diagnostic purposes of Fusaria.
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Affiliation(s)
- Tomasz Kulik
- Department of Botany and Nature Protection, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Balazs Brankovics
- Biointeractions & Plant Health, Wageningen Plant Research, Wageningen, Netherlands
| | | | - Katarzyna Bilska
- Department of Botany and Nature Protection, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Maciej Żelechowski
- Department of Botany and Nature Protection, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Kamil Myszczyński
- Department of Botany and Nature Protection, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland.,Molecular Biology Laboratory, Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, Olsztyn, Poland
| | - Tomasz Molcan
- Department of Animal Anatomy and Physiology, Faculty of Biology and Biotechnology, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Alexander Stakheev
- Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia
| | - Sebastian Stenglein
- National Scientific and Technical Research Council, Godoy Cruz, Argentina.,Universidad Nacional del Centro de la Provincia de Buenos Aires, Tandil, Argentina
| | - Marco Beyer
- Department of Environmental Research and Innovation, Agro-Environmental Systems, Luxembourg Institute of Science and Technology, Belval, Luxembourg
| | - Matias Pasquali
- Department of Food, Environmental and Nutritional Sciences, University of Milan, Milan, Italy
| | - Jakub Sawicki
- Department of Botany and Nature Protection, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Joanna Wyrȩbek
- Department of Botany and Nature Protection, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland
| | - Anna Baturo-Cieśniewska
- Laboratory of Phytopathology and Molecular Mycology, Department of Biology and Plant Protection, UTP University of Science and Technology, Bydgoszcz, Poland
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21
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Fonseca PLC, Badotti F, De-Paula RB, Araújo DS, Bortolini DE, Del-Bem LE, Azevedo VA, Brenig B, Aguiar ERGR, Góes-Neto A. Exploring the Relationship Among Divergence Time and Coding and Non-coding Elements in the Shaping of Fungal Mitochondrial Genomes. Front Microbiol 2020; 11:765. [PMID: 32411111 PMCID: PMC7202290 DOI: 10.3389/fmicb.2020.00765] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 03/30/2020] [Indexed: 12/24/2022] Open
Abstract
The order Hypocreales (Ascomycota) is composed of ubiquitous and ecologically diverse fungi such as saprobes, biotrophs, and pathogens. Despite their phylogenetic relationship, these species exhibit high variability in biomolecules production, lifestyle, and fitness. The mitochondria play an important role in the fungal biology, providing energy to the cells and regulating diverse processes, such as immune response. In spite of its importance, the mechanisms that shape fungal mitogenomes are still poorly understood. Herein, we investigated the variability and evolution of mitogenomes and its relationship with the divergence time using the order Hypocreales as a study model. We sequenced and annotated for the first time Trichoderma harzianum mitochondrial genome (mtDNA), which was compared to other 34 mtDNAs species that were publicly available. Comparative analysis revealed a substantial structural and size variation on non-coding mtDNA regions, despite the conservation of copy number, length, and structure of protein-coding elements. Interestingly, we observed a highly significant correlation between mitogenome length, and the number and size of non-coding sequences in mitochondrial genome. Among the non-coding elements, group I and II introns and homing endonucleases genes (HEGs) were the main contributors to discrepancies in mitogenomes structure and length. Several intronic sequences displayed sequence similarity among species, and some of them are conserved even at gene position, and were present in the majority of mitogenomes, indicating its origin in a common ancestor. On the other hand, we also identified species-specific introns that advocate for the origin by different mechanisms. Investigation of mitochondrial gene transfer to the nuclear genome revealed that nuclear copies of the nad5 are the most frequent while atp8, atp9, and cox3 could not be identified in any of the nuclear genomes analyzed. Moreover, we also estimated the divergence time of each species and investigated its relationship with coding and non-coding elements as well as with the length of mitogenomes. Altogether, our results demonstrated that introns and HEGs are key elements on mitogenome shaping and its presence on fast-evolving mtDNAs could be mostly explained by its divergence time, although the intron sharing profile suggests the involvement of other mechanisms on the mitochondrial genome evolution, such as horizontal transference.
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Affiliation(s)
- Paula L. C. Fonseca
- Molecular and Computational Biology of Fungi Laboratory, Department of Microbiology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Fernanda Badotti
- Department of Chemistry, Centro Federal de Educação Tecnológica de Minas Gerais, Belo Horizonte, Brazil
| | - Ruth B. De-Paula
- Department of Molecular and Cellular Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
| | - Daniel S. Araújo
- Molecular and Computational Biology of Fungi Laboratory, Department of Microbiology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Dener E. Bortolini
- Program of Bioinformatics, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Luiz-Eduardo Del-Bem
- Program of Bioinformatics, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
- Department of Botany, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Vasco A. Azevedo
- Program of Bioinformatics, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Bertram Brenig
- Institute of Veterinary Medicine, Burckhardtweg, University of Göttingen, Göttingen, Germany
| | - Eric R. G. R. Aguiar
- Program of Bioinformatics, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Aristóteles Góes-Neto
- Molecular and Computational Biology of Fungi Laboratory, Department of Microbiology, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
- Program of Bioinformatics, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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22
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Abstract
Allopolyploidy generates diversity by increasing the number of copies and sources of chromosomes. Many of the best-known evolutionary radiations, crops, and industrial organisms are ancient or recent allopolyploids. Allopolyploidy promotes differentiation and facilitates adaptation to new environments, but the tools to test its limits are lacking. Here we develop an iterative method of Hybrid Production (iHyPr) to combine the genomes of multiple budding yeast species, generating Saccharomyces allopolyploids of at least six species. When making synthetic hybrids, chromosomal instability and cell size increase dramatically as additional copies of the genome are added. The six-species hybrids initially grow slowly, but they rapidly regain fitness and adapt, even as they retain traits from multiple species. These new synthetic yeast hybrids and the iHyPr method have potential applications for the study of polyploidy, genome stability, chromosome segregation, and bioenergy. Many industrial organisms are the result of recent or ancient allopolypoidy events. Here the authors iteratively combine the genomes of six yeast species to generate a viable hybrid.
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23
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Tao YT, Suo F, Tusso S, Wang YK, Huang S, Wolf JBW, Du LL. Intraspecific Diversity of Fission Yeast Mitochondrial Genomes. Genome Biol Evol 2020; 11:2312-2329. [PMID: 31364709 PMCID: PMC6736045 DOI: 10.1093/gbe/evz165] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/18/2019] [Indexed: 02/07/2023] Open
Abstract
The fission yeast Schizosaccharomyces pombe is an important model organism, but its natural diversity and evolutionary history remain under-studied. In particular, the population genomics of the S. pombe mitochondrial genome (mitogenome) has not been thoroughly investigated. Here, we assembled the complete circular-mapping mitogenomes of 192 S. pombe isolates de novo, and found that these mitogenomes belong to 69 nonidentical sequence types ranging from 17,618 to 26,910 bp in length. Using the assembled mitogenomes, we identified 20 errors in the reference mitogenome and discovered two previously unknown mitochondrial introns. Analyzing sequence diversity of these 69 types of mitogenomes revealed two highly distinct clades, with only three mitogenomes exhibiting signs of inter-clade recombination. This diversity pattern suggests that currently available S. pombe isolates descend from two long-separated ancestral lineages. This conclusion is corroborated by the diversity pattern of the recombination-repressed K-region located between donor mating-type loci mat2 and mat3 in the nuclear genome. We estimated that the two ancestral S. pombe lineages diverged about 31 million generations ago. These findings shed new light on the evolution of S. pombe and the data sets generated in this study will facilitate future research on genome evolution.
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Affiliation(s)
- Yu-Tian Tao
- National Institute of Biological Sciences, Beijing, China.,Graduate School of Peking Union Medical College, Beijing, China
| | - Fang Suo
- National Institute of Biological Sciences, Beijing, China
| | - Sergio Tusso
- Division of Evolutionary Biology, Faculty of Biology, LMU Munich, Planegg-Martinsried, Germany.,Science for Life Laboratories, Department of Evolutionary Biology, Uppsala University, Sweden
| | - Yan-Kai Wang
- National Institute of Biological Sciences, Beijing, China
| | - Song Huang
- National Institute of Biological Sciences, Beijing, China.,Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, China
| | - Jochen B W Wolf
- Division of Evolutionary Biology, Faculty of Biology, LMU Munich, Planegg-Martinsried, Germany.,Science for Life Laboratories, Department of Evolutionary Biology, Uppsala University, Sweden
| | - Li-Lin Du
- National Institute of Biological Sciences, Beijing, China.,Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, China
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24
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Ye LY, Deng YJ, Mukhtar I, Meng GL, Song YJ, Cheng B, Hao JB, Wu XP. Mitochondrial genome and diverse inheritance patterns in Pleurotus pulmonarius. J Microbiol 2020; 58:142-152. [PMID: 31993988 DOI: 10.1007/s12275-020-9318-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 09/26/2019] [Accepted: 11/29/2019] [Indexed: 11/26/2022]
Abstract
Pleurotus pulmonarius, a member of the Pleurotaceae family in Basidiomycota, is an edible, economically important mushroom in most Asian countries. In this study, the complete mitochondrial genomes (mtDNA) of three P. pulmonarius strains - two monokaryotic commercial (J1-13 and ZA3) and one wild (X1-15) - were sequenced and analyzed. In ZA3 and X1-15, the mtDNA molecule was found to be a single circle of 68,305 bp and 73,435 bp, respectively. Both strains contain 14 core protein-coding genes and two ribosomal RNA (rRNA) subunit genes. The ZA3 strain has 22 transfer RNA (tRNA) genes and nine introns: eight in cytochrome c oxidase subunit 1 (coxl), and one in the rRNA large subunit (rnl). Monokaryotic J1-13 and ZA3 mtDNAs were found to be similar in their structure. However, the wild strain X1-15 contains 25 tRNA genes and only seven introns in coxl. Open reading frames (ORFs) of ZA3/J1-13 and X1-15 encode LAGLIDADG, ribosomal protein S3, and DNA polymerase II. In addition, mtDNA inheritance in J1-13, ZA3, and X1-15 was also studied. Results showed that the mtDNA inheritance pattern was uniparental and closely related to dikaryotic hyphal location with respect to the parent. Results also show that mtDNA inheritance is influenced by both the parental nuclear genome and mitogenome in the zone of contact between two compatible parents. In summary, this analysis provides valuable information and a basis for further studies to improve our understanding of the inheritance of fungal mtDNA.
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Affiliation(s)
- Li-Yun Ye
- Mycological Research Center, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, P. R. China
| | - You-Jin Deng
- Mycological Research Center, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, P. R. China
| | - Irum Mukhtar
- Mycological Research Center, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, P. R. China
| | - Guo-Liang Meng
- Mycological Research Center, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, P. R. China
| | - Yan-Jiao Song
- Mycological Research Center, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, P. R. China
| | - Bing Cheng
- Mycological Research Center, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, P. R. China
| | - Jin-Bing Hao
- Mycological Research Center, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, P. R. China
| | - Xiao-Ping Wu
- Mycological Research Center, College of Life Sciences, Fujian Agriculture and Forestry University, Fuzhou, 350002, P. R. China.
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Multilayered horizontal operon transfers from bacteria reconstruct a thiamine salvage pathway in yeasts. Proc Natl Acad Sci U S A 2019; 116:22219-22228. [PMID: 31611373 DOI: 10.1073/pnas.1909844116] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Horizontal acquisition of bacterial genes is presently recognized as an important contribution to the adaptation and evolution of eukaryotic genomes. However, the mechanisms underlying expression and consequent selection and fixation of the prokaryotic genes in the new eukaryotic setting are largely unknown. Here we show that genes composing the pathway for the synthesis of the essential vitamin B1 (thiamine) were lost in an ancestor of a yeast lineage, the Wickerhamiella/Starmerella (W/S) clade, known to harbor an unusually large number of genes of alien origin. The thiamine pathway was subsequently reassembled, at least twice, by multiple HGT events from different bacterial donors involving both single genes and entire operons. In the W/S-clade species Starmerella bombicola we obtained direct genetic evidence that all bacterial genes of the thiamine pathway are functional. The reconstructed pathway is composed by yeast and bacterial genes operating coordinately to scavenge thiamine derivatives from the environment. The adaptation of the newly acquired operons to the eukaryotic setting involved a repertoire of mechanisms until now only sparsely documented, namely longer intergenic regions, post-horizontal gene transfer (HGT) gene fusions fostering coordinated expression, gene relocation, and possibly recombination generating mosaic genes. The results provide additional evidence that HGT occurred recurrently in this yeast lineage and was crucial for the reestablishment of lost functions and that similar mechanisms are used across a broad range of eukaryotic microbes to promote adaptation of prokaryotic genes to their new environment.
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Wu B, Hao W. Mitochondrial‐encoded endonucleases drive recombination of protein‐coding genes in yeast. Environ Microbiol 2019; 21:4233-4240. [DOI: 10.1111/1462-2920.14783] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 08/18/2019] [Indexed: 01/15/2023]
Affiliation(s)
- Baojun Wu
- Department of Biological Sciences Wayne State University Detroit MI USA
| | - Weilong Hao
- Department of Biological Sciences Wayne State University Detroit MI USA
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Pogoda CS, Keepers KG, Nadiadi AY, Bailey DW, Lendemer JC, Tripp EA, Kane NC. Genome streamlining via complete loss of introns has occurred multiple times in lichenized fungal mitochondria. Ecol Evol 2019; 9:4245-4263. [PMID: 31016002 PMCID: PMC6467859 DOI: 10.1002/ece3.5056] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 02/12/2019] [Accepted: 02/22/2019] [Indexed: 12/22/2022] Open
Abstract
Reductions in genome size and complexity are a hallmark of obligate symbioses. The mitochondrial genome displays clear examples of these reductions, with the ancestral alpha-proteobacterial genome size and gene number having been reduced by orders of magnitude in most descendent modern mitochondrial genomes. Here, we examine patterns of mitochondrial evolution specifically looking at intron size, number, and position across 58 species from 21 genera of lichenized Ascomycete fungi, representing a broad range of fungal diversity and niches. Our results show that the cox1gene always contained the highest number of introns out of all the mitochondrial protein-coding genes, that high intron sequence similarity (>90%) can be maintained between different genera, and that lichens have undergone at least two instances of complete, genome-wide intron loss consistent with evidence for genome streamlining via loss of parasitic, noncoding DNA, in Phlyctis boliviensisand Graphis lineola. Notably, however, lichenized fungi have not only undergone intron loss but in some instances have expanded considerably in size due to intron proliferation (e.g., Alectoria fallacina and Parmotrema neotropicum), even between closely related sister species (e.g., Cladonia). These results shed light on the highly dynamic mitochondrial evolution that is occurring in lichens and suggest that these obligate symbiotic organisms are in some cases undergoing recent, broad-scale genome streamlining via loss of protein-coding genes as well as noncoding, parasitic DNA elements.
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Affiliation(s)
- Cloe S. Pogoda
- Department of Ecology and Evolutionary BiologyUniversity of ColoradoBoulderColorado
| | - Kyle G. Keepers
- Department of Ecology and Evolutionary BiologyUniversity of ColoradoBoulderColorado
| | - Arif Y. Nadiadi
- Department of Ecology and Evolutionary BiologyUniversity of ColoradoBoulderColorado
| | - Dustin W. Bailey
- Department of Ecology and Evolutionary BiologyUniversity of ColoradoBoulderColorado
| | - James C. Lendemer
- Institute of Systematic BotanyThe New York Botanical GardenBronxNew York
| | - Erin A. Tripp
- Department of Ecology and Evolutionary BiologyUniversity of ColoradoBoulderColorado
- Museum of Natural HistoryUniversity of ColoradoBoulderColorado
| | - Nolan C. Kane
- Department of Ecology and Evolutionary BiologyUniversity of ColoradoBoulderColorado
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Wai A, Shen C, Carta A, Dansen A, Crous PW, Hausner G. Intron-encoded ribosomal proteins and N-acetyltransferases within the mitochondrial genomes of fungi: here today, gone tomorrow? Mitochondrial DNA A DNA Mapp Seq Anal 2019; 30:573-584. [DOI: 10.1080/24701394.2019.1580272] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Alvan Wai
- Department of Microbiology, University of Manitoba, Winnipeg, Canada
| | - Chen Shen
- Department of Microbiology, University of Manitoba, Winnipeg, Canada
| | - Andrell Carta
- Department of Microbiology, University of Manitoba, Winnipeg, Canada
| | - Alexandra Dansen
- Department of Microbiology, University of Manitoba, Winnipeg, Canada
| | - Pedro W. Crous
- The Westerdijk Fungal Biodiversity Institute, Uppsalalaan 8, Utrecht, The Netherlands
| | - Georg Hausner
- Department of Microbiology, University of Manitoba, Winnipeg, Canada
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Zubaer A, Wai A, Hausner G. The mitochondrial genome of Endoconidiophora resinifera is intron rich. Sci Rep 2018; 8:17591. [PMID: 30514960 PMCID: PMC6279837 DOI: 10.1038/s41598-018-35926-y] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 11/08/2018] [Indexed: 02/07/2023] Open
Abstract
Endoconidiophora resinifera (=Ceratocystis resinifera) is a blue-stain fungus that occurs on conifers. The data showed that the Endoconidiophora resinifera mitochondrial genome is one of the largest mitochondrial genomes (>220 kb) so far reported among members of the Ascomycota. An exceptional large number of introns (81) were noted and differences among the four strains were restricted to minor variations in intron numbers and a few indels and single nucleotide polymorphisms. The major differences among the four strains examined are due to size polymorphisms generated by the absence or presence of mitochondrial introns. Also, these mitochondrial genomes encode the largest cytochrome oxidase subunit 1 gene (47.5 kb) reported so far among the fungi. The large size for this gene again can be attributed to the large number of intron insertions. This study reports the first mitochondrial genome for the genus Endoconidiophora, previously members of this genus were assigned to Ceratocystis. The latter genus has recently undergone extensive taxonomic revisions and the mitochondrial genome might provide loci that could be applied as molecular markers assisting in the identification of taxa within this group of economically important fungi. The large mitochondrial genome also may provide some insight on mechanisms that can lead to mitochondrial genome expansion.
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Affiliation(s)
- Abdullah Zubaer
- Department of Microbiology, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada
| | - Alvan Wai
- Department of Microbiology, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada
| | - Georg Hausner
- Department of Microbiology, University of Manitoba, Winnipeg, MB, R3T 2N2, Canada.
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Xiao S, Nguyen DT, Wu B, Hao W. Genetic Drift and Indel Mutation in the Evolution of Yeast Mitochondrial Genome Size. Genome Biol Evol 2018; 9:3088-3099. [PMID: 29126284 PMCID: PMC5714193 DOI: 10.1093/gbe/evx232] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/07/2017] [Indexed: 12/27/2022] Open
Abstract
Mitochondrial genomes (mitogenomes) are remarkably diverse in genome size and organization, but the origins of dynamic mitogenome architectures are still poorly understood. For instance, the mutational burden hypothesis postulates that the drastic difference between large plant mitogenomes and streamlined animal mitogenomes can be driven by their different mutation rates. However, inconsistent trends between mitogenome sizes and mutation rates have been documented in several lineages. These conflicting results highlight the need of systematic and sophisticated investigations on the evolution and diversity of mitogenome architecture. This study took advantage of the strikingly variable mitogenome size among different yeast species and also among intraspecific strains, examined sequence dynamics of introns, GC-clusters, tandem repeats, mononucleotide repeats (homopolymers) and evaluated their contributions to genome size variation. The contributions of these sequence features to mitogenomic variation are dependent on the timescale, over which extant genomes evolved from their last common ancestor, perhaps due to a combination of different turnover rates of mobile sequences, variable insertion spaces, and functional constraints. We observed a positive correlation between mitogenome size and the level of genetic drift, suggesting that mitogenome expansion in yeast is likely driven by multiple types of sequence insertions in a primarily nonadaptive manner. Although these cannot be explained directly by the mutational burden hypothesis, our results support an important role of genetic drift in the evolution of yeast mitogenomes.
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Affiliation(s)
- Shujie Xiao
- Department of Biological Sciences, Wayne State University
| | - Duong T Nguyen
- Department of Biological Sciences, Wayne State University
| | - Baojun Wu
- Department of Biological Sciences, Wayne State University.,Department of Biology, Clark University, Worcester, MA
| | - Weilong Hao
- Department of Biological Sciences, Wayne State University
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31
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Yan Z, Li Z, Yan L, Yu Y, Cheng Y, Chen J, Liu Y, Gao C, Zeng L, Sun X, Guo L, Xu J. Deletion of the sex-determining gene SXI1α enhances the spread of mitochondrial introns in Cryptococcus neoformans. Mob DNA 2018; 9:24. [PMID: 30026817 PMCID: PMC6048814 DOI: 10.1186/s13100-018-0129-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 07/10/2018] [Indexed: 01/19/2023] Open
Abstract
Background Homing endonuclease genes (HEGs) are widely distributed genetic elements in the mitochondrial genomes of a diversity of eukaryotes. Due to their ability to self-propagate within and between genomes, these elements can spread rapidly in populations. Whether and how such elements are controlled in genomes remains largely unknown. Results Here we report that the HEG-containing introns in the mitochondrial COX1 gene in Cryptococcus neoformans are mobile and that their spread in sexual crosses is influenced by mating type (MAT) α-specific homeodomain gene SXI1α. C. neoformans has two mating types, MATa and MATα. In typical crosses between strains of the two mating types, only a small portion (< 7%) of diploid fusants inherited the HEGs from the MATα parent. However, disruption of the SXI1α gene resulted in the majority (> 95%) of the diploid fusants inheriting the HEG-containing introns from the MATα parent, a frequency significantly higher than those of intronless mitochondrial genes. Conclusions Our results suggest that SXI1α not only determines uniparental mitochondrial inheritance but also inhibits the spread of HEG-containing introns in the mitochondrial genome in C. neoformans.
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Affiliation(s)
- Zhun Yan
- 1Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha, 410205 Hunan China
| | - Zhimin Li
- 1Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha, 410205 Hunan China
| | - Li Yan
- 1Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha, 410205 Hunan China
| | - Yongting Yu
- 1Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha, 410205 Hunan China
| | - Yi Cheng
- 1Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha, 410205 Hunan China
| | - Jia Chen
- 1Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha, 410205 Hunan China
| | - Yunyun Liu
- 1Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha, 410205 Hunan China
| | - Chunsheng Gao
- 1Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha, 410205 Hunan China
| | - Liangbin Zeng
- 1Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha, 410205 Hunan China
| | - Xiangping Sun
- 1Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha, 410205 Hunan China
| | - Litao Guo
- 1Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha, 410205 Hunan China
| | - Jianping Xu
- 2Department of Biology, McMaster University, Hamilton, ON L8S 4K1 Canada
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Wu B, Macielog AI, Hao W. Origin and Spread of Spliceosomal Introns: Insights from the Fungal Clade Zymoseptoria. Genome Biol Evol 2018; 9:2658-2667. [PMID: 29048531 PMCID: PMC5647799 DOI: 10.1093/gbe/evx211] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/29/2017] [Indexed: 12/16/2022] Open
Abstract
Spliceosomal introns are a key feature of eukaryote genome architecture and have been proposed to originate from selfish group II introns from an endosymbiotic bacterium, that is, the ancestor of mitochondria. However, the mechanisms underlying the wide spread of spliceosomal introns across eukaryotic genomes have been obscure. In this study, we characterize the dynamic evolution of spliceosomal introns in the fungal genus Zymoseptoria at different evolutionary scales, that is, within a genome, among conspecific strains within species, and between different species. Within the genome, spliceosomal introns can proliferate in unrelated genes and intergenic regions. Among conspecific strains, spliceosomal introns undergo rapid turnover (gains and losses) and frequent sequence exchange between geographically distinct strains. Furthermore, spliceosomal introns could undergo introgression between distinct species, which can further promote intron invasion and proliferation. The dynamic invasion and proliferation processes of spliceosomal introns resemble the life cycles of mobile selfish (group I/II) introns, and these intron movements, at least in part, account for the dramatic processes of intron gain and intron loss during eukaryotic evolution.
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Affiliation(s)
- Baojun Wu
- Department of Biology, Clark University, Worcester, MA, USA
| | | | - Weilong Hao
- Department of Biological Sciences, Wayne State University
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Korovesi AG, Ntertilis M, Kouvelis VN. Mt-rps3 is an ancient gene which provides insight into the evolution of fungal mitochondrial genomes. Mol Phylogenet Evol 2018; 127:74-86. [PMID: 29763662 DOI: 10.1016/j.ympev.2018.04.037] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Revised: 02/24/2018] [Accepted: 04/23/2018] [Indexed: 12/30/2022]
Abstract
The nuclear ribosomal protein S3 (Rps3) is implicated in the assembly of the ribosomal small subunit. Fungi and plants present a gene copy in their mitochondrial (mt) genomes. An analysis of 303 complete fungal mt genomes showed that, when rps3 is found, it is either a free-standing gene or an anchored gene within the omega intron of the rnl gene. Early divergent fungi, Basidiomycota and all yeasts but the CTG group belong to the first case, and Pezizomycotina to the second. Its position, size and genetic code employed are conserved within species of the same Order. Size variability is attributed to different number of repeats. These repeats consist of AT-rich sequences. MtRps3 proteins lack the KH domain, necessary for binding to rRNA, in their N-terminal region. Their C-terminal region is conserved in all Domains of life. Phylogenetic analysis showed that nuclear and mtRps3 proteins are descendants of archaeal and a-proteobacterial homologues, respectively. Thus, fungal mt-rps3 gene is an ancient gene which evolved within the endosymbiotic model and presents different evolutionary routes: (a) coming from a-proteobacteria, it was relocated to another region of the mt genome, (b) via its insertion to the omega intron, it was transferred to the nucleus and/or got lost, and (c) it was re-routed to the mt genome again. Today, Basidiomycota and Saccharomycetales seem to follow the first evolutionary route and almost all Pezizomycotina support the second scenario with their exceptions being the result of the third scenario, i.e., the gene's re-entry to the mt genome.
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Affiliation(s)
- Artemis G Korovesi
- Department of Genetics and Biotechnology, Faculty of Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - Maria Ntertilis
- Department of Genetics and Biotechnology, Faculty of Biology, National and Kapodistrian University of Athens, Athens, Greece
| | - Vassili N Kouvelis
- Department of Genetics and Biotechnology, Faculty of Biology, National and Kapodistrian University of Athens, Athens, Greece.
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Abboud TG, Zubaer A, Wai A, Hausner G. The complete mitochondrial genome of the Dutch elm disease fungus Ophiostoma novo-ulmi subsp. novo-ulmi. Can J Microbiol 2018; 64:339-348. [DOI: 10.1139/cjm-2017-0605] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Ophiostoma novo-ulmi, a member of the Ophiostomatales (Ascomycota), is the causal agent of the current Dutch elm disease pandemic in Europe and North America. The complete mitochondrial genome (mtDNA) of Ophiostoma novo-ulmi subsp. novo-ulmi, the European component of O. novo-ulmi, has been sequenced and annotated. Gene order (synteny) among the currently available members of the Ophiostomatales was examined and appears to be conserved, and mtDNA size variability among the Ophiostomatales is due in part to the presence of introns and their encoded open reading frames. Phylogenetic analysis of concatenated mitochondrial protein-coding genes yielded phylogenetic estimates for various members of the Ophiostomatales, with strong statistical support showing that mtDNA analysis may provide valuable insights into the evolution of the Ophiostomatales.
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Affiliation(s)
- Talal George Abboud
- Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
- Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Abdullah Zubaer
- Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
- Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Alvan Wai
- Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
- Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
| | - Georg Hausner
- Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
- Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada
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Guha TK, Wai A, Mullineux ST, Hausner G. The intron landscape of the mtDNA cytb gene among the Ascomycota: introns and intron-encoded open reading frames. Mitochondrial DNA A DNA Mapp Seq Anal 2017; 29:1015-1024. [DOI: 10.1080/24701394.2017.1404042] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Tuhin K. Guha
- Department of Microbiology, University of Manitoba, Winnipeg, Canada
| | - Alvan Wai
- Department of Microbiology, University of Manitoba, Winnipeg, Canada
| | | | - Georg Hausner
- Department of Microbiology, University of Manitoba, Winnipeg, Canada
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Franco MEE, López SMY, Medina R, Lucentini CG, Troncozo MI, Pastorino GN, Saparrat MCN, Balatti PA. The mitochondrial genome of the plant-pathogenic fungus Stemphylium lycopersici uncovers a dynamic structure due to repetitive and mobile elements. PLoS One 2017; 12:e0185545. [PMID: 28972995 PMCID: PMC5626475 DOI: 10.1371/journal.pone.0185545] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 09/14/2017] [Indexed: 12/23/2022] Open
Abstract
Stemphylium lycopersici (Pleosporales) is a plant-pathogenic fungus that has been associated with a broad range of plant-hosts worldwide. It is one of the causative agents of gray leaf spot disease in tomato and pepper. The aim of this work was to characterize the mitochondrial genome of S. lycopersici CIDEFI-216, to use it to trace taxonomic relationships with other fungal taxa and to get insights into the evolutionary history of this phytopathogen. The complete mitochondrial genome was assembled into a circular double-stranded DNA molecule of 75,911 bp that harbors a set of 37 protein-coding genes, 2 rRNA genes (rns and rnl) and 28 tRNA genes, which are transcribed from both sense and antisense strands. Remarkably, its gene repertoire lacks both atp8 and atp9, contains a free-standing gene for the ribosomal protein S3 (rps3) and includes 13 genes with homing endonuclease domains that are mostly located within its 15 group I introns. Strikingly, subunits 1 and 2 of cytochrome oxidase are encoded by a single continuous open reading frame (ORF). A comparative mitogenomic analysis revealed the large extent of structural rearrangements among representatives of Pleosporales, showing the plasticity of their mitochondrial genomes. Finally, an exhaustive phylogenetic analysis of the subphylum Pezizomycotina based on mitochondrial data reconstructed their relationships in concordance with several studies based on nuclear data. This is the first report of a mitochondrial genome belonging to a representative of the family Pleosporaceae.
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Affiliation(s)
- Mario Emilio Ernesto Franco
- Centro de Investigaciones de Fitopatología, Facultad de Ciencias Agrarias y Forestales, Universidad Nacional de La Plata - Comisión de Investigaciones Científicas de la Provincia de Buenos Aires, La Plata, Buenos Aires, Argentina
| | - Silvina Marianela Yanil López
- Centro de Investigaciones de Fitopatología, Facultad de Ciencias Agrarias y Forestales, Universidad Nacional de La Plata - Comisión de Investigaciones Científicas de la Provincia de Buenos Aires, La Plata, Buenos Aires, Argentina
| | - Rocio Medina
- Centro de Investigaciones de Fitopatología, Facultad de Ciencias Agrarias y Forestales, Universidad Nacional de La Plata - Comisión de Investigaciones Científicas de la Provincia de Buenos Aires, La Plata, Buenos Aires, Argentina
| | - César Gustavo Lucentini
- Centro de Investigaciones de Fitopatología, Facultad de Ciencias Agrarias y Forestales, Universidad Nacional de La Plata - Comisión de Investigaciones Científicas de la Provincia de Buenos Aires, La Plata, Buenos Aires, Argentina
| | - Maria Inés Troncozo
- Cátedra de Microbiología Agrícola, Facultad de Ciencias Agrarias y Forestales, Universidad Nacional de La Plata, La Plata, Buenos Aires, Argentina
| | - Graciela Noemí Pastorino
- Cátedra de Microbiología Agrícola, Facultad de Ciencias Agrarias y Forestales, Universidad Nacional de La Plata, La Plata, Buenos Aires, Argentina
| | - Mario Carlos Nazareno Saparrat
- Cátedra de Microbiología Agrícola, Facultad de Ciencias Agrarias y Forestales, Universidad Nacional de La Plata, La Plata, Buenos Aires, Argentina
- Instituto de Botánica Carlos Spegazzini, Facultad de Ciencias Naturales y Museo, Universidad Nacional de La Plata, La Plata, Buenos Aires, Argentina
- Instituto de Fisiología Vegetal, Facultad de Ciencias Naturales y Museo-Facultad de Ciencias Agrarias y Forestales, Universidad Nacional de La Plata - Consejo Nacional de Investigaciones Científicas y Técnicas, La Plata, Buenos Aires, Argentina
| | - Pedro Alberto Balatti
- Centro de Investigaciones de Fitopatología, Facultad de Ciencias Agrarias y Forestales, Universidad Nacional de La Plata - Comisión de Investigaciones Científicas de la Provincia de Buenos Aires, La Plata, Buenos Aires, Argentina
- Cátedra de Microbiología Agrícola, Facultad de Ciencias Agrarias y Forestales, Universidad Nacional de La Plata, La Plata, Buenos Aires, Argentina
- * E-mail:
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37
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Bilto IM, Hausner G. The diversity of mtDNA rns introns among strains of Ophiostoma piliferum, Ophiostoma pluriannulatum and related species. SPRINGERPLUS 2016; 5:1408. [PMID: 27610327 PMCID: PMC4995192 DOI: 10.1186/s40064-016-3076-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 08/15/2016] [Indexed: 02/08/2023]
Abstract
Background Based on previous studies, it was suspected that the mitochondrial rns gene within the Ophiostomatales is rich in introns. This study focused on a collection of strains representing Ophiostoma piliferum, Ophiostoma pluriannulatum and related species that cause blue-stain; these fungi colonize the sapwood of trees and impart a dark stain. This reduces the value of the lumber. The goal was to examine the mtDNA rns intron landscape for these important blue stain fungi in order to facilitate future annotation of mitochondrial genomes (mtDNA) and to potentially identify mtDNA introns that can encode homing endonucleases which may have applications in biotechnology. Results Comparative sequence analysis identified five intron insertion sites among the ophiostomatoid fungi examined. Positions mS379 and mS952 harbor group II introns, the mS379 intron encodes a reverse transcriptase, and the mS952 intron encodes a potential homing endonuclease. Positions mS569, mS1224, and mS1247 have group I introns inserted and these encode intact or eroded homing endonuclease open reading frames (ORF). Phylogenetic analysis of the intron ORFs showed that they can be found in the same insertion site in closely and distantly related species. Conclusions Based on the molecular markers examined (rDNA internal transcribed spacers and rns introns), strains representing O. pilifera, O. pluriannulatum and Ophiostoma novae-zelandiae could not be resolved. Phylogenetic studies suggest that introns are gained and lost and that horizontal transfer could explain the presence of related intron in distantly related fungi. With regard to the mS379 group II intron, this study shows that mitochondrial group II introns and their reverse transcriptases may also follow the life cycle previously proposed for group I introns and their homing endonucleases. This consists of intron invasion, decay of intron ORF, loss of intron, and possible reinvasion. Electronic supplementary material The online version of this article (doi:10.1186/s40064-016-3076-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Iman M Bilto
- Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2 Canada
| | - Georg Hausner
- Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2 Canada
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Qi Z, Ding S. Targeting mitochondrial phenotypes for non-communicable diseases. JOURNAL OF SPORT AND HEALTH SCIENCE 2016; 5:155-158. [PMID: 30356553 PMCID: PMC6188743 DOI: 10.1016/j.jshs.2016.04.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 03/04/2016] [Accepted: 03/27/2016] [Indexed: 06/08/2023]
Abstract
The concept that "Exercise is Medicine" has been challenged by the rising prevalence of non-communicable chronic diseases (NCDs). This is partly due to the fact that the underlying mechanisms of how exercise influences energy homeostasis and counteracts high-fat diets and physical inactivity is complex and remains relatively poorly understood on a molecular level. In addition to genetic polymorphisms in humans that lead to gross variations in responsiveness to exercise, adaptation in mitochondrial networks is central to physical activity, inactivity, and diet. To harness the benefits of exercise for NCDs, much work still needs to be done to improve health effectively on a societal level such as developing personalized exercise interventions aided by advances in high-throughput genomics, proteomics, and metabolomics. We propose that understanding the mitochondrial phenotype according to the molecular information of genotypes, lifestyles, and exercise responsiveness in individuals will optimize exercise effects for prevention of NCDs.
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Affiliation(s)
- Zhengtang Qi
- The Key Laboratory of Adolescent Health Assessment and Exercise Intervention (East China Normal University), Ministry of Education, Shanghai 200241, China
- School of Physical Education and Health, East China Normal University, Shanghai 200241, China
| | - Shuzhe Ding
- The Key Laboratory of Adolescent Health Assessment and Exercise Intervention (East China Normal University), Ministry of Education, Shanghai 200241, China
- School of Physical Education and Health, East China Normal University, Shanghai 200241, China
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Wu B, Buljic A, Hao W. Extensive Horizontal Transfer and Homologous Recombination Generate Highly Chimeric Mitochondrial Genomes in Yeast. Mol Biol Evol 2015; 32:2559-70. [PMID: 26018571 DOI: 10.1093/molbev/msv127] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The frequency of horizontal gene transfer (HGT) in mitochondrial DNA varies substantially. In plants, HGT is relatively common, whereas in animals it appears to be quite rare. It is of considerable importance to understand mitochondrial HGT across the major groups of eukaryotes at a genome-wide level, but so far this has been well studied only in plants. In this study, we generated ten new mitochondrial genome sequences and analyzed 40 mitochondrial genomes from the Saccharomycetaceae to assess the magnitude and nature of mitochondrial HGT in yeasts. We provide evidence for extensive, homologous-recombination-mediated, mitochondrial-to-mitochondrial HGT occurring throughout yeast mitochondrial genomes, leading to genomes that are highly chimeric evolutionarily. This HGT has led to substantial intraspecific polymorphism in both sequence content and sequence divergence, which to our knowledge has not been previously documented in any mitochondrial genome. The unexpectedly high frequency of mitochondrial HGT in yeast may be driven by frequent mitochondrial fusion, relatively low mitochondrial substitution rates and pseudohyphal fusion to produce heterokaryons. These findings suggest that mitochondrial HGT may play an important role in genome evolution of a much broader spectrum of eukaryotes than previously appreciated and that there is a critical need to systematically study the frequency, extent, and importance of mitochondrial HGT across eukaryotes.
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Affiliation(s)
- Baojun Wu
- Department of Biological Sciences, Wayne State University
| | - Adnan Buljic
- Department of Biological Sciences, Wayne State University
| | - Weilong Hao
- Department of Biological Sciences, Wayne State University
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Abstract
Transposable elements (TEs) are an important factor shaping eukaryotic genomes. Although a significant body of research has been conducted on the abundance of TEs in nuclear genomes, TEs in mitochondrial genomes remain elusive. In this study, we successfully assembled 28 complete yeast mitochondrial genomes and took advantage of the power of population genomics to determine mobile DNAs and their propensity. We have observed compelling evidence of GC clusters propagating within the mitochondrial genome and being horizontally transferred between species. These mitochondrial TEs experience rapid diversification by nucleotide substitution and, more importantly, undergo dynamic merger and shuffling to form new TEs. Given the hyper mobile and transformable nature of mitochondrial TEs, our findings open the door to a deeper understanding of eukaryotic mitochondrial genome evolution and the origin of nonautonomous TEs.
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Comparison of mitochondrial genomes provides insights into intron dynamics and evolution in the caterpillar fungus Cordyceps militaris. Fungal Genet Biol 2015; 77:95-107. [PMID: 25896956 DOI: 10.1016/j.fgb.2015.04.009] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Revised: 04/09/2015] [Accepted: 04/11/2015] [Indexed: 12/16/2022]
Abstract
Intra-specific comparison of mitochondrial genomes can help elucidate the evolution of a species, however it has not been performed for hypocrealean fungi that form diverse symbiotic associations with other organisms. In this study, comparative analyses of three completely sequenced mitochondrial genomes of a hypocrealean fungus, Cordyceps militaris, the type species of Cordyceps genus, revealed that the introns were the main contributors to mitochondrial genome size variations among strains. Mitochondrial genes in C. militaris have been invaded by group I introns in at least eight positions. PCR assays of various C. militaris isolates showed abundant variations of intron presence/absence among strains at seven of the eight intronic loci. Although the ancestral intron pattern was inferred to contain all eight introns, loss and/or gain events occurred for seven of the eight introns. These introns invaded the C. militaris mitochondrial genome probably by horizontal transfer from other fungi, and intron insertions into intronless genes in C. militaris were accompanied by co-conversions of upstream exon sequences especially for those introns targeting protein-coding genes. We also detected phylogenetic congruence between the intron and exon trees at each individual locus, consistent with the ancestral mitochondria of C. militaris as having all eight introns. This study helps to explain the evolution of C. militaris mitochondrial genomes and will facilitate population genetic studies of this medicinally important fungus.
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Abstract
In virtually all multicellular eukaryotes, mitochondria are transmitted exclusively through one parent, usually the mother. In this short review, we discuss some of the major consequences of uniparental transmission of mitochondria, including deleterious effects in males and selection for increased transmission through females. Many of these consequences, particularly sex ratio distortion, have well-studied parallels in other maternally transmitted genetic elements, such as bacterial endosymbionts of arthropods. We also discuss the consequences of linkage between mitochondria and other maternally transmitted genetic elements, including the role of cytonuclear incompatibilities in maintaining polymorphism. Finally, as a case study, we discuss a recently discovered maternally transmitted sex ratio distortion in an insect that is associated with extraordinarily divergent mitochondria.
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Kim T, Hao W. DiscML: an R package for estimating evolutionary rates of discrete characters using maximum likelihood. BMC Bioinformatics 2014; 15:320. [PMID: 25260628 PMCID: PMC4261585 DOI: 10.1186/1471-2105-15-320] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2014] [Accepted: 09/25/2014] [Indexed: 11/17/2022] Open
Abstract
Background The study of discrete characters is crucial for the understanding of evolutionary processes. Even though great advances have been made in the analysis of nucleotide sequences, computer programs for non-DNA discrete characters are often dedicated to specific analyses and lack flexibility. Discrete characters often have different transition rate matrices, variable rates among sites and sometimes contain unobservable states. To obtain the ability to accurately estimate a variety of discrete characters, programs with sophisticated methodologies and flexible settings are desired. Results DiscML performs maximum likelihood estimation for evolutionary rates of discrete characters on a provided phylogeny with the options that correct for unobservable data, rate variations, and unknown prior root probabilities from the empirical data. It gives users options to customize the instantaneous transition rate matrices, or to choose pre-determined matrices from models such as birth-and-death (BD), birth-death-and-innovation (BDI), equal rates (ER), symmetric (SYM), general time-reversible (GTR) and all rates different (ARD). Moreover, we show application examples of DiscML on gene family data and on intron presence/absence data. Conclusion DiscML was developed as a unified R program for estimating evolutionary rates of discrete characters with no restriction on the number of character states, and with flexibility to use different transition models. DiscML is ideal for the analyses of binary (1s/0s) patterns, multi-gene families, and multistate discrete morphological characteristics. Electronic supplementary material The online version of this article (doi:10.1186/1471-2105-15-320) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | - Weilong Hao
- Department of Biological Sciences, Wayne State University, 48202 Detroit, USA.
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