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Jacquat AG, Theumer MG, Dambolena JS. Selective and non-selective evolutionary signatures found in the simplest replicative biological entities. J Evol Biol 2024; 37:862-876. [PMID: 38822575 DOI: 10.1093/jeb/voae070] [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: 11/23/2023] [Accepted: 05/30/2024] [Indexed: 06/03/2024]
Abstract
Mitoviruses, which are considered evolutionary relics of extinct alpha-proteobacteria RNA phages, represent one of the simplest self-replicating biological systems. This study aims to quantitatively describe genomes and identify potential genomic signatures that support the protein phylogenetic-based classification criterion. Genomic variables, such as mononucleotide and dinucleotide composition, codon usage bias, and minimal free energy derived from optimized predicted RNA secondary structure, were analyzed. From the values obtained, the main evolutionary pressures were discussed, indicating that natural selection plays a significant role in shaping mitovirus genomes. However, neutral evolution also makes a significant contribution. This study reveals a significant discovery of structural divergence in Kvaramitovirus. The energy minimization approach employed to study 2D folding in this study reveals a distinct spatial organization of their genomes, providing evidence for the hypothesis of a single evolutionary event of circularization in the most recent common ancestor of the lineage. This hypothesis was discussed in light of recent discoveries by other researchers that partially support the existence of mitoviruses with circular genomes. Finally, this study represents a significant advancement in the understanding of mitoviruses, as it quantitatively describes the nucleotide sequence at the family and genus taxonomic levels. Additionally, we provide hypotheses that can be experimentally validated to inspire new research and address the gaps in knowledge of this fascinating, basally divergent RNA virus lineage.
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Affiliation(s)
- Andrés Gustavo Jacquat
- Facultad de Ciencias Exactas Físicas y Naturales (FCEFyN), Universidad Nacional de Córdoba (UNC), Córdoba, Argentina
- Instituto Multidisciplinario de Biología Vegetal (IMBIV), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Córdoba, Argentina
| | - Martín Gustavo Theumer
- Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas (FCQ), Universidad Nacional de Córdoba (UNC), Córdoba, Argentina
- Centro de Investigaciones en Bioquímica Clínica e Inmunología (CIBICI), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Córdoba, Argentina
| | - José Sebastián Dambolena
- Facultad de Ciencias Exactas Físicas y Naturales (FCEFyN), Universidad Nacional de Córdoba (UNC), Córdoba, Argentina
- Instituto Multidisciplinario de Biología Vegetal (IMBIV), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Córdoba, Argentina
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Putative Mitoviruses without In-Frame UGA(W) Codons: Evolutionary Implications. Viruses 2023; 15:v15020340. [PMID: 36851553 PMCID: PMC9965874 DOI: 10.3390/v15020340] [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: 10/25/2022] [Revised: 01/22/2023] [Accepted: 01/24/2023] [Indexed: 01/27/2023] Open
Abstract
Mitoviruses are small vertically transmitted RNA viruses found in fungi, plants and animals. Taxonomically, a total of 105 species and 4 genera have been formally recognized by ICTV, and recently, 18 new putative species have been included in a new proposed genus. Transcriptomic and metatranscriptomic studies are a major source of countless new virus-like sequences that are continually being added to open databases and these may be good sources for identifying new putative mitoviruses. The search for mitovirus-like sequences in the NCBI databases resulted in the discovery of more than one hundred new putative mitoviruses, with important implications for taxonomy and also for the evolutionary scenario. Here, we propose the inclusion of four new putative members to the genus Kvaramitovirus, and the existence of a new large basally divergent lineage composed of 144 members that lack internal UGA codons (subfamily "Arkeomitovirinae"), a feature not shared by the vast majority of mitoviruses. Finally, a taxonomic categorization proposal and a detailed description of the evolutionary history of mitoviruses were carried out. This in silico study supports the hypothesis of the existence of a basally divergent lineage that could have had an impact on the early evolutionary history of mitoviruses.
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Discovery, Genomic Sequence Characterization and Phylogenetic Analysis of Novel RNA Viruses in the Turfgrass Pathogenic Colletotrichum spp. in Japan. Viruses 2022; 14:v14112572. [PMID: 36423181 PMCID: PMC9698584 DOI: 10.3390/v14112572] [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: 09/20/2022] [Revised: 11/14/2022] [Accepted: 11/16/2022] [Indexed: 11/22/2022] Open
Abstract
Turfgrass used in various areas of the golf course has been found to present anthracnose disease, which is caused by Colletotrichum spp. To obtain potential biological agents, we identified four novel RNA viruses and obtained full-length viral genomes from turfgrass pathogenic Colletotrichum spp. in Japan. We characterized two novel dsRNA partitiviruses: Colletotrichum associated partitivirus 1 (CaPV1) and Colletotrichum associated partitivirus 2 (CaPV2), as well as two negative single-stranded (ss) RNA viruses: Colletotrichum associated negative-stranded RNA virus 1 (CaNSRV1) and Colletotrichum associated negative-stranded RNA virus 2 (CaNSRV2). Using specific RT-PCR assays, we confirmed the presence of CaPV1, CaPV2 and CaNSRV1 in dsRNAs from original and sub-isolates of Colletotrichum sp. MBCT-264, as well as CaNSRV2 in dsRNAs from original and sub-isolates of Colletotrichum sp. MBCT-288. This is the first time mycoviruses have been discovered in turfgrass pathogenic Colletotrichum spp. in Japan. CaPV1 and CaPV2 are new members of the newly proposed genus "Zetapartitivirus" and genus Alphapartitivirus, respectively, in the family Partitiviridae, according to genomic characterization and phylogenetic analysis. Negative sense ssRNA viruses CaNSRV1 and CaNSRV2, on the other hand, are new members of the family Phenuiviridae and the proposed family "Mycoaspirividae", respectively. These findings reveal previously unknown RNA virus diversity and evolution in turfgrass pathogenic Colletotrichum spp.
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Ikeda A, Chiba Y, Kuroki M, Urayama SI, Hagiwara D. Efficient elimination of RNA mycoviruses in aspergillus species using RdRp-inhibitors ribavirin and 2'-C-methylribonucleoside derivatives. Front Microbiol 2022; 13:1024933. [PMID: 36274709 PMCID: PMC9583132 DOI: 10.3389/fmicb.2022.1024933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 09/21/2022] [Indexed: 12/03/2022] Open
Abstract
RNA viruses in fungi (mycoviruses) are model systems for understanding the relationships between eukaryotic microorganisms and RNA viruses. To reveal the effects of mycoviruses on host fungi, it is essential to compare the phenotypes between isogenic fungal isolates with or without RNA virus infection. Since active entry machinery for RNA mycoviruses has never been identified, introducing mycoviruses to fungi is a difficult and time-consuming process. Therefore, most studies have tried to generate virus-free isolates from infected strains by eliminating the mycovirus. However, methods of elimination have not been evaluated in a quantitative and comparative manner. In this study, we established a method to remove mycoviruses from host cells using the antiviral drugs ribavirin, 2'-C-methylcytidine (2CMC), 2'-C-methyladenosine (2CMA), and 7d2CMA, and compared the efficiency of removal in virus-infected strains of Aspergillus fumigatus. The results indicated that treatment with the drugs removed RNA viruses of diverse proportions in the families Chrysoviridae, Mitoviridae, Partitiviridae, Polymycoviridae, and an unclassified RNA virus group. Viruses belonging to Narnaviridae were hardly eliminated by these antiviral treatments when they were the sole infectious agents. We found that 2CMC showed activity against a wider range of RNA mycoviruses compared to ribavirin, 2CMA, and 7d2CMA, although 7d2CMA also efficiently removed dsRNA viruses from the families Chrysoviridae, Partitiviridae, and Polymycoviridae. These results indicated that removal of mycoviruses depends on the specific viral species and antiviral drug. This is the first report demonstrating a preferential antiviral effect against mycoviruses, which will enhance research on microbial RNA viruses and support their elimination from economically important fungi such as edible mushrooms.
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Affiliation(s)
- Ayano Ikeda
- Laboratory of Fungal Interaction and Molecular Biology (Donated by IFO), Department of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Yuto Chiba
- Laboratory of Fungal Interaction and Molecular Biology (Donated by IFO), Department of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Misa Kuroki
- Laboratory of Fungal Interaction and Molecular Biology (Donated by IFO), Department of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Syun-ichi Urayama
- Laboratory of Fungal Interaction and Molecular Biology (Donated by IFO), Department of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan,Microbiology Research Center for Sustainability (MiCS), University of Tsukuba, Tsukuba, Ibaraki, Japan,*Correspondence: Syun-ichi Urayama,
| | - Daisuke Hagiwara
- Laboratory of Fungal Interaction and Molecular Biology (Donated by IFO), Department of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan,Microbiology Research Center for Sustainability (MiCS), University of Tsukuba, Tsukuba, Ibaraki, Japan,Daisuke Hagiwara,
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