Ovid Technologies (Wolters Kluwer Health) Acta Medica Okayama 2047-9980 15 9 2026 Insomnia and the Risk of Atrial Fibrillation: A Nationwide, Real‐World Cohort Study e045149 EN Takuro Masuda Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Kentaro Ejiri Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Hidehiro Kaneko Department of Cardiovascular Medicine, The University of Tokyo Yuta Suzuki Department of Advanced Cardiology, The University of Tokyo Toru Miyoshi Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Satoshi Taya Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Keiichiro Iwasaki Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Koji Nakagawa Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Nobuhiro Nishii Department of Cardiovascular Therapeutics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Hiroshi Morita Department of Cardiovascular Therapeutics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Akira Okada Department of Prevention of Diabetes and Lifestyle-Related Diseases, Graduate School of Medicine, The University of Tokyo Katsuhito Fujiu Department of Cardiovascular Medicine, The University of Tokyo Norifumi Takeda Department of Cardiovascular Medicine, The University of Tokyo Hiroyuki Morita Department of Cardiovascular Medicine, The University of Tokyo Hideo Yasunaga Department of Clinical Epidemiology and Health Economics, School of Public Health, The University of Tokyo Norihiko Takeda Department of Cardiovascular Medicine, The University of Tokyo Shinsuke Yuasa Department of Cardiovascular Medicine, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Background: Insomnia is one of the most prevalent diseases observed in clinical practice, contributing to increased death and a range of chronic diseases. While numerous studies have explored the relationship between insomnia and cardiovascular disease, research on its association with atrial fibrillation (AF) remains limited. This study aimed to investigate the association between insomnia and incident AF in the general population by comprehensive, nationwide, real‐world data in Japan.<br> Methods: A total of 1 780 764 individuals without prior cardiovascular disease including AF from the DeSC database were included between April 2014 and August 2023. Insomnia was defined by International Classification of Diseases, Tenth Revision (ICD‐10) codes (F510, G470) before the baseline health checkup. The primary outcome was incident AF (I480–I482 and I489). Cox proportional hazards models were used to estimate hazard ratios of AF according to present insomnia (versus absent).<br> Results: Insomnia was observed in 216 919 individuals (12.2%), showing a significant association with incident AF after adjusting for potential confounding factors (adjusted hazard ratio, 1.14 [95% CI, 1.10–1.18]). Among subgroups, a similar pattern in the association between insomnia and incident AF was seen, while the association was stronger in younger individuals aged <65 years (versus ≥65 years) and women (versus men) (P for interaction=0.01 and 0.03, respectively).<br> Conclusions: Insomnia was significantly associated with the risk of AF. It highlighted the importance of recognizing insomnia as a risk factor for AF, given its high prevalence in the general population and the substantial impact of AF on quality of life and prognosis. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0168-1702 370 2026 Toward in planta studies of persistent fungal viruses in a model plant 199761 EN Paul Telengech Agrivirology Laboratory, Institute of Plant Science and Resources, Okayama University Sakae Hisano Agrivirology Laboratory, Institute of Plant Science and Resources, Okayama University Francesco Favaretto Agrivirology Laboratory, Institute of Plant Science and Resources, Okayama University Hiroaki Ichikawa Agrivirology Laboratory, Institute of Plant Science and Resources, Okayama University Kazuyuki Maruyama Agrivirology Laboratory, Institute of Plant Science and Resources, Okayama University Kiwamu Hyodo Agrivirology Laboratory, Institute of Plant Science and Resources, Okayama University Hideki Kondo Agrivirology Laboratory, Institute of Plant Science and Resources, Okayama University Nobuhiro Suzuki Agrivirology Laboratory, Institute of Plant Science and Resources, Okayama University A model plant, Nicotiana benthamiana, was examined as a host for persistent fungal viruses capable of crossing organismal kingdoms. Protoplasts of N. benthamiana were transfected with a mixture of virions of a betapartitivirus, Rosellinia necatrix partitivirus 18 (RnPV18), and an alphapartitivirus, RnPV19, and were then subjected to plantlet regeneration. Primary RT-PCR-based screening showed that nearly 100% of the resulting calli tested positive for RnPV18, whereas approximately 90% were positive for RnPV19. However, secondary screening performed at a later stage of tissue culture revealed that only 6% of the calli retained RnPV19, whereas approximately 33% retained RnPV18. These results suggest that the calli were chimeric, consisting of virus-infected and virus-free sectors, and that the partitiviruses were progressively lost during callus maintenance. It is also possible that these fungal partitiviruses were unable to fully adapt to, or counteract, host defense responses sufficiently to establish stable infection. We succeeded in obtaining RnPV18-positive calli and suspension cultures that maintained the virus at detectable levels, as shown by northern blotting, after prolonged subculture for at least 9 months. High-throughput small RNA analyses revealed both similarities and differences in virus-derived small RNA profiles among protoplasts, calli, and suspension cultures. Viral genome analyses further revealed developmental stage-specific and stage-independent substitutions compared with the RnPV18 genomic sequence maintained in the original fungal host. Interestingly, a C-to-U mutation in the RNA-dependent RNA polymerase-encoding region of RnPV18 was detected much more frequently in a particular line, designated B21, than in another stably RnPV18-infected line, P8, irrespective of whether the virus was maintained in suspension cultures or calli. This may explain why virus accumulation in B21 calli and suspension cultures was much lower than that in P8 cell cultures, as RNA-seq analyses showed 159 K counts per million for P8 versus 44 K counts per million for B21. Taken together, this study provides a platform for investigating partitiviruses and other ubiquitous persistent viruses, which are generally difficult to inoculate experimentally. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0168-1702 367 2026 Mycoviruses diversity in the black kōji mold, Aspergillus luchuensis (section Nigri) isolated from liquor-production environments in Japan 199724 EN Hideki Kondo Institute of Plant Science and Resources, Okayama University Misaki Nanaji Graduate School of Tokyo Kasei University Hitomi Sugahara Institute of Plant Science and Resources, Okayama University Miki Fujita Institute of Plant Science and Resources, Okayama University Ida Bagus Andika Northwest A&F University Nobuhiro Suzuki Institute of Plant Science and Resources, Okayama University Fujimori Fumihiro Graduate School of Tokyo Kasei University Some fungal species in the genus Aspergillus are economically important due to their role in the production of liquors and various foods; however, their viromes, which may affect their performance, remain unexplored. Therefore, this study examined the viromes of nine strains of Aspergillus luchuensis (section Nigri), the black kōji mold used in the production of shochu (a traditional Japanese liquor) in Japan. It identified virus-like sequences related to alterna-, partiti-, curvula, botourmia-, narna-like, and umbra-like viruses. Some sequences appear to represent new variants (e.g., alterna- and gammapartitiviruses), while many others correspond to novel viral species within established or proposed mycoviral families. All A. luchuensis strains harbored multiple virus infections, with 2 to 7 viruses per strain. Three alternavirus strains with four-segmented double-stranded RNA (dsRNA) genomes were confirmed, along with minor variants co-present with the predominant strains. Notably, a gammapartitivirus appears to have two additional dsRNA genome segments, along with two satellite-like short dsRNA segments in some fungal isolates. Furthermore, at least five short RNAs (0.48–1.31 kb) were identified, three of which are possibly satellite-like RNAs associated with novel single-stranded RNA viruses (botourmia- and umbra-like viruses). These findings reveal the great diversity of mycoviruses in A. luchuensis populations and lay the foundation for further investigation into their impact on fungal phenotypes and liquor production. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0168-1702 367 2026 Virome of the fungi associated with mushroom dry bubble disease 199714 EN Lóránt Hatvani Institute of Plant Science and Resources, Okayama University Sakae Hisano Institute of Plant Science and Resources, Okayama University Hideki Kondo Institute of Plant Science and Resources, Okayama University Hitomi Sugahara Institute of Plant Science and Resources, Okayama University Paul Telengech Institute of Plant Science and Resources, Okayama University Sabitree Shahi Institute of Plant Science and Resources, Okayama University Sarah Remi Ibiang Institute of Plant Science and Resources, Okayama University Sándor Kocsubé Department of Biotechnology and Microbiology, Faculty of Science and Informatics, University of Szeged Tünde Kartali Department of Biotechnology and Microbiology, Faculty of Science and Informatics, University of Szeged David A. Fitzpatrick Genome Evolution Laboratory, Department of Biology, Maynooth University Helen Grogan Teagasc Food Research Center, Horticulture Development Department Nobuhiro Suzuki Institute of Plant Science and Resources, Okayama University Dry bubble disease, attributed to the filamentous fungus Lecanicillium fungicola (Cordycipitaceae) results in huge yield losses in mushroom (Agaricus bisporus) cultivation worldwide. The possibilities for controlling the disease using commercial fungicides are highly limited, and therefore, there is an increasing demand for novel, alternative means of pest management. Our research objective was the comprehensive examination of viruses in the causal agents of dry bubble disease, which may open up an avenue for its virocontrol in the future. Out of 57 fungal isolates obtained from dry bubble-affected A. bisporus crops in various countries, 47 (82%) were confirmed by ITS (Internal Transcribed Spacer) sequence analysis as L. fungicola. In addition, different members of the genera Akanthomyces and Simplicillium (7 and 3 isolates, respectively), yet unknown to cause dry bubble symptoms, have also been detected. Cellulose column chromatography revealed the presence of double-stranded (ds) RNA in seven L. fungicola and three Akanthomyces sp. isolates, suggesting viral infection. The ten dsRNA-positive and eight randomly selected dsRNA-negative fungal strains were subjected to rRNA-depletion high-throughput RNA-sequencing analysis. The presence of seven new viruses representing four new species in the established families, Partitiviridae, Polymycoviridae, Botourmiaviridae and the narna-like virus group, and three previously established/proposed species in the families Chrysoviridae and “Mycovirgaviridae” were confirmed. The impact of the detected and identified viruses on their host fungi, and their potential applicability for virocontrol purposes will be examined in the future. This study provides the first detailed report on viruses of mushroom pathogenic fungi. No potential conflict of interest relevant to this article was reported.

Microbiology Society Acta Medica Okayama 0022-1317 106 12 2025 Thorough characterization of a new curvulavirid from a Japanese strain of Cryphonectria nitschkei 002177 EN Sabitree Shahi ​Institute of Plant Science and Resources, Okayama University Sakae Hisano ​Institute of Plant Science and Resources, Okayama University Wasiatus Sa'diyah ​Institute of Plant Science and Resources, Okayama University Yoshihiro Takaki ​Institute for Extra-cutting-edge Science and Technology Avant-garde Research (X-star), Japan Agency for Marine-Earth Science and Technology (JAMSTEC) Hideki Kondo ​Institute of Plant Science and Resources, Okayama University Nobuhiro Suzuki ​Institute of Plant Science and Resources, Okayama University A new curvulavirid was isolated from a Japanese strain of the filamentous ascomycete Cryphonectria nitschkei and thoroughly characterized. The virus termed Cryphonectria nitschkei curvulavirus 1 (CnCvV1) has a bi-segmented dsRNA genome. CnCvV1 dsRNA1 encodes an RNA-dependent RNA polymerase (592 amino acids), while dsRNA2 possesses two ORFs, one that encodes a protein associated with the genomic dsRNA and the other that encodes a hypothetical protein of unknown function. CnCvV1 could be experimentally introduced into another virus-free strain of C. nitschkei and two strains of different fungal species within the genus Cryphonectria (Cryphonectria parasitica and Cryphonectria carpinicola). Based on phenotypic comparison, the virus caused asymptomatic infection in the three newly established fungal strains. However, there was a reduced colony growth rate and increased CnCvV1 accumulation in an RNA silencing-deficient mutant (Δdcl2), relative to the wt strain EP155 of a model virus host fungus (C. parasitica). These findings suggest that CnCvV1 is targeted by RNA silencing in C. parasitica. This study provides a foundation for further exploration of curvulavirids that have been biologically understudied. No potential conflict of interest relevant to this article was reported.

MDPI AG Acta Medica Okayama 2076-3921 14 12 2025 Roles of ROS and NO in Plant Responses to Individual and Combined Salt Stress and Waterlogging 1455 EN Taufika Islam Anee Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University Nasser A. Sewelam Botany Department, Faculty of Science, Tanta University Nonnatus S. Bautista Institute of Biological Sciences, College of Arts and Sciences, University of the Philippines Los Baños Takashi Hirayama Institute of Plant Science and Resources, Okayama University Nobuhiro Suzuki Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University During the climate change era, plants are increasingly exposed to multiple environmental challenges occurring simultaneously or sequentially. Among these, salt stress and waterlogging are two major factors that severely constrain crop productivity worldwide and often occur together. To survive under such conditions, plants have evolved sophisticated systems to scavenge harmful levels of reactive oxygen species (ROS). Despite their cytotoxic potential, ROS also act as key signaling molecules that interact with nitric oxide (NO), Ca2+, protein kinases, ion homeostasis pathways, and plant hormones. These signaling and acclimatory mechanisms are closely associated with the functions of energy-regulating organelles—chloroplasts and mitochondria—which are major sources of ROS under both individual and combined stresses. While many of these responses are shared between salt stress, waterlogging and their combination, it is likely that specific signaling mechanisms are uniquely activated when both stresses occur together—mechanisms that cannot be inferred from responses to each stress alone. Such specificity may depend on precise coordination among organelle-derived signals and the tight regulation of their cross-communication. Within this network, ROS and NO likely serve as central hubs, fine-tuning the integration of multiple signaling pathways that enable plants to adapt to complex and fluctuating stress environments. No potential conflict of interest relevant to this article was reported.

Microbiology Society Acta Medica Okayama 0022-1317 106 7 2025 Summary of taxonomy changes ratified by the International Committee on Taxonomy of Viruses (ICTV) from the Fungal and Protist Viruses Subcommittee, 2025 002115 EN Sead Sabanadzovic Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University Chantal Abergel Information Génomique & Structurale, UMR7256, CNRS & Aix-Marseille Université, Marseille, IMM, IM2B, IOM Marı́a A. Ayllón Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid (UPM) Leticia Botella Forest Protection and Wildlife Management Mendel University in Brno Marta Canuti Department of Veterinary and Animal Sciences, University of Copenhagen Yuto Chiba School of Agriculture, Meiji University Jean-Michel Claverie Information Génomique & Structurale, UMR7256, CNRS & Aix-Marseille Université, Marseille, IMM, IM2B, IOM Robert H.A. Coutts School of Health, Medicine and Life Sciences, University of Hertfordshire Stefania Daghino Institute for Sustainable Plant Protection, National Research Council of Italy Livia Donaire Centro de Edafología y Biología Aplicada del Segura-CSIC Marco Forgia Institute for Sustainable Plant Protection, CNR Ondřej Hejna Department of Genetics and Biotechnologies, University of South Bohemia Jichun Jia College of Plant Protection, Shanxi Agricultural University Daohong Jiang College of Plant Science and Technology, Huazhong Agricultural University Ioly Kotta-Loizou School of Health, Medicine and Life Sciences, University of Hertfordshire Mart Krupovic Institut Pasteur, Université Paris Cité, CNRS UMR6047, Archaeal Virology Unit Andrew S. Lang Department of Biology, Memorial University of Newfoundland Matthieu Legendre Information Génomique & Structurale, UMR7256, CNRS & Aix-Marseille Université, Marseille, IMM, IM2B, IOM Shin-Yi Lee Marzano United States Department of Agriculture, Agricultural Research Service, Application Technology Research Unit Luca Nerva Council for Agricultural Research and Economics - Research Centre for Viticulture and Enology Judit Pénzes Department of Entomology, Texas A&M University Anna Poimala Natural Resources Institute Finland (Luke) Sofia Rigou Information Génomique & Structurale, UMR7256, CNRS & Aix-Marseille Université, Marseille, IMM, IM2B, IOM Yukiyo Sato Department of Biology, Institute for Plant Sciences, University of Cologne Wajeeha Shamsi Department of Molecular Biology and Genetics, Aarhus University Nobuhiro Suzuki Institute of Plant Science and Resources, Okayama University Massimo Turina Department of Plant Protection, School of Agriculture, The University of Jordan Syun-ichi Urayama Department of Life and Environmental Sciences, University of Tsukuba Eeva J. Vainio Natural Resources Institute Finland (Luke) Jiatao Xie College of Plant Science and Technology, Huazhong Agricultural University The Fungal and Protist Viruses Subcommittee (SC) of the International Committee on Taxonomy of Viruses (ICTV) has received a total of eight taxonomic proposals for the 2024 annual cycle. The extent of proposed changes varied, including nomenclatural updates, creation of new taxa and reorganization of established taxa. Following the ICTV procedures, all proposals were reviewed and voted upon by the members of the Executive Committee with ratification in March 2025. As a result, a total of 52 species in the families Botourmiaviridae and Marnaviridae were renamed to comply with the mandated binomial format. A new genus has been added to the dsRNA virus family Amalgaviridae, while two new families, Splipalmiviridae (Wolframvirales) and Mycoalphaviridae (Hepelivirales), were created to classify new groups of positive-sense (+) RNA mycoviruses. The class Arfiviricetes (Cressdnaviricota) was expanded by a new order Lineavirales and a new family Oomyviridae of ssDNA viruses. Additionally, a new class Orpoviricetes was created in the kingdom Orthornavirae to classify a group of bisegmented (+)RNA viruses reported from fungi and oomycetes. Finally, the order Pimascovirales was reorganized to better depict evolutionary relationships of pithoviruses and related viruses with large dsDNA genomes. The summary of updates in the taxonomy of fungal and protist viruses presented here is limited to taxa within the remit of this Subcommittee. For information on taxonomy changes on other fungal viruses closely related to animal and/or plant viruses, please see reports from sister ICTV Subcommittees (i.e. Plant Virus SC and Animal dsRNA and ssRNA(−) Viruses SC). No potential conflict of interest relevant to this article was reported.

Microbiology Society Acta Medica Okayama 0022-1317 106 7 2025 Virus taxonomy proposal summaries: a searchable and citable resource to disseminate virus taxonomy advances 002079 EN Richard Mayne Nuffield Department of Medicine, University of Oxford Peter Simmonds Nuffield Department of Medicine, University of Oxford Donald B. Smith Nuffield Department of Medicine, University of Oxford Evelien M. Adriaenssens Quadram Institute Bioscience Elliot J. Lefkowitz Department of Microbiology, University of Alabama at Birmingham Hanna M. Oksanen Molecular and Integrative Biosciences Research Programme, Faculty of Biological and Environmental Sciences, University of Helsinki Francisco Murilo Zerbini Departamento de Fitopatologia/BIOAGRO, Universidade Federal de Viçosa Poliane Alfenas-Zerbini Departamento de Microbiologia, Universidade Federal de Viçosa Frank O Aylward Department of Biological Sciences, Virginia Tech Juliana Freitas-Astúa Embrapa Cassava and Fruits, Cruz das Almas R. Curtis Hendrickson Department of Microbiology, University of Alabama at Birmingham Holly R. Hughes Centers for Disease Control and Prevention Mart Krupovic Institut Pasteur, Université Paris Cité, CNRS UMR6047, Archaeal Virology Unit Jens H. Kuhn Integrated Research Facility at Fort Detrick, National Institute of Allergy and Infectious Diseases, National Institutes of Health Małgorzata Łobocka Institute of Biochemistry and Biophysics of the Polish Academy of Sciences Arcady R. Mushegian Division of Molecular and Cellular Biosciences, National Science Foundation Judit Penzes Institute for Quantitative Biomedicine, Rutgers University Alejandro Reyes Muñoz Departamento de Ciencias Biológicas, Universidad de los Andes David L. Robertson MRC-University of Glasgow Centre for Virus Research Simon Roux Department of Energy, Joint Genome Institute, Lawrence Berkeley National Laboratory Luisa Rubino Consiglio Nazionale delle Ricerche, Istituto per la Protezione Sostenibile delle Piante, Sede Secondaria di Bari Sead Sabanadzovic Department of Agricultural Science and Plant Protection, Mississippi State University Nobuhiro Suzuki Institute of Plant Science and Resources, Okayama University Dann Turner Molecular Biology, University of the West of England Koenraad Van Doorslaer Department of Immunobiology, School of Animal and Comparative Biomedical Sciences, BIO5 Institute, University of Arizona Cancer Center Arvind Varsani The Biodesign Center for Fundamental and Applied Microbiomics, School of Life Sciences, Center for Evolution and Medicine, Arizona State University Taxonomic classification of cellular organisms requires the publication of descriptions and proposed names of species and the deposition of specimens. Virus taxonomy is developed through a different system of annual submission of formal taxonomy proposals (TPs) that can be submitted by anyone but are typically prepared by a study group appointed by the International Committee on Taxonomy of Viruses (ICTV) and consisting of experts on a particular group of viruses. These are initially evaluated by an expert subcommittee and by the executive committee (EC) of the ICTV. EC-approved TPs are then submitted for evaluation and a ratification vote by the wider ICTV membership. Following ratification, the new taxonomy is annually updated in the Master Species List, associated databases and bioinformatic resources. The process is consistent, creates traceability in assignments and supports a fully evaluated, hierarchical classification and nomenclature of all taxonomic ranks from species to realms. The structure also facilitates large-scale and coordinated changes to virus taxonomy, such as the recent introduction of a binomial species nomenclature.<br> TPs are available on the ICTV website after ratification, but they are not indexed in bibliographic databases and are not easily cited. Authors of TPs do not receive citation credit for adopted proposals, and their voluntary contributions are largely invisible in the published literature. For greater visibility of TPs and their authors, the ICTV will commence the annual publication of summaries of all TPs from each ICTV subcommittee. These summaries will provide a searchable compendium of all annual taxonomy changes and additions as well as direct links to the Master Species List and other ICTV bioinformatic resources. Their publication will provide due credit and citations for their authors, form the basis for disseminating taxonomy decisions and promote greater visibility and accessibility to taxonomy changes for the virology community. No potential conflict of interest relevant to this article was reported.

Wiley Acta Medica Okayama 2198-3844 2025 A Viral RNA Silencing Suppressor Modulates Reactive Oxygen Species Levels to Induce the Autophagic Degradation of Dicer‐Like and Argonaute‐Like Proteins e06572 EN Shiyu Zhai State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University Tianxing Pang State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University Shiyu Peng State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University Shenshen Zou Department of Plant Pathology, College of Plant Protection, Shandong Agricultural University Zhiping Deng Institute of Virology and Biotechnology, Zhejiang Academy of Agricultural Sciences Nobuhiro Suzuki Institute of Plant Science and Resources (IPSR), Okayama University Zhensheng Kang State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University Ida Bagus Andika State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University Liying Sun State Key Laboratory of Crop Stress Biology for Arid Areas and College of Plant Protection, Northwest A&F University Mounting evidence indicates that viruses exploit elevated reactive oxygen species (ROS) levels to promote replication and pathogenesis, yet the mechanistic underpinnings of this viral strategy remain elusive for many viral systems. This study uncovers a sophisticated viral counter-defense mechanism in the Cryphonectria hypovirus 1 (CHV1)-Fusarium graminearum system, where the viral p29 protein subverts host redox homeostasis to overcome antiviral responses. That p29 directly interacts with and inhibits the enzymatic activity of fungal NAD(P)H-dependent FMN reductase 1 (FMR1), leading to increased ROS accumulation and subsequent autophagy activation is demonstrated. Strikingly, this ROS-induced autophagy selectively targets for degradation two core antiviral RNA silencing components against CHV1 in F. graminearum, Dicer-like 2 (DCL2) and Argonaute-like 1 (AGL1), thereby compromising the host's primary antiviral defense system. Genetic analysis confirms this coordinated hijacking of host machineries, as CHV1 shows enhanced accumulation in the FMR1 knockout and reduced accumulation in autophagy-deficient fungal strains. This work reveals a tripartite interplay among oxidative stress, autophagy, and RNA silencing that CHV1 manipulates through p29 multifunctional activity. These findings provide a model for how viruses coordinately regulate distinct host defense systems to optimize infection. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0168-1702 351 2025 Evidence for the replication of a plant rhabdovirus in its arthropod mite vector 199522 EN Hideki Kondo Institute of Plant Science and Resources (IPSR), Okayama University Miki Fujita Institute of Plant Science and Resources (IPSR), Okayama University Paul Telengech Institute of Plant Science and Resources (IPSR), Okayama University Kazuyuki Maruyam Institute of Plant Science and Resources (IPSR), Okayama University Kiwamu Hyodo Institute of Plant Science and Resources (IPSR), Okayama University Aline Daniele Tassi Tropical Research and Education Center, University of Florida Ronald Ochoa Systematic Entomology Laboratory, USDA Ida Bagus Andika College of Plant Protection, Northwest A&F University Nobuhiro Suzuki Institute of Plant Science and Resources (IPSR), Okayama University Transmission of plant viruses that replicate in the insect vector is known as persistent-propagative manner. However, it remains unclear whether such virus-vector relationships also occur between plant viruses and other biological vectors such as arthropod mites. In this study, we investigated the possible replication of orchid fleck virus (OFV), a segmented plant rhabdovirus, within its mite vector (Brevipalpus californicus s.l.) using quantitative RT-qPCR, western blotting and next-generation sequencing. Time-course RT-qPCR and western blot analyses showed an increasing OFV accumulation pattern in mites after virus acquisition. Since OFV genome expression requires the transcription of polyadenylated mRNAs, polyadenylated RNA fractions extracted from the viruliferous mite samples and OFV-infected plant leaves were used for RNA-seq analysis. In the mite and plant datasets, a large number of sequence reads were aligned to genomic regions of OFV RNA1 and RNA2 corresponding to transcribed viral gene mRNAs. This includes the short polyadenylated transcripts originating from the leader and trailer regions at the ends of the viral genome, which are believed to play a crucial role in viral transcription/replication. In contrast, a low number of reads were mapped to the non-transcribed regions (gene junctions). These results strongly suggested that OFV gene expression occurs both in mites and plants. Additionally, deep sequencing revealed the accumulation of OFV-derived small RNAs in mites, although their size profiles differ from those found in plants. Taken together, our results indicated that OFV replicates within a mite vector and is targeted by the RNA-silencing mechanism. No potential conflict of interest relevant to this article was reported.

MDPI AG Acta Medica Okayama 1999-4915 16 7 2024 Metatranscriptomic Sequencing of Sheath Blight-Associated Isolates of Rhizoctonia solani Revealed Multi-Infection by Diverse Groups of RNA Viruses 1152 EN Michael Louie R. Urzo Microbiology Division, Institute of Biological Sciences, College of Arts and Sciences, University of the Philippines Los Baños Timothy D. Guinto Microbiology Division, Institute of Biological Sciences, College of Arts and Sciences, University of the Philippines Los Baños Ana Eusebio-Cope Fit-for-Future Genetic Resources Unit, Rice Breeding Innovations Department, International Rice Research Institute (IRRI), University of the Philippines Los Baños Bernard O. Budot Institute of Weed Science, Entomology, and Plant Pathology, College of Agriculture and Food Science, University of the Philippines Los Baños Mary Jeanie T. Yanoria Traits for Challenged Environments Unit, Rice Breeding Innovations Department, International Rice Research Institute (IRRI), University of the Philippines Los Baños Gilda B. Jonson Traits for Challenged Environments Unit, Rice Breeding Innovations Department, International Rice Research Institute (IRRI), University of the Philippines Los Baños Masao Arakawa Faculty of Agriculture, Meijo University Hideki Kondo Plant-Microbe Interactions Group, Institute of Plant Science and Resources (IPSR), Okayama University Nobuhiro Suzuki Plant-Microbe Interactions Group, Institute of Plant Science and Resources (IPSR), Okayama University Rice sheath blight, caused by the soil-borne fungus Rhizoctonia solani (teleomorph: Thanatephorus cucumeris, Basidiomycota), is one of the most devastating phytopathogenic fungal diseases and causes yield loss. Here, we report on a very high prevalence (100%) of potential virus-associated double-stranded RNA (dsRNA) elements for a collection of 39 fungal strains of R. solani from the rice sheath blight samples from at least four major rice-growing areas in the Philippines and a reference isolate from the International Rice Research Institute, showing different colony phenotypes. Their dsRNA profiles suggested the presence of multiple viral infections among these Philippine R. solani populations. Using next-generation sequencing, the viral sequences of the three representative R. solani strains (Ilo-Rs-6, Tar-Rs-3, and Tar-Rs-5) from different rice-growing areas revealed the presence of at least 36 viruses or virus-like agents, with the Tar-Rs-3 strain harboring the largest number of viruses (at least 20 in total). These mycoviruses or their candidates are believed to have single-stranded RNA or dsRNA genomes and they belong to or are associated with the orders Martellivirales, Hepelivirales, Durnavirales, Cryppavirales, Ourlivirales, and Ghabrivirales based on their coding-complete RNA-dependent RNA polymerase sequences. The complete genome sequences of two novel RNA viruses belonging to the proposed family Phlegiviridae and family Mitoviridae were determined. No potential conflict of interest relevant to this article was reported.

岡山大学大学院法務研究科 Acta Medica Okayama 1881-1485 26 2025 地域組織と連携した法務系人材育成システム・ 還元ルートの構築・強化 1 30 EN Goro Sato Takamoto Suzuki Tetsuya Ohsaka Takafumi Kobayashi Nobuhiro Okamura Akinari Takehisa 10.18926/OLR/68564 No potential conflict of interest relevant to this article was reported.

American Society for Microbiology Acta Medica Okayama 0022-538X 99 3 2025 A capsidless (+)RNA yadokarivirus hosted by a dsRNA virus is infectious as particles, cDNA, and dsRNA e02166-24 EN Muhammad Fadli Agrivirology Laboratory, Institute of Plant Science and Resources, Okayama University Sakae Hisano Agrivirology Laboratory, Institute of Plant Science and Resources, Okayama University Guy Novoa Department of Structure of Macromolecules, Centro Nacional Biotecnología (CNB-CSIC), Campus de Cantoblanco José R. Castón Department of Structure of Macromolecules, Centro Nacional Biotecnología (CNB-CSIC), Campus de Cantoblanco Hideki Kondo Agrivirology Laboratory, Institute of Plant Science and Resources, Okayama University Nobuhiro Suzuki Agrivirology Laboratory, Institute of Plant Science and Resources, Okayama University Capsidless yadokariviruses (members of the order Yadokarivirales) with (+)RNA genomes divert the capsid of their partner icosahedral double-stranded RNA (dsRNA) viruses in different families of the order Ghabrivirales into the replication site. A yadokarivirus, AfSV2, has been reported from a German strain of the ascomycete fungus Aspergillus foetidus coinfected by two dsRNA viruses, a victorivirus (AfSV1, family Pseudototiviridae) and an alternavirus (AfFV, family Alternaviridae). Here, we identified AfSV1 as the partner of AfSV2 in a Japanese A. foetidus strain after showing the infectiousness of AfSV2 in three forms: virus particles (heterocapsid), transforming full-length complementary DNA (cDNA), and purified replicated form (RF) dsRNA that is believed to be inactive as a translational template. Virion transfection of virus-free A. foetidus protoplasts resulted in the generation of two strains infected either by AfSV1 alone or by both AfSV1 and AfSV2. Transformants with AfSV2 full-length cDNA launched AfSV2 infection only in the presence of AfSV1, but not those with AfSV2 RNA-directed RNA polymerase mutant cDNA. The purified fractions containing AfSV2 RF dsRNA also launched infection when transfected into protoplasts infected by AfSV1. Treatment with dsRNA-specific RNase III, but not with proteinase K, S1 nuclease, or DNase I, abolished the infectivity of AfSV2 RF dsRNA. Furthermore, we confirmed the infectiousness of gel-purified AfSV2 RF dsRNA in the presence of AfSV1. Taken together, our results show the unique infectious entity of AfSV2 and the expansion of yadokarivirus partners in the family Pseudototiviridae and provide interesting evolutionary insights. No potential conflict of interest relevant to this article was reported.

American Society for Microbiology Acta Medica Okayama 2379-5042 9 8 2024 New lineages of RNA viruses from clinical isolates of Rhizopus microsporus revealed by fragmented and primer-ligated dsRNA sequencing (FLDS) analysis EN Wasiatus Sa'diyah Institute of Plant Science and Resources, Okayama University Yan-Jie Zhao Department of Life and Environmental Sciences, Laboratory of Fungal Interaction and Molecular Biology (Donated by IFO), University of Tsukuba Yuto Chiba Department of Life and Environmental Sciences, Laboratory of Fungal Interaction and Molecular Biology (Donated by IFO), University of Tsukuba Hideki Kondo Institute of Plant Science and Resources, Okayama University Nobuhiro Suzuki Institute of Plant Science and Resources, Okayama University Sayaka Ban Medical Mycology Research Center, Chiba University Takashi Yaguchi Medical Mycology Research Center, Chiba University Syun-Ichi Urayama Department of Life and Environmental Sciences, Laboratory of Fungal Interaction and Molecular Biology (Donated by IFO), University of Tsukuba Daisuke Hagiwara Department of Life and Environmental Sciences, Laboratory of Fungal Interaction and Molecular Biology (Donated by IFO), University of Tsukuba Rhizopus microsporus is a species in the order Mucorales that is known to cause mucormycosis, but it is poorly understood as a host of viruses. Here, we examined 25 clinical strains of R. microsporus for viral infection with a conventional double-stranded RNA (dsRNA) assay using agarose gel electrophoresis (AGE) and the recently established fragmented and primer-ligated dsRNA sequencing (FLDS) protocol. By AGE, five virus-infected strains were detected. Then, full-length genomic sequences of 12 novel RNA viruses were revealed by FLDS, which were related to the families Mitoviridae, Narnaviridae, and Endornaviridae, ill-defined groups of single-stranded RNA (ssRNA) viruses with similarity to the established families Virgaviridae and Phasmaviridae, and the proposed family "Ambiguiviridae." All the characterized viruses, except a potential phasmavirid with a negative-sense RNA genome, had positive-sense RNA genomes. One virus belonged to a previously established species within the family Mitoviridae, whereas the other 11 viruses represented new species or even new genera. These results show that the fungal pathogen R. microsporus harbors diverse RNA viruses and extend our understanding of the diversity of RNA viruses in the fungal order Mucorales, division Mucoromycota. Identifying RNA viruses from clinical isolates of R. microsporus may expand the repertoire of natural therapeutic agents for mucormycosis in the future. No potential conflict of interest relevant to this article was reported.

National Academy of Sciences Acta Medica Okayama 0027-8424 121 25 2024 Argonaute-independent, Dicer-dependent antiviral defense against RNA viruses e2322765121 EN Yukiyo Sato Institute of Plant Science and Resources, Okayama University Hideki Kondo Institute of Plant Science and Resources, Okayama University Nobuhiro Suzuki Institute of Plant Science and Resources, Okayama University Antiviral RNA interference (RNAi) is conserved from yeasts to mammals. Dicer recognizes and cleaves virus-derived double-stranded RNA (dsRNA) and/or structured single-stranded RNA (ssRNA) into small-interfering RNAs, which guide effector Argonaute to homologous viral RNAs for digestion and inhibit virus replication. Thus, Argonaute is believed to be essential for antiviral RNAi. Here, we show Argonaute-independent, Dicer-dependent antiviral defense against dsRNA viruses using Cryphonectria parasitica (chestnut blight fungus), which is a model filamentous ascomycetous fungus and hosts a variety of viruses. The fungus has two dicer-like genes (dcl1 and dcl2) and four argonaute-like genes (agl1 to agl4). We prepared a suite of single to quadruple agl knockout mutants with or without dcl disruption. We tested these mutants for antiviral activities against diverse dsRNA viruses and ssRNA viruses. Although both DCL2 and AGL2 worked as antiviral players against some RNA viruses, DCL2 without argonaute was sufficient to block the replication of other RNA viruses. Overall, these results indicate the existence of a Dicer-alone defense and different degrees of susceptibility to it among RNA viruses. We discuss what determines the great difference in susceptibility to the Dicer-only defense. No potential conflict of interest relevant to this article was reported.

National Academy of Sciences Acta Medica Okayama 0027-8424 121 25 2024 Replication of single viruses across the kingdoms, Fungi, Plantae, and Animalia e2318150121 EN Paul Telengech Agrivirology Laboratory, Institute of Plant Science and Resources, Okayama University Kiwamu Hyodo Agrivirology Laboratory, Institute of Plant Science and Resources, Okayama University Hiroaki Ichikawa Institute of Agrobiological Sciences, National Agriculture and Food Research Organization Ryusei Kuwata Faculty of Veterinary Medicine, Okayama University of Science Hideki Kondo Agrivirology Laboratory, Institute of Plant Science and Resources, Okayama University Nobuhiro Suzuki Agrivirology Laboratory, Institute of Plant Science and Resources, Okayama University It is extremely rare that a single virus crosses host barriers across multiple kingdoms. Based on phylogenetic and paleovirological analyses, it has previously been hypothesized that single members of the family Partitiviridae could cross multiple kingdoms. Partitiviridae accommodates members characterized by their simple bisegmented double-stranded RNA genome; asymptomatic infections of host organisms; the absence of an extracellular route for entry in nature; and collectively broad host range. Herein, we show the replicability of single fungal partitiviruses in three kingdoms of host organisms: Fungi, Plantae, and Animalia. Betapartitiviruses of the phytopathogenic fungusRosellinia necatrix could replicate in protoplasts of the carrot (Daucus carota), Nicotiana benthamiana and Nicotiana tabacum, in some cases reaching a level detectable by agarose gel electrophoresis. Moreover, betapartitiviruses showed more robust replication than the tested alphapartitiviruses. One of the fungal betapartitiviruses, RnPV18, could persistently and stably infect carrot plants regenerated from virion-transfected protoplasts. Both alpha- and betapartitiviruses, although with different host preference, could replicate in two insect cell lines derived from the fall armyworm Spodoptera frugiperda and the fruit fly Drosophila melanogaster. Our results indicate the replicability of single partitiviruses in members of three kingdoms and provide insights into virus adaptation, host jumping, and evolution. No potential conflict of interest relevant to this article was reported.

Elsevier Acta Medica Okayama 1369-5274 75 2023 Continued mycovirus discovery expanding our understanding of virus lifestyles, symptom expression, and host defense 102337 EN Yukiyo Sato Institute for Plant Sciences, University of Cologne Nobuhiro Suzuki Institute of Plant Science and Resources, Okayama University High-throughput sequencing technologies have greatly expanded the RNA virome in general and have led to an exponential increase in new fungal viruses, also known as mycoviruses. Mycoviruses are omnipresent in fungi and usually induce symptomless infections. Some mycoviruses infecting fungi pathogenic to plants, insects, and mammals are known to modify host virulence positively and negatively and attract particular interests. In addition, fungal viruses continue to provide intriguing research materials and themes that lead to discoveries of peculiar viruses as infectious entities and insights into virus evolution and diversity. In this review, we outline the diversity and neolifestyle of recently discovered fungal RNA viruses, and phenotypic alterations induced by them. Furthermore, we discuss recent advances in research regarding the fungal antiviral defense and viral counterdefense, which are closely associated with host phenotype alterations. We hope that this article will enhance understanding of the interesting and growing fungal virology field. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0168-1702 334 2023 Exploration of the yadokari/yadonushi nature of YkV3 and RnMBV3 in the original host and a model filamentous fungus 199155 EN Yukiyo Sato Agrivirology Laboratory, Institute of Plant Science and Resources, Okayama University Sakae Hisano Agrivirology Laboratory, Institute of Plant Science and Resources, Okayama University Nobuhiro Suzuki Agrivirology Laboratory, Institute of Plant Science and Resources, Okayama University The yadokari/yadonushi nature is a recently discovered virus lifestyle; “yadokari” refers to the ability of capsidless positive-sense (+) RNA viruses (yadokariviruses) to utilize the capsids of phylogenetically distant double-stranded RNA (dsRNA) viruses possibly as the replication site, while “yadonushi” refers to the ability of dsRNA viruses to provide capsids to yadokariviruses. This virus–virus interaction, however, has been only studied with limited pathosystems. Here, we established a new study model with a capsidless (+)RNA yadokarivirus YkV3 (family Yadokariviridae) and its capsid donor RnMBV3 (family Megabirnaviridae) in the original host fungus Rosellinia necatrix and a model filamentous fungal host Cryphonectria parasitica. YkV3 has a simple genome structure with one open reading frame of 4305 nucleotides encoding a single polyprotein with an RNA-dependent RNA polymerase and a 2A-like self-cleavage peptide domain. Reverse genetics of YkV3 in R. necatrix showed that YkV3 tolerates a nucleotide substitution in the extreme 5′-terminus. The insertion of two termination codons immediately downstream of the 2A-like cleavage site abolished YkV3 viability, suggesting the importance of the C-terminal portion of the polyprotein of unknown function. Transfection of RnMBV3 and YkV3 into an RNA silencing-deficient mutant Δdcl2 of C. parasitica showed the replication competency of both viruses. Comparison between the wild-type and Δdcl2 strains of C. parasitica in virus accumulation suggested that RnMBV3 and YkV3 are susceptible to RNA silencing in C. parasitica. Taken together, we have established a platform to further explore the yadokari/yadonushi nature using genetically manipulable host fungal and virus strains. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 0304-8608 167 12 2022 Identification of novel totiviruses from the ascomycetous fungus Geotrichum candidum 2833 2838 EN Haris Ahmed Khan Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST) Hideki Kondo Institute of Plant Science and Resources (IPSR), Okayama University Sabitree Shahi Institute of Plant Science and Resources (IPSR), Okayama University Muhammad Faraz Bhatti Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST) Nobuhiro Suzuki Institute of Plant Science and Resources (IPSR), Okayama University Mycoviruses are widely distributed across the kingdom Fungi, including ascomycetous yeast strains of the class Saccharomycetes. Geotrichum candidum is an important fungal pathogen belonging to Saccharomycetes and has a diverse host range. Here, we report the characterization of four new classical totiviruses from two distinct Geotrichum candidum strains from Pakistan. The four identified viruses were tentatively named “Geotrichum candidum totivirus 1, 2, 3a, and 3b” (GcTV1-3b). The complete dsRNA genomes of the identified totiviruses are 4621, 4592, 4576, and 4576 bp in length, respectively. All totivirus genomes have two open reading frames, encoding a capsid protein (CP) and an RNA-dependent RNA polymerase (RdRP), respectively. The downstream RdRP domain is assumed to be expressed as a CP-RdRP fusion product via -1 frameshifting mediated by a heptameric slippery site. Sequence comparisons and phylogenetic analysis showed that each of the discovered viruses belongs to a new species of the genus Totivirus in the family Totiviridae, with GcTV1 and GcTV3 (a and b strains) clustering in one subgroup and GcTV2 in another subgroup. No potential conflict of interest relevant to this article was reported.

Public Library of Science Acta Medica Okayama 1553-7366 19 2 2023 Capsid structure of a fungal dsRNA megabirnavirus reveals its previously unidentified surface architecture e1011162 EN Han Wang The Laboratory of Molecular Biophysics, Department of Cell and Molecular Biology, Uppsala University Lakha Salaipeth Institute of Plant Science and Resources, Okayama University Naoyuki Miyazaki Life Science Center of Survival Dynamics, Tsukuba Advanced Research Alliance, University of Tsukuba Nobuhiro Suzuki Institute of Plant Science and Resources, Okayama University Kenta Okamoto The Laboratory of Molecular Biophysics, Department of Cell and Molecular Biology, Uppsala University Rosellinia necatrix megabirnavirus 1-W779 (RnMBV1) is a non-enveloped icosahedral double-stranded (ds)RNA virus that infects the ascomycete fungus Rosellinia necatrix, a causative agent that induces a lethal plant disease white root rot. Herein, we have first resolved the atomic structure of the RnMBV1 capsid at 3.2 angstrom resolution using cryo-electron microscopy (cryo-EM) single-particle analysis. Compared with other non-enveloped icosahedral dsRNA viruses, the RnMBV1 capsid protein structure exhibits an extra-long C-terminal arm and a surface protrusion domain. In addition, the previously unrecognized crown proteins are identified in a symmetry-expanded cryo-EM model and are present over the 3-fold axes. These exclusive structural features of the RnMBV1 capsid could have been acquired for playing essential roles in transmission and/or particle assembly of the megabirnaviruses. Our findings, therefore, will reinforce the understanding of how the structural and molecular machineries of the megabirnaviruses influence the virulence of the disease-related ascomycete fungus. Author summaryA fungal plant soil-borne pathogen, Rosellinia necatrix, which can cause devastating disease white root rot in many highly valued fruit trees, is difficult to be controlled with conventional approaches such as fungicide applications. Rosellinia necatrix megabirnavirus 1-W779 (RnMBV1) is a dsRNA virus isolated from the R. necatrix field strain, W779, and this virus can be a viro-control candidate to confer hypovirulence in its host R. necatrix. To make use of RnMBV1 in the white root rot disease control, more molecular and structural investigations will offer us more insights. Here, we have performed cryo-electron microscopy (cryo-EM) single-particle analysis, to obtain the first atomic models of RnMBV1 particles. Based on the atomic structures, we found unique both surface and interior features. In addition, we found a previously unidentified protein on the viral surface. These aforementioned structural features might play important roles in the viral life cycles, and will enable us to apply this fungal virus as a viro-control approach. No potential conflict of interest relevant to this article was reported.

American Society for Microbiology Acta Medica Okayama 2150-7511 2022 Three-Layered Complex Interactions among Capsidless (+)ssRNA Yadokariviruses, dsRNA Viruses, and a Fungus EN Yukiyo Sato Agrivirology Laboratory, Institute of Plant Science and Resources, Okayama University Sakae Hisano Agrivirology Laboratory, Institute of Plant Science and Resources, Okayama University Carlos Jose Lopez-Herrera Instituto de Agricultura Sostenible C.S.I.C., Alameda del Obispo Hideki Kondo Agrivirology Laboratory, Institute of Plant Science and Resources, Okayama University Nobuhiro Suzuki Agrivirology Laboratory, Institute of Plant Science and Resources, Okayama University We have previously discovered a virus neo-lifestyle exhibited by a capsidless positive-sense (+), single-stranded (ss) RNA virus YkV1 (family Yadokariviridae) and an unrelated double-stranded (ds) RNA virus YnV1 (proposed family "Yadonushiviridae") in a phytopathogenic ascomycete, Rosellinia necatrix. YkV1 has been proposed to replicate in the capsid provided by YnV1 as if it were a dsRNA virus and enhance YnV1 replication in return. Recently, viruses related to YkV1 (yadokariviruses) have been isolated from diverse ascomycetous fungi. However, it remains obscure whether such viruses generally show the YkV1-like lifestyle. Here, we identified partner viruses for three distinct yadokariviruses, YkV3, YkV4a, and YkV4b, isolated from R. necatrix that were coinfected with multiple dsRNA viruses phylogenetically distantly related to YnV1. We first established transformants of R. necatrix carrying single yadokarivirus cDNAs and fused them with infectants by single partner candidate dsRNA viruses. Consequently, YkV3 and YkV4s replicated only in the presence of RnMBV3 (family Megabirnaviridae) and RnMTV1 (proposed family "Megatotiviridae"), respectively. The partners were mutually interchangeable between the two YkV4 strains and three RnMTV1 strains but not between other combinations involving YkV1 or YkV3. In contrast to YkV1 enhancing YnV1 accumulation, YkV4s reduced RnMTV1 accumulation to different degrees according to strains. Interestingly, YkV4 rescued the host R. necatrix from impaired growth induced by RnMTV1. YkV3 exerted no apparent effect on its partner (RnMBV3) or host fungus. Overall, we revealed that while yadokariviruses generally require partner dsRNA viruses for replication, each yadokarivirus partners with a different dsRNA virus species in the three diverse families and shows a distinct symbiotic relation in a fungus. IMPORTANCE A capsidless (+)ssRNA virus YkV1 (family Yadokariviridae) highjacks the capsid of an unrelated dsRNA virus YnV1 (proposed family "Yadonushiviridae") in a phytopathogenic ascomycete, while YkV1 trans-enhances YnV1 replication. Herein, we identified the dsRNA virus partners of three yadokariviruses (YkV3, YkV4a, and YkV4b) with genome organization different from YkV1 as being different from YnV1 at the suborder level. Their partners were mutually interchangeable between the two YkV4 strains and three strains of the partner virus RnMTV1 (proposed family "Megatotiviridae") but not between other combinations involving YkV1 or YkV3. Unlike YkV1, YkV4s reduced RnMTV1 accumulation and rescued the host fungus from impaired growth induced by RnMTV1. YkV3 exerted no apparent effect on its partner (RnMBV3, family Megabirnaviridae) or host fungus. These revealed that while each yadokarivirus has a species-specific partnership with a dsRNA virus, yadokariviruses collectively partner extremely diverse dsRNA viruses and show three-layered complex mutualistic/antagonistic interactions in a fungus. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 1999-4915 14 8 2022 A Transfectable Fusagravirus from a Japanese Strain of Cryphonectria carpinicola with Spherical Particles 1722 EN Subha Das Institute of Plant Science and Resources, Okayama University Sakae Hisano Institute of Plant Science and Resources, Okayama University Ana Eusebio-Cope Institute of Plant Science and Resources, Okayama University Hideki Kondo Institute of Plant Science and Resources, Okayama University Nobuhiro Suzuki Institute of Plant Science and Resources, Okayama University A novel dsRNA virus (Cryphonectria carpinicola fusagravirus 1, CcFGV1), isolated from a Japanese strain (JS13) of Cryphonectria carpinicola, was thoroughly characterized. The biological comparison of a set of isogenic CcFGV1-infected and -free (JS13VF) strains indicated asymptomatic infection by CcFGV1. The sequence analysis showed that the virus has a two open reading frame (ORF) genome of 9.6 kbp with the RNA-directed RNA polymerase domain encoded by ORF2. The N-terminal sequencing and peptide mass fingerprinting showed an N-terminally processed or degraded product (150 kDa) of the 5'-proximal ORF1-encoded protein (1462 amino acids) to make up the CcFGV1 spherical particles of similar to 40 nm in diameter. Interestingly, a portion of CcFGV1 dsRNA co-fractionated with a host protein of 70 kDa. The purified CcFGV1 particles were used to transfect protoplasts of JS13VF as well as the standard strain of an experimental model filamentous fungal host Cryphonectria parasitica. CcFGV1 was confirmed to be associated with asymptomatic infection of both fungi. RNA silencing was shown to target the virus in C. parasitica, resulting in reduced CcFGV1 accumulation by comparing the CcFGV1 content between RNA silencing-competent and -deficient strains. These results indicate the transfectability of spherical particles of a fusagravirus associated with asymptomatic infection. No potential conflict of interest relevant to this article was reported.

FRONTIERS MEDIA SA Acta Medica Okayama 2235-2988 12 2022 Mycovirus Hunting Revealed the Presence of Diverse Viruses in a Single Isolate of the Phytopathogenic Fungus Diplodia seriata From Pakistan 913619 EN Haris Ahmed Khan Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST) Paul Telengech Institute of Plant Science and Resources, Okayama University Hideki Kondo Institute of Plant Science and Resources, Okayama University Muhammad Faraz Bhatti Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST) Nobuhiro Suzuki Institute of Plant Science and Resources, Okayama University Diplodia seriata in the family Botryosphaeriaceae is a cosmopolitan phytopathogenic fungus and is responsible for causing cankers, fruit rot and leaf spots on economically important plants. In this study, we characterized the virome of a single Pakistani strain (L3) of D. seriata. Several viral-like contig sequences were obtained via a previously conducted next-generation sequencing analysis. Multiple infection of the L3 strain by eight RNA mycoviruses was confirmed through RT-PCR using total RNA samples extracted from this strain; the entire genomes were determined via Sanger sequencing of RT-PCR and RACE clones. A BLAST search and phylogenetic analyses indicated that these eight mycoviruses belong to seven different viral families. Four identified mycoviruses belong to double-stranded RNA viral families, including Polymycoviridae, Chrysoviridae, Totiviridae and Partitiviridae, and the remaining four identified mycoviruses belong to single-stranded RNA viral families, i.e., Botourmiaviridae, and two previously proposed families "Ambiguiviridae" and "Splipalmiviridae". Of the eight, five mycoviruses appear to represent new virus species. A morphological comparison of L3 and partially cured strain L3ht1 suggested that one or more of the three viruses belonging to Polymycoviridae, "Splipalmiviridae" and "Ambiguiviridae" are involved in the irregular colony phenotype of L3. To our knowledge, this is the first report of diverse virome characterization from D. seriata. No potential conflict of interest relevant to this article was reported.

Elsevier BV Acta Medica Okayama 0168-1702 307 2 2022 A new tetra-segmented splipalmivirus with divided RdRP domains from Cryphonectria naterciae, a fungus found on chestnut and cork oak trees in Europe 198606 EN Yukiyo Sato Institute of Plant Science and Resources, Okayama University Sabitree Shahi Institute of Plant Science and Resources, Okayama University Paul Telengech Institute of Plant Science and Resources, Okayama University Sakae Hisano Institute of Plant Science and Resources, Okayama University Carolina Cornejo Swiss Federal Research Institute WSL, Forest Health & Biotic Interactions Daniel Rigling Swiss Federal Research Institute WSL, Forest Health & Biotic Interactions Hideki Kondo Institute of Plant Science and Resources, Okayama University Nobuhiro Suzuki Institute of Plant Science and Resources, Okayama University Positive-sense (+), single-stranded (ss) RNA viruses with divided RNA-dependent RNA polymerase (RdRP) domains have been reported from diverse filamentous ascomycetes since 2020. These viruses are termed splipalmiviruses or polynarnaviruses and have been characterized largely at the sequence level, but ill-defined biologically. Cryphonectria naterciae, from which only one virus has been reported, is an ascomycetous fungus potentially plant-pathogenic to chestnut and oak trees. We molecularly characterized multiple viruses in a single Portuguese isolate (C0614) of C. naterciae, taking a metatranscriptomic and conventional double-stranded RNA approach. Among them are a novel splipalmivirus (Cryphonectria naterciae splipalmivirus 1, CnSpV1) and a novel fusagravirus (Cryphonectria naterciae fusagravirus 1, CnFGV1). This study focused on the former virus. CnSpV1 has a tetra-segmented, (+)ssRNA genome (RNA1 to RNA4). As observed for other splipalmiviruses reported in 2020 and 2021, the RdRP domain is separately encoded by RNA1 (motifs F, A and B) and RNA2 (motifs C and D). A hypothetical protein encoded by the 5′-proximal open reading frame of RNA3 shows similarity to a counterpart conserved in some splipalmiviruses. The other RNA3-encoded protein and RNA4-encoded protein show no similarity with known proteins in a blastp search. The tetra-segment nature was confirmed by the conserved terminal sequences of the four CnSpV1 segments (RNA1 to RNA4) and their 100% coexistence in over 100 single conidial isolates tested. The experimental introduction of CnSpV1 along with CnFGV1 into a virus free strain C0754 of C. naterciae vegetatively incompatible with C0614 resulted in no phenotypic alteration, suggesting asymptomatic infection. The protoplast fusion assay indicates a considerably narrow host range of CnSpV1, restricted to the species C. naterciae and C. carpinicola. This study contributes to better understanding of the molecular and biological properties of this unique group of viruses. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 0304-8608 167 4 2022 A novel deltapartitivirus from red clover 1201 1204 EN Paul Telengech Institute of Plant Science and Resources, Okayama University Sabitree Shahi Institute of Plant Science and Resources, Okayama University Hideki Kondo Institute of Plant Science and Resources, Okayama University Nobuhiro Suzuki Institute of Plant Science and Resources, Okayama University The family Partitiviridae has five genera, among which is the genus Deltapartitivirus. We report here the complete genome sequence of a deltapartitivirus from red clover, termed “red clover cryptic virus 3” (RCCV3). RCCV3 has a bisegmented double-stranded (ds) RNA genome. dsRNA1 and dsRNA2 are 1580 and 1589 nucleotides (nt) in length and are predicted to encode an RNA-directed RNA polymerase (RdRP) and a capsid protein (CP), respectively. The RCCV3 RdRP shares the highest sequence identity with the RdRP of a previously reported deltapartitivirus, Medicago sativa deltapartitivirus 1 (MsDPV1) (76.5%), while the RCCV3 CP shows 50% sequence identity to the CP of MsDPV1. RdRP- and CP-based phylogenetic trees place RCCV3 into a clade of deltapartitiviruses. The sequence and phylogenetic analyses clearly indicate that RCCV3 represents a new species in the genus Deltapartitivirus. RCCV3 was detectable in all three tested cultivars of red clover. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 0304-8608 167 2022 A novel victorivirus from the phytopathogenic fungus Neofusicoccum parvum 923 929 EN Haris Ahmed Khan Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST) Yukiyo Sato Institute of Plant Science and Resources, Okayama University Hideki Kondo Institute of Plant Science and Resources, Okayama University Atif Jamal Crop Diseases Research Institute, National Agricultural Research Centre Muhammad Faraz Bhatti Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST) Nobuhiro Suzuki Institute of Plant Science and Resources, Okayama University Neofusicoccum parvum is an important plant-pathogenic ascomycetous fungus that causes trunk diseases in a variety of plants. A limited number of reports on mycoviruses from this fungus are available. Here, we report the characterization of a novel victorivirus, Neofusicoccum parvum victorivirus 3 (NpVV3). An agarose gel dsRNA profile of a Pakistani strain of N. parvum, NFN, showed a band of similar to 5 kbp that was not detectable in Japanese strains of N. parvum. Taking a high-throughput and Sanger sequencing approach, the complete genome sequence of NpVV3 was determined to be 5226 bp in length with two open reading frames (ORF1 and ORF2) that encode a capsid protein (CP) and an RNA-dependent RNA polymerase (RdRP). The RdRP appears to be translated by a stop/restart mechanism facilitated by the junction sequence AUGucUGA, as is found in some other victoriviruses. BLASTp searches showed that NpVV3 CP and RdRP share the highest amino acid sequence identity (80.5% and 72.4%, respectively) with the corresponding proteins of NpVV1 isolated from a French strain of N. parvum. However, NpVV3 was found to be different from NpVV1 in its terminal sequences and the stop/restart facilitator sequence. NpVV3 particles similar to 35 nm in diameter were partially purified and used to infect an antiviral-RNA-silencing-deficient strain (Delta cl2) of an experimental ascomycetous fungal host, Cryphonectria parasitica. NpVV3 showed symptomless infection in the new host strain. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 1345-2630 88 2 2022 Plant viruses and viroids in Japan 105 127 EN Shin-ichi Fuji Faculty of Bioresource Sciences, Akita Prefectural University Tomofumi Mochizuki Graduate School of Life and Environmental Sciences, Osaka Prefecture University Mitsuru Okuda Office of the President, National Agriculture and Food Research Organization (NARO) Shinya Tsuda Department of Clinical Plant Science, Faculty of Bioscience and Applied Chemistry Satoshi Kagiwada Department of Clinical Plant Science, Faculty of Bioscience and Applied Chemistry, Hosei University Ken-Taro Sekine Faculty of Agriculture, University of the Ryukyus Masashi Ugaki Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo Keiko T. Natsuaki Tokyo University of Agriculture Masamichi Isogai Faculty of Agriculture, Iwate University Tetsuo Maoka Institute for Plant Protection, National Agriculture and Food Research Organization (NIPP, NARO) Minoru Takeshita Department of Agricultural and Environmental Sciences, Faculty of Agriculture, University of Miyazak Nobuyuki Yoshikawa Agri-Innovation Center, Iwate University Kazuyuki Mise Graduate School of Agriculture, Kyoto University Takahide Sasaya 3 Department of Research Promotion, Institute for Plant Protection, National Agriculture and Food Research Organization (NIPP, NARO) Hideki Kondo Group of Plant-Microbe Interactions, Institute of Plant Science and Resources, Okayama University Kenji Kubota Division of Core Technology for Pest Control Research, Institute for Plant Protection, National Agriculture and Food Research Organization (NIPP, NARO) Yasuyuki Yamaji Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo Toru Iwanami Faculty of Agriculture, Tokyo University of Agriculture Kazusato Ohshima Department of Biological Resource Science, Faculty of Agriculture, Saga University Kappei Kobayashi Faculty of Agriculture, Ehime University Tatsuji Hataya Research Faculty of Agriculture, Hokkaido University Teruo Sano Hirosaki University Nobuhiro Suzuki Group of Plant-Microbe Interactions, Institute of Plant Science and Resources, Okayama University An increasing number of plant viruses and viroids have been reported from all over the world due largely to metavirogenomics approaches with technological innovation. Herein, the official changes of virus taxonomy, including the establishment of megataxonomy and amendments of the codes of virus classification and nomenclature, recently made by the International Committee on Taxonomy of Viruses were summarized. The continued efforts of the plant virology community of Japan to index all plant viruses and viroids occurring in Japan, which represent 407 viruses, including 303 virus species and 104 unclassified viruses, and 25 viroids, including 20 species and 5 unclassified viroids, as of October 2021, were also introduced. These viruses and viroids are collectively classified into 81 genera within 26 families of 3 kingdoms (Shotokuvirae, Orthornavirae, Pararnavirae) across 2 realms (Monodnaviria and Riboviria). This review also overviewed how Japan’s plant virus/viroid studies have contributed to advance virus/viroid taxonomy. No potential conflict of interest relevant to this article was reported.

American Society for Microbiology Acta Medica Okayama 0022-538X 95 17 2021 Proof of Concept of the Yadokari Nature: a Capsidless Replicase-Encoding but Replication-Dependent Positive-Sense Single-Stranded RNA Virus Hosted by an Unrelated Double-Stranded RNA Virus e00467-21 EN Subha Das Agrivirology Laboratory, Institute of Plant Science and Resources, Okayama University Md Mahfuz Alam Agrivirology Laboratory, Institute of Plant Science and Resources, Okayama University Rui Zhang Agrivirology Laboratory, Institute of Plant Science and Resources, Okayama University Sakae Hisano Agrivirology Laboratory, Institute of Plant Science and Resources, Okayama University Nobuhiro Suzuki Agrivirology Laboratory, Institute of Plant Science and Resources, Okayama University Viruses typically encode their own capsids that encase their genomes. However, a capsidless positive-sense single stranded RNA [(+)ssRNA] virus, YkV1, depends on an unrelated double-stranded RNA (dsRNA) virus, YnV1, for encapsidation and replication. No potential conflict of interest relevant to this article was reported.

Frontiers Media SA Acta Medica Okayama 1664-302X 12 2021 Identification of a Novel Quinvirus in the Family Betaflexiviridae That Infects Winter Wheat 715545 EN Hideki Kondo Institute of Plant Science and Resources (IPSR), Okayama University Naoto Yoshida Agricultural Research Institute, HOKUREN Federation of Agricultural Cooperatives Miki Fujita Institute of Plant Science and Resources (IPSR), Okayama University Kazuyuki Maruyama Institute of Plant Science and Resources (IPSR), Okayama University Kiwamu Hyodo Institute of Plant Science and Resources (IPSR), Okayama University Hiroshi Hisano Institute of Plant Science and Resources (IPSR), Okayama University Tetsuo Tamada Institute of Plant Science and Resources (IPSR), Okayama University Ida Bagus Andika College of Plant Health and Medicine, Qingdao Agricultural University Nobuhiro Suzuki Institute of Plant Science and Resources (IPSR), Okayama University Yellow mosaic disease in winter wheat is usually attributed to the infection by bymoviruses or furoviruses; however, there is still limited information on whether other viral agents are also associated with this disease. To investigate the wheat viromes associated with yellow mosaic disease, we carried out de novo RNA sequencing (RNA-seq) analyses of symptomatic and asymptomatic wheat-leaf samples obtained from a field in Hokkaido, Japan, in 2018 and 2019. The analyses revealed the infection by a novel betaflexivirus, which tentatively named wheat virus Q (WVQ), together with wheat yellow mosaic virus (WYMV, a bymovirus) and northern cereal mosaic virus (a cytorhabdovirus). Basic local alignment search tool (BLAST) analyses showed that the WVQ strains (of which there are at least three) were related to the members of the genus Foveavirus in the subfamily Quinvirinae (family Betaflexiviridae). In the phylogenetic tree, they form a clade distant from that of the foveaviruses, suggesting that WVQ is a member of a novel genus in the Quinvirinae. Laboratory tests confirmed that WVQ, like WYMV, is potentially transmitted through the soil to wheat plants. WVQ was also found to infect rye plants grown in the same field. Moreover, WVQ-derived small interfering RNAs accumulated in the infected wheat plants, indicating that WVQ infection induces antiviral RNA silencing responses. Given its common coexistence with WYMV, the impact of WVQ infection on yellow mosaic disease in the field warrants detailed investigation. No potential conflict of interest relevant to this article was reported.

Springer Science and Business Media LLC Acta Medica Okayama 0304-8608 166 2021 A second capsidless hadakavirus strain with 10 positive-sense single-stranded RNA genomic segments from Fusarium nygamai 2711 2722 EN Haris Ahmed Khan Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST) Yukiyo Sato Institute of Plant Science and Resources, Okayama University Hideki Kondo Institute of Plant Science and Resources, Okayama University Atif Jamal Crop Diseases Research Institute, National Agricultural Research Centre Muhammad Faraz Bhatti Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST) Nobuhiro Suzuki Institute of Plant Science and Resources, Okayama University A unique capsidless virus with a positive-sense, single-stranded RNA genome (hadakavirus 1, HadV1), a member of the extended picorna-like supergroup, was isolated previously from the phytopathogenic fungus Fusarium oxysporum. Here, we describe the molecular and biological characterisation of a second hadakavirus strain from Fusarium nygamai, which has not been investigated in detail previously as a virus host. This virus, hadakavirus 1 strain 1NL (HadV1-1NL), has features similar to the first hadakavirus, HadV1-7n, despite having a different number of segments (10 for HadV1-1NL vs. 11 for HadV1-7n). The 10 genomic RNA segments of HadV1-1NL range in size from 0.9 kb to 2.5 kb. All HadV1-1NL segments show 67% to 86% local nucleotide sequence identity to their HadV1-7n counterparts, whereas HadV1-1NL has no homolog of HadV1-7n RNA8, which encodes a zinc-finger motif. Another interesting feature is the possible coding incapability of HadV1-1NL RNA10. HadV1-1NL was predicted to be capsidless based on the RNase A susceptibility of its replicative form dsRNA. Phenotypic comparison of multiple virus-infected and virus-free single-spore isolates indicated asymptomatic infection by HadV1-1NL. Less-efficient vertical transmission via spores was observed as the infected fungal colonies from which the spores were derived became older, as was observed for HadV1-7n. This study shows a second example of a hadakavirus that appears to have unusual features. No potential conflict of interest relevant to this article was reported.

MDPI Acta Medica Okayama 2079-7737 10 2 2021 Identification of an RNA Silencing Suppressor Encoded by a Symptomless Fungal Hypovirus, Cryphonectria Hypovirus 4 100 EN Annisa Aulia Institute of Plant Science and Resources (IPSR), Okayama University Kiwamu Hyodo Institute of Plant Science and Resources (IPSR), Okayama University Sakae Hisano Institute of Plant Science and Resources (IPSR), Okayama University Hideki Kondo Institute of Plant Science and Resources (IPSR), Okayama University Bradley I. Hillman Plant Biology and Pathology, Rutgers University Nobuhiro Suzuki Institute of Plant Science and Resources (IPSR), Okayama University Previously, we have reported the ability of a symptomless hypovirus Cryphonectria hypovirus 4 (CHV4) of the chestnut blight fungus to facilitate stable infection by a co-infecting mycoreovirus 2 (MyRV2)—likely through the inhibitory effect of CHV4 on RNA silencing (Aulia et al., Virology, 2019). In this study, the N-terminal portion of the CHV4 polyprotein, termed p24, is identified as an autocatalytic protease capable of suppressing host antiviral RNA silencing. Using a bacterial expression system, CHV4 p24 is shown to cleave autocatalytically at the di-glycine peptide (Gly214-Gly215) of the polyprotein through its protease activity. Transgenic expression of CHV4 p24 in Cryphonectria parasitica suppresses the induction of one of the key genes of the antiviral RNA silencing, dicer-like 2, and stabilizes the infection of RNA silencing-susceptible virus MyRV2. This study shows functional similarity between CHV4 p24 and its homolog p29, encoded by the symptomatic prototype hypovirus CHV1. No potential conflict of interest relevant to this article was reported.

Elsevier Acta Medica Okayama 0042-6822 554 2021 Cryphonectria nitschkei chrysovirus 1 with unique molecular features and a very narrow host range 55 62 EN Sabitree Shahi Institute of Plant Science and Resources, Okayama University Sotaro Chiba Graduate School of Bioagricultural Sciences, Nagoya University Hideki Kondo Institute of Plant Science and Resources, Okayama University Nobuhiro Suzuki Institute of Plant Science and Resources, Okayama University Cryphonectria nitschkei chrysovirus 1 (CnCV1), was described earlier from an ascomycetous fungus, Cryphonectria nitschkei strain OB5/11, collected in Japan; its partial sequence was reported a decade ago. Complete sequencing of the four genomic dsRNA segments revealed molecular features similar to but distinct from previously reported members of the family Chrysoviridae. Unique features include the presence of a mini-cistron preceding the major large open reading frame in each genomic segment. Common features include the presence of CAA repeats in the 5′-untranslated regions and conserved terminal sequences. CnCV1-OB5/11 could be laterally transferred to C. nitschkei and its relatives C. radicalis and C. naterciae via coculturing, virion transfection and protoplast fusion, but not to fungal species other than the three species mentioned above, even within the genus Cryphonectria, suggesting a very narrow host range. Phenotypic comparison of a few sets of CnCV1-infected and -free isogenic strains showed symptomless infection in new hosts. No potential conflict of interest relevant to this article was reported.

Nature Research Acta Medica Okayama 2041-1723 11 1 2020 Establishment of Neurospora crassa as a model organism for fungal virology 5627 EN Shinji Honda Faculty of Medical Sciences, University of Fukui Ana Eusebio-Cope Institute of Plant Science and Resources, Okayama University Shuhei Miyashita Graduate School of Agricultural Science, Tohoku University Ayumi Yokoyama Faculty of Medical Sciences, University of Fukui Annisa Aulia Institute of Plant Science and Resources, Okayama University Sabitree Shahi Institute of Plant Science and Resources, Okayama University Hideki Kondo Institute of Plant Science and Resources, Okayama University Nobuhiro Suzuki Institute of Plant Science and Resources, Okayama University The filamentous fungus Neurospora crassa is used as a model organism for genetics, developmental biology and molecular biology. Remarkably, it is not known to host or to be susceptible to infection with any viruses. Here, we identify diverse RNA viruses in N. crassa and other Neurospora species, and show that N. crassa supports the replication of these viruses as well as some viruses from other fungi. Several encapsidated double-stranded RNA viruses and capsid-less positive-sense single-stranded RNA viruses can be experimentally introduced into N. crassa protoplasts or spheroplasts. This allowed us to examine viral replication and RNAi-mediated antiviral responses in this organism. We show that viral infection upregulates the transcription of RNAi components, and that Dicer proteins (DCL-1, DCL-2) and an Argonaute (QDE-2) participate in suppression of viral replication. Our study thus establishes N. crassa as a model system for the study of host-virus interactions. The fungus Neurospora crassa is a model organism for the study of various biological processes, but it is not known to be infected by any viruses. Here, Honda et al. identify RNA viruses that infect N. crassa and examine viral replication and RNAi-mediated antiviral responses, thus establishing this fungus as a model for the study of host-virus interactions. No potential conflict of interest relevant to this article was reported.

Frontiers Media Acta Medica Okayama 1664-302X 11 2020 Molecular Characterization of a Novel Polymycovirus From Penicillium janthinellum With a Focus on Its Genome-Associated PASrp 592789 EN Yukiyo Sato Institute of Plant Science and Resources, Okayama University Atif Jamal Crop Diseases Research Institute, National Agricultural Research Centre Hideki Kondo Institute of Plant Science and Resources, Okayama University Nobuhiro Suzuki Institute of Plant Science and Resources, Okayama University The genus Polymycovirus of the family Polymycoviridae accommodates fungal RNA viruses with different genomic segment numbers (four, five, or eight). It is suggested that four members form no true capsids and one forms filamentous virus particles enclosing double-stranded RNA (dsRNA). In both cases, viral dsRNA is associated with a viral protein termed "proline-alanine-serine-rich protein" (PASrp). These forms are assumed to be the infectious entity. However, the detailed molecular characteristics of PASrps remain unclear. Here, we identified a novel five-segmented polymycovirus, Penicillium janthinellum polymycovirus 1 (PjPmV1), and characterized its purified fraction form in detail. The PjPmV1 had five dsRNA segments associated with PASrp. Density gradient ultracentrifugation of the PASrp-associated PjPmV1 dsRNA revealed its uneven structure and a broad fractionation profile distinct from that of typical encapsidated viruses. Moreover, PjPmV1-PASrp interacted in vitro with various nucleic acids in a sequence-non-specific manner. These PjPmV1 features are discussed in view of the diversification of genomic segment numbers of the genus Polymycovirus. No potential conflict of interest relevant to this article was reported.

Elsevier Acta Medica Okayama 0168-1702 244 2018 A neo-virus lifestyle exhibited by a (+)ssRNA virus hosted in an unrelated dsRNA virus: Taxonomic and evolutionary considerations 75 83 EN Sakae Hisano Institute of Plant Science and Resources (IPSR), Okayama University Rui Zhang Institute of Plant Science and Resources (IPSR), Okayama University Md. Iqbal Faruk Institute of Plant Science and Resources (IPSR), Okayama University Hideki Kondo Institute of Plant Science and Resources (IPSR), Okayama University Nobuhiro Suzuki Institute of Plant Science and Resources (IPSR), Okayama University Recent studies illustrate that fungi as virus hosts provides a unique platform for hunting viruses and exploring virus/virus and virus/host interactions. Such studies have revealed a number of as-yet-unreported viruses and virus/virus interactions. Among them is a unique intimate relationship between a (+)ssRNA virus, yado-kari virus (YkV1) and an unrelated dsRNA virus, yado-nushi virus (YnV1). YkV1 dsRNA, a replicated form of YkV1, and RNA-dependent RNA polymerase, are trans-encapsidated by the capsid protein of YnV1. While YnV1 can complete its replication cycle, YkV1 relies on YnV1 for its viability. We previously proposed a model in which YkV1 diverts YnV1 capsids as the replication sites. YkV1 is neither satellite virus nor satellite RNA, because YkV1 appears to encode functional RdRp and enhances YnV1 accumulation. This represents a unique mutualistic virus/virus interplay and similar relations in other virus/host fungus systems are detectable. We propose to establish the family Yadokariviridae that accommodates YkV1 and recently discovered viruses phylogenetically related to YkV1. This article overviews what is known and unknown about the YkV1/YnV1 interactions. Also discussed are the YnV1 Phytoreo_S7 and YkV1 2A-like domains that may have been captured via horizontal transfer during the course of evolution and are conserved across extant diverse RNA viruses. Lastly, evolutionary scenarios are envisioned for YkV1 and YnV1. No potential conflict of interest relevant to this article was reported.

Nature Research Acta Medica Okayama 2058-5276 1 1 2016 A capsidless ssRNA virus hosted by an unrelated dsRNA virus 15001 EN Rui Zhang Agrivirology Laboratory, Institute of Plant Science and Resources, Okayama University Sakae Hisano Agrivirology Laboratory, Institute of Plant Science and Resources, Okayama University Akio Tani Agrivirology Laboratory, Institute of Plant Science and Resources, Okayama University Hideki Kondo Agrivirology Laboratory, Institute of Plant Science and Resources, Okayama University Satoko Kanematsu NARO Institute of Fruit Tree Science Nobuhiro Suzuki Agrivirology Laboratory, Institute of Plant Science and Resources, Okayama University Viruses typically encode the capsid that encases their genome, while satellite viruses do not encode a replicase and depend on a helper virus for their replication1. Here, we report interplay between two RNA viruses, yado-nushi virus 1 (YnV1) and yado-kari virus 1 (YkV1), in a phytopathogenic fungus, Rosellinia necatrix2. YkV1 has a close phylogenetic affinity to positive-sense, single-stranded (+)ssRNA viruses such as animal caliciviruses3, while YnV1 has an undivided double-stranded (ds) RNA genome with a resemblance to fungal totiviruses4. Virion transfection and infectious full-length cDNA transformation has shown that YkV1 depends on YnV1 for viability, although it probably encodes functional RNA-dependent RNA polymerase (RdRp). Immunological and molecular analyses have revealed trans-encapsidation of not only YkV1 RNA but also RdRp by the capsid protein of the other virus (YnV1), and enhancement of YnV1 accumulation by YkV1. This study demonstrates interplay in which the capsidless (+)ssRNA virus (YkV1), hijacks the capsid protein of the dsRNA virus (YnV1), and replicates as if it were a dsRNA virus. No potential conflict of interest relevant to this article was reported.

American Society for Microbiology Acta Medica Okayama 2150-7511 11 3 2020 Hadaka Virus 1: a Capsidless Eleven-Segmented Positive-Sense Single-Stranded RNA Virus from a Phytopathogenic Fungus, Fusarium oxysporum e00450-20 EN Yukiyo Sato Institute of Plant Science and Resources, Okayama University Wajeeha Shamsi Institute of Plant Science and Resources, Okayama University Atif Jamal Crop Diseases Research Institute, National Agricultural Research Centre Muhammad Faraz Bhatti Atta-ur-Rahman School of Applied Biosciences (ASAB), National University of Sciences and Technology (NUST) Hideki Kondo Institute of Plant Science and Resources, Okayama University Nobuhiro Suzuki Institute of Plant Science and Resources, Okayama University The search for viruses infecting fungi, or mycoviruses, has extended our knowledge about the diversity of RNA viruses, as exemplified by the discovery of polymycoviruses, a phylogenetic group of multisegmented RNA viruses with unusual forms. The genomic RNAs of known polymycoviruses, which show a phylogenetic affinity for animal positive-sense single-stranded RNA [(+)RNA] viruses such as caliciviruses, are comprised of four conserved segments with an additional zero to four segments. The double-stranded form of polymycovirus genomic RNA is assumed to be associated with a virally encoded protein (proline-alanine-serine-rich protein [PASrp]) in either of two manners: a capsidless colloidal form or a filamentous encapsidated form. Detailed molecular characterizations of polymycoviruses, however, have been conducted for only a few strains. Here, a novel polymyco-related virus named Hadaka virus 1 (HadV1), from the phytopathogenic fungus Fusarium oxysporum, was characterized. The genomic RNA of HadV1 consisted of an 11-segmented positive-sense RNA with highly conserved terminal nucleotide sequences. HadV1 shared the three conserved segments with known polymycoviruses but lacked the PASrp-encoding segment. Unlike the known polymycoviruses and encapsidated viruses, HadV1 was not pelleted by conventional ultracentrifugation, possibly due to the lack of PASrp. This result implied that HadV1 exists only as a soluble form with naked RNA. Nevertheless, the 11 genomic segments of HadV1 have been stably maintained through host subculturing and conidiation. Taken together, the results of this study revealed a virus with a potential novel virus lifestyle, carrying many genomic segments without typical capsids or PASrp-associated forms. IMPORTANCE Fungi collectively host various RNA viruses. Examples include encapsidated double-stranded RNA (dsRNA) viruses with diverse numbers of genomic segments (from 1 to 12) and capsidless viruses with nonsegmented (+)RNA genomes. Recently, viruses with unusual intermediate features of an infectious entity between encapsidated dsRNA viruses and capsidless (+)RNA viruses were found. They are called polymycoviruses, which typically have four to eight dsRNA genomic segments associated with one of the virus-encoded proteins and are phylogenetically distantly related to animal (+)RNA caliciviruses. Here, we identified a novel virus phylogenetically related to polymycoviruses, from the phytopathogenic fungus Fusarium oxysporum. The virus, termed Hadaka virus 1 (HadV1), has 11 (+)RNA genomic segments, the largest number in known (+)RNA viruses. Nevertheless, HadV1 lacked a typical structural protein of polymycoviruses and was not pelleted by standard ultracentrifugation, implying an unusual capsidless nature of HadV1. This study reveals a potential novel lifestyle of multisegmented RNA viruses. No potential conflict of interest relevant to this article was reported.

Elsevier Acta Medica Okayama 2666-478X 1 2020 Dicer monitoring in a model filamentous fungus host, Cryphonectria parasitica 100001 EN Annisa Aulia Institute of Plant Science and Resources, Okayama University Midori Tabara Tokyo University of Agriculture and Technology, Department of Applied Biological Sciences Paul Telengech Institute of Plant Science and Resources, Okayama University Toshiyuki Fukuhara Tokyo University of Agriculture and Technology, Department of Applied Biological Sciences Nobuhiro Suzuki Institute of Plant Science and Resources, Okayama University The ascomycete Cryphonectria parasitica has served as a model filamentous fungus for studying virus host interactions because of its susceptibility to diverse viruses, its genetic manipulability and the availability of many biological and molecular tools. Cryphonectria prasitica is known to activate antiviral RNA silencing upon infection by some viruses via transcriptional up-regulation of key RNA silencing genes. Here, utilizing a newly developed GFP-based reporter system to monitor dicer-like 2 (dcl2) transcript levels, we show different levels of antiviral RNA silencing activation by different viruses. Some viruses such as mycoreovirus 1, a suppressor-lacking mutant of Cryphonectria hypovirus 1 (CHV1-Δp69) and Rosellinia necatrix partitivirus 11 (RnPV11) highly induced RNA silencing, while others such as CHV3, Rosellinia necatrix victorivirus 1 and RnPV19 did not. There was considerable variation in dcl2 induction by different members within the family Hypoviridae with positive-sense single-stranded RNA genomes or Partitiviridae with double-stranded RNA genomes. Northern blotting and an in vitro Dicer assay developed recently by us using mycelial homogenates validated the reporter assay results for several representative virus strains. Taken together, this study represents a development in the monitoring of Dicer activity in virus-infected C. parasitica. No potential conflict of interest relevant to this article was reported.

Frontiers Media Acta Medica Okayama 1664-302X 11 2020 Diverse Partitiviruses From the Phytopathogenic Fungus,Rosellinia necatrix 1064 EN Paul Telengech Institute of Plant Science and Resources, Okayama University Sakae Hisano Institute of Plant Science and Resources, Okayama University Cyrus Mugambi Institute of Plant Science and Resources, Okayama University Kiwamu Hyodo Institute of Plant Science and Resources, Okayama University Juan Manuel Arjona-Lopez Institute of Plant Science and Resources, Okayama University Carlos Jose Lopez-Herrera Institute for Sustainable Agriculture,Spanish Research Council Satoko Kanematsu Institute of Fruit Tree Science, National Agriculture and Food Research Organization (NARO) Hideki Kondo Institute of Plant Science and Resources, Okayama University Nobuhiro Suzuki Institute of Plant Science and Resources, Okayama University Partitiviruses (dsRNA viruses, familyPartitiviridae) are ubiquitously detected in plants and fungi. Although previous surveys suggested their omnipresence in the white root rot fungus,Rosellinia necatrix, only a few of them have been molecularly and biologically characterized thus far. We report the characterization of a total of 20 partitiviruses from 16R. necatrixstrains belonging to 15 new species, for which "Rosellinia necatrix partitivirus 11-Rosellinia necatrix partitivirus 25" were proposed, and 5 previously reported species. The newly identified partitiviruses have been taxonomically placed in two genera,Alphapartitivirus, andBetapartitivirus. Some partitiviruses were transfected into reference strains of the natural host,R. necatrix, and an experimental host,Cryphonectria parasitica, using purified virions. A comparative analysis of resultant transfectants revealed interesting differences and similarities between the RNA accumulation and symptom induction patterns ofR. necatrixandC. parasitica. Other interesting findings include the identification of a probable reassortment event and a quintuple partitivirus infection of a single fungal strain. These combined results provide a foundation for further studies aimed at elucidating mechanisms that underly the differences observed. No potential conflict of interest relevant to this article was reported.

Frontiers Media Acta Medica Okayama 1664-302X 11 2020 Virome Analysis of Aphid Populations That Infest the Barley Field: The Discovery of Two Novel Groups of Nege/Kita-Like Viruses and Other Novel RNA Viruses 509 EN Hideki Kondo Institute of Plant Science and Resources (IPSR), Okayama University Miki Fujita Institute of Plant Science and Resources (IPSR), Okayama University Hiroshi Hisano Institute of Plant Science and Resources (IPSR), Okayama University Kiwamu Hyodo Institute of Plant Science and Resources (IPSR), Okayama University Ida Bagus Andika College of Plant Health and Medicine, Qingdao Agricultural University Nobuhiro Suzuki Institute of Plant Science and Resources (IPSR), Okayama University Aphids (order Hemiptera) are important insect pests of crops and are also vectors of many plant viruses. However, little is known about aphid-infecting viruses, particularly their diversity and relationship to plant viruses. To investigate the aphid viromes, we performed deep sequencing analyses of the aphid transcriptomes from infested barley plants in a field in Japan. We discovered virus-like sequences related to nege/kita-, flavi-, tombus-, phenui-, mononega-, narna-, chryso-, partiti-, and luteoviruses. Using RT-PCR and sequence analyses, we determined almost complete sequences of seven nege/kitavirus-like virus genomes; one of which was a variant of the Wuhan house centipede virus (WHCV-1). The other six seem to belong to four novel viruses distantly related to Wuhan insect virus 9 (WhIV-9) or Hubei nege-like virus 4 (HVLV-4). We designated the four viruses as barley aphid RNA virus 1 to 4 (BARV-1 to -4). Moreover, some nege/kitavirus-like sequences were found by searches on the transcriptome shotgun assembly (TSA) libraries of arthropods and plants. Phylogenetic analyses showed that BARV-1 forms a clade with WHCV-1 and HVLV-4, whereas BARV-2 to -4 clustered with WhIV-9 and an aphid virus, Aphis glycines virus 3. Both virus groups (tentatively designated as Centivirus and Aphiglyvirus, respectively), together with arthropod virus-like TSAs, fill the phylogenetic gaps between the negeviruses and kitaviruses lineages. We also characterized the flavi/jingmen-like and tombus-like virus sequences as well as other RNA viruses, including six putative novel viruses, designated as barley aphid RNA viruses 5 to 10. Interestingly, we also discovered that some aphid-associated viruses, including nege/kita-like viruses, were present in different aphid species, raising a speculation that these viruses might be distributed across different aphid species with plants being the reservoirs. This study provides novel information on the diversity and spread of nege/kitavirus-related viruses and other RNA viruses that are associated with aphids. No potential conflict of interest relevant to this article was reported.

Microbiology Society Acta Medica Okayama 0022-1317 100 9 2019 ICTV Virus Taxonomy Profile: Megabirnaviridae 1269 1270 EN Yukiyo Sato Institute of Plant Science and Resources, Okayama University Naoyuki Miyazaki Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance, University of Tsukuba Satoko Kanematsu National Agriculture and Food Research Organization (NARO) Headquarters Jiatao Xie College of Plant Science and Technology, Huazhong Agricultural University Said A. Ghabrial Department of Plant Pathology, University of Kentucky Bradley I. Hillman Department of Plant Biology and Pathology, Rutgers University Nobuhiro Suzuki Institute of Plant Science and Resources (IPSR), Okayama University Megabirnaviridae is a family of non-enveloped spherical viruses with dsRNA genomes of two linear segments, each of 7.2-8.9 kbp, comprising 16.1 kbp in total. The genus Megabirnavirus includes the species Rosellinia necatrix megabirnavirus 1, the exemplar isolate of which infects the white root rot fungus (Rosellinia necatrix) to which it confers hypovirulence. Megabirnaviruses are characterized by their bisegmented genome with large 5'-untranslated regions (1.6 kb) upstream of both 5'-proximal coding strand ORFs, and large protrusions on the particle surface. This is a summary of the ICTV Report on the family Megabirnaviridae, which is available at ictv.global/report/megabirnaviridae. No potential conflict of interest relevant to this article was reported.

Humana Press Acta Medica Okayama 2014 Detection and analysis of non-retroviral RNA virus-like elements in plant, fungal, and insect genomes. 73 88 EN Hideki Kondo Institute of Plant Science and Resources (IPSR), Okayama University Sotaro Chiba Institute of Plant Science and Resources (IPSR)Okayama University Nobuhiro Suzuki Institute of Plant Science and Resources (IPSR), Okayama University Endogenous non-retroviral RNA like sequences (NRVSs) have been discovered in the genome of a wide range of eukaryotes. These are considered as fossil RNA viral elements integrated into host genomes by as-yet-known mechanisms, and in many cases, those fossils are estimated to be millions-of-years-old. It is likely that the number of NRVS records will increase rapidly due to the growing availability of whole-genome sequences for many kinds of eukaryotes. Discovery of the novel NRVSs and understanding of their phylogenetic relationship with modern viral relatives provide important information on deep evolutionary history of RNA virus-host interactions. In this chapter, therefore, the common strategies for the identification and characterization of endogenous NRVSs from plants, insects, and fungi are described. No potential conflict of interest relevant to this article was reported.

Springer Acta Medica Okayama 0304-8608 159 1 2013 Complete genome sequence of Habenaria mosaic virus, a new potyvirus infecting a terrestrial orchid (Habenaria radiata) in Japan 163 166 EN Hideki Kondo Institute of Plant Science and Resources (IPSR), Okayama University Takanori Maeda College of Bioresource SciencesNihon University I Wayan Gara Institute of Plant Science and Resources (IPSR)Okayama University Sotaro Chiba Institute of Plant Science and Resources (IPSR)Okayama University Kazuyuki Maruyama Institute of Plant Science and Resources (IPSR)Okayama University Tetsuo Tamada Institute of Plant Science and Resources (IPSR)Okayama University Nobuhiro Suzuki Institute of Plant Science and Resources (IPSR), Okayama University The complete genomic sequence of Habenaria mosaic virus (HaMV), which infects terrestrial orchids (Habenaria radiata), has been determined. The genome is composed of 9,499 nucleotides excluding the 3'-terminal poly(A) tail, encoding a large polyprotein of 3,054 amino acids with the genomic features typical of a potyvirus. Putative proteolytic cleavage sites were identified by sequence comparison to those of known potyviruses. The HaMV polyprotein showed 58 % amino acid sequence identity to that encoded by the most closely related potyvirus, tobacco vein banding mosaic virus. Phylogenetic analysis of the polyprotein amino acid sequence and its coding sequences confirmed that HaMV formed a cluster with the chilli veinal mottle virus group, most of which infect solanaceous plants. These results suggest that HaMV is a distinct member of the genus Potyvirus. No potential conflict of interest relevant to this article was reported.

Springer Acta Medica Okayama 0304-8608 160 8 2015 Cymbidium chlorotic mosaic virus, a new sobemovirus isolated from a spring orchid (Cymbidium goeringii) in Japan. 2099 104 EN Hideki Kondo Institute of Plant Science and Resources (IPSR), Okayama University Shogo Takemoto Institute of Plant Science and Resources (IPSR)Okayama University Kazuyuki Maruyama Institute of Plant Science and Resources (IPSR)Okayama University Sotaro Chiba Institute of Plant Science and Resources (IPSR)Okayama University Ida Bagus Andika Institute of Plant Science and Resources (IPSR)Okayama University Nobuhiro Suzuki Institute of Plant Science and Resources (IPSR), Okayama University Cymbidium chlorotic mosaic virus (CyCMV), isolated from a spring orchid (Cymbidium goeringii), was characterized molecularly. CyCMV isometric virions comprise a single, positive-strand RNA genome of 4,083 nucleotides and 30-kDa coat protein. The virus genome contains five overlapping open reading frames with a genomic organization similar to that of sobemoviruses. BLAST searches and phylogenetic analysis revealed that CyCMV is most closely related to papaya lethal yellowing virus, a proposed dicot-infecting sobemovirus (58.8 % nucleotide sequence identity), but has a relatively distant relationship to monocot-infecting sobemoviruses, with only modest sequence identities. This suggests that CyCMV is a new monocot-infecting member of the floating genus Sobemovirus. No potential conflict of interest relevant to this article was reported.

Elsevier Science Acta Medica Okayama 01681702 213 2016 Sequence and phylogenetic analyses of novel totivirus-like double-stranded RNAs from field-collected powdery mildew fungi 353 364 EN Hideki Kondo Institute of Plant Science and Resources (IPSR), Okayama University Sakae Hisano Institute of Plant Science and Resources (IPSR), Okayama University Sotaro Chiba Institute of Plant Science and Resources (IPSR), Okayama University Kazuyuki Maruyama Institute of Plant Science and Resources (IPSR), Okayama University Ida Bagus Andika Institute of Plant Science and Resources (IPSR), Okayama University Kazuhiro Toyoda Graduate School of Environmental and Life Science, Okayama University Fumihiro Fujimori Department of Environmental Education, Tokyo Kasei University Nobuhiro Suzuki Institute of Plant Science and Resources (IPSR), Okayama University The identification of mycoviruses contributes greatly to understanding of the diversity and evolutionary aspects of viruses. Powdery mildew fungi are important and widely studied obligate phytopathogenic agents, but there has been no report on mycoviruses infecting these fungi. In this study, we used a deep sequencing approach to analyze the double-stranded RNA (dsRNA) segments isolated from field-collected samples of powdery mildew fungus-infected red clover plants in Japan. Database searches identified the presence of at least ten totivirus (genus Totivirus)-like sequences, termed red clover powdery mildew-associated totiviruses (RPaTVs). The majority of these sequences shared moderate amino acid sequence identity with each other (<44%) and with other known totiviruses (<59%). Nine of these identified sequences (RPaTV1a, 1b and 2-8) resembled the genome of the prototype totivirus, Saccharomyces cerevisiae virus-L-A (ScV-L-A) in that they contained two overlapping open reading frames (ORFs) encoding a putative coat protein (CP) and an RNA dependent RNA polymerase (RdRp), while one sequence (RPaTV9) showed similarity to another totivirus, Ustilago maydis virus H1 (UmV-H1) that encodes a single polyprotein (CP-RdRp fusion). Similar to yeast totiviruses, each ScV-L-A-like RPaTV contains a -1 ribosomal frameshift site downstream of a predicted pseudoknot structure in the overlapping region of these ORFs, suggesting that the RdRp is translated as a CP-RdRp fusion. Moreover, several ScV-L-A-like sequences were also found by searches of the transcriptome shotgun assembly (TSA) libraries from rust fungi, plants and insects. Phylogenetic analyses show that nine ScV-L-A-like RPaTVs along with ScV-L-A-like sequences derived from TSA libraries are clustered with most established members of the genus Totivirus, while one RPaTV forms a new distinct clade with UmV-H1, possibly establishing an additional genus in the family. Taken together, our results indicate the presence of diverse, novel totiviruses in the powdery mildew fungus populations infecting red clover plants in the field. No potential conflict of interest relevant to this article was reported.

Academic Press Acta Medica Okayama 00426822 533 2019 Two novel fungal negative-strand RNA viruses related to mymonaviruses and phenuiviruses in the shiitake mushroom (Lentinula edodes) 125 136 EN Yu-Hsin Lin Institute of Plant Science and Resources (IPSR), Okayama University Miki Fujita Institute of Plant Science and Resources (IPSR), Okayama University Sotaro Chiba Graduate School of Bioagricultural Sciences, Nagoya University Kiwamu Hyodo Institute of Plant Science and Resources (IPSR), Okayama University Ida Bagus Andika Institute of Plant Science and Resources (IPSR), Okayama University Nobuhiro Suzuki Institute of Plant Science and Resources (IPSR), Okayama University Hideki Kondo Institute of Plant Science and Resources (IPSR), Okayama University Abstract There is still limited information on the diversity of (−)ssRNA viruses that infect fungi. Here, we have discovered two novel (−)ssRNA mycoviruses in the shiitake mushroom (Lentinula edodes). The first virus has a monopartite RNA genome and relates to that of mymonaviruses (Mononegavirales), especially to Hubei rhabdo-like virus 4 from arthropods and thus designated as Lentinula edodes negative-strand RNA virus 1. The second virus has a putative bipartite RNA genome and is related to the recently discovered bipartite or tripartite phenui-like viruses (Bunyavirales) associated with plants and ticks, and designated as Lentinula edodes negative-strand RNA virus 2 (LeNSRV2). LeNSRV2 is likely the first segmented (−)ssRNA virus known to infect fungi. Its smaller RNA segment encodes a putative nucleocapsid and a plant MP-like protein using a potential ambisense coding strategy. These findings enhance our understanding of the diversity, evolution and spread of (−)ssRNA viruses in fungi. No potential conflict of interest relevant to this article was reported.

Elsevier Science Acta Medica Okayama 01681702 262 2019 A novel insect-infecting virga/nege-like virus group and its pervasive endogenization into insect genomes 37 47 EN Hideki Kondo Institute of Plant Science and Resources (IPSR), Okayama University Sotaro Chiba Asian Satellite Campuses Institute, Nagoya University Kazuyuki Maruyama Institute of Plant Science and Resources (IPSR), Okayama University Ida Bagus Andika Institute of Plant Science and Resources (IPSR), Okayama University Nobuhiro Suzuki Institute of Plant Science and Resources (IPSR), Okayama University Insects are the host and vector of diverse viruses including those that infect vertebrates, plants, and fungi. Recent wide-scale transcriptomic analyses have uncovered the existence of a number of novel insect viruses belonging to an alphavirus-like superfamily (virgavirus/negevirus-related lineage). In this study, through an in silico search using publicly available insect transcriptomic data, we found numerous virus-like sequences related to insect virga/nege-like viruses. Phylogenetic analysis showed that these novel viruses and related virus-like sequences fill the major phylogenetic gaps between insect and plant virga/negevirus lineages. Interestingly, one of the phylogenetic clades represents a unique insect-infecting virus group. Its members encode putative coat proteins which contained a conserved domain similar to that usually found in the coat protein of plant viruses in the family Virgaviridae. Furthermore, we discovered endogenous viral elements (EVEs) related to virga/nege-like viruses in the insect genomes, which enhances our understanding on their evolution. Database searches using the sequence of one member from this group revealed the presence of EVEs in a wide range of insect species, suggesting that there has been prevalent infection by this virus group since ancient times. Besides, we present detailed EVE integration profiles of this virus group in some species of the Bombus genus of bee families. A large variation in EVE patterns among Bombus species suggested that while some integration events occurred after the species divergence, others occurred before it. Our analyses support the view that insect and plant virga/nege-related viruses might share common virus origin(s). No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 73 4 2019 A Case of Primary Colonic Signet Ring Cell Carcinoma in a Young Man which Preoperatively Mimicked Phlebosclerotic Colitis 361 365 EN Ayako Watanabe Department of Surgery, Japanese Red Cross Kobe Hospital Yoshihiko Kadowaki Department of Surgery, Japanese Red Cross Kobe Hospital Kenji Hattori Department of Surgery, Japanese Red Cross Kobe Hospital Mika Ohmori Department of Radiology, Japanese Red Cross Kobe Hospital Hiroyuki Tsukayama Department of Surgery, Japanese Red Cross Kobe Hospital Nobuhito Kubota Department of Surgery, Japanese Red Cross Kobe Hospital Tatsuo Okumoto Department of Surgery, Japanese Red Cross Kobe Hospital Nobuhiro Ishido Department of Surgery, Japanese Red Cross Kobe Hospital Takeshi Okino Department of Pathology, Japanese Red Cross Kobe Hospital Case Report 10.18926/AMO/56939 A 35-year-old man was referred to our hospital for chronic abdominal pain and diarrhea. Computed tomography showed wall thickening, poor contrast enhancement and calcification of the ascending colon, which were consistent with phlebosclerotic colitis. Malignant character was not detected from a biopsy specimen. Operatively, we observed a scirrhous mass of the ascending colon invading surrounding tissue, which was diagnosed as signet ring cell carcinoma based on analysis of an intraoperative frozen section. Right hemicolectomy with regional lymph node dissection was performed. This case was extremely similar to phlebosclerotic colitis in clinical findings; surgical resection was required for correct diagnosis. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 67 6 2013 A New Navigation System for Minimally Invasive Total Knee Arthroplasty 351 358 EN Yusuke Yokoyama Nobuhiro Abe Kazuo Fujiwara Masahiko Suzuki Yoshikazu Nakajima Naohiko Sugita Mamoru Mitsuishi Yoshio Nakashima Toshifumi Ozaki Original Article 10.18926/AMO/52008 A computer-assisted navigation system to be used for total knee arthroplasties (TKAs) was reported to improve the accuracy of bone resection and result in precise implant placement, but the concomitant surgical invasion and time consumption are clinical problems. We developed a computed tomography (CT)-based navigation system (NNS) to be used for minimally invasive TKA. It requires only the reference points from a small limited area of the medial femoral condyle and proximal tibia through a skin incision to obtain optical images. Here we evaluated the usefulness and accuracy of the NNS in comparison with the commercially available BrainLAB image-free navigation system (BLS). In a clinical experiment, the registration times obtained with the NNS tended to be shorter than those obtained with the BLS, but not significantly so. The NNS group tended to be in the extended position in the sagittal plane of the distal femur within 3 degrees, and the BLS group showed rather flexed deviation in the sagittal plane of the anterior femur. No potential conflict of interest relevant to this article was reported.

Okayama University Medical School Acta Medica Okayama 0386-300X 50 6 1996 Increased endothelial and epidermal thrombomodulin expression and plasma thrombomodulin level in progressive systemic sclerosis. 293 297 EN Hitoshi Mizutani Tatsuya Hayashi Nobuhiro Nouchi Shin Inachi Koji Suzuki Masayuki Shimizu Article 10.18926/AMO/30479 <p>To clarify the relation between systemic and cutaneous vascular endothelial injury in progressive systemic sclerosis (PSS), we examined thrombomodulin (TM) expression in PSS skin lesions immuno-histopathologically and compared it with plasma soluble TM levels measured by specific enzyme-linked immunosorbent assay. The plasma soluble TM level in PSS patients was significantly higher than that of normal controls and was as high as the levels of SLE patients. In relation to disease activities, the plasma TM levels of sclerotic phase PSS patients were significantly higher than that of atrophic phase PSS patients. The plasma samples with anti-Scl-70 antibody showed a high TM level than samples with anti-centromere antibody or anti-RNP antibody. Barnett's types or systemic corticosteroid treatment did not affect the TM level. Histopathologically, the dermal endothelial TM expression significantly increased in the sclerotic skin and moderately increased in the non-sclerotic skin of PSS compared with that of normal control skin. In addition, immunoreactive TM expression in the epidermis also increased in PSS. Disease activity-dependent elevation of plasma TM levels and immuno-histopathological expression of TM suggested generalized endothelial and epidermal cell involvement in PSS, and compensation in part by overproduction of TM by endothelial cells.</p> No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 0030-1558 116 1 2004 心不全における酸化ストレスの関与：基礎的ならびに臨床的検討 ―岡山大学医学賞（結城賞）を受賞して― 9 16 EN 心不全患者において血中の過酸化脂質の上昇などが報告され，活性酸素による酸化ストレスの関与が示唆されている．そこで，心筋が実際に活性酸素を発生するかどうかを，活性酸素を検出する蛍光プローブを用いてラットの培養心筋細胞において検討した．心不全増悪因子であるアンジオテンシンIIおよびtumor necrosis factor(TNF)-alphaを加えると心筋細胞で濃度依存性に活性酸素が発生した．さらにヒトの不全心筋においても実際に酸化ストレスの発生が増強しているかを検討した．過酸化脂質の代謝産物で，有害なアルデヒドである4-Hydroxy-2-nonenal(HNE)によって修飾された蛋白質を免疫染色にて調べたところ，拡張型心筋症患者の心筋において正常心機能者に比べ5倍以上増加していた．さらにβ遮断薬(Carvedilol)により治療を行ったところ心機能の改善とともに，HNE修飾蛋白質が40%低下した．以上の一連の研究により， 活性酸素による酸化ストレスの発生が不全心筋において増強しており，その抑制が心不全治療のターゲットの一つになりうることを明らかにした． No potential conflict of interest relevant to this article was reported.

岡山医学会 Acta Medica Okayama 00301558 120 1 2008 頻回な心室性不整脈を呈した Brugada 症候群に対する低用量 Isoproterenol の治療効果の検討 35 41 EN Atsuyuki Watanabe Kengo Kusano Fukushima Hiroshi Morita Daiji Miura Wakako Sumida Shigeki Hiramatsu Kimikazu Banba Nobuhiro Nishii Satoshi Nagase Kazufumi Nakamura Satoru Sakuragi Tohru Ohe No potential conflict of interest relevant to this article was reported.