Genomic characteristics of a novel non-segmented double-stranded RNA mycovirus from the fungus Nigrospora oryzae

Arch Virol. 2024 Nov 19;169(12):249. doi: 10.1007/s00705-024-06178-1.

Abstract

In this study, a novel virus isolated from Nigrospora oryzae, tentatively named "Nigrospora oryzae mycovirus 1" (NoMyV1), was identified. NoMyV1 has a non-segmented dsRNA genome that is 2891 bp in length and contains two non-overlapping open reading frames (ORF1 and 2). ORF1 encodes a protein with sequence similarity to the putative capsid proteins or hypothetical proteins of other unclassified viruses, while ORF2 encodes an RNA-dependent RNA polymerase (RdRp). Sequence comparisons showed that NoMyV1 was most similar to Penicillium janczewskii Beauveria bassiana-like virus 1 (PjBblV1), with 76.12% amino acid sequence identity in the RdRp. In a phylogenetic analysis based on RdRp sequences, NoMyV1 was found to cluster with several other unclassified viruses for which a new genus, "Unirnavirus", which is distinct from the family Partitiviridae, has been proposed. Thus, we conclude that NoMyV1 is a novel member of the proposed genus "Unirnavirus".

MeSH terms

  • Ascomycota / genetics
  • Ascomycota / virology
  • Double Stranded RNA Viruses* / classification
  • Double Stranded RNA Viruses* / genetics
  • Double Stranded RNA Viruses* / isolation & purification
  • Fungal Viruses* / classification
  • Fungal Viruses* / genetics
  • Fungal Viruses* / isolation & purification
  • Genome, Viral*
  • Genomics
  • Open Reading Frames*
  • Phylogeny*
  • RNA Viruses / classification
  • RNA Viruses / genetics
  • RNA Viruses / isolation & purification
  • RNA, Double-Stranded* / genetics
  • RNA, Viral* / genetics
  • RNA-Dependent RNA Polymerase* / genetics
  • Viral Proteins / genetics

Substances

  • RNA, Double-Stranded
  • RNA, Viral
  • RNA-Dependent RNA Polymerase
  • Viral Proteins