Full-length genome characterization of a new fusagravirus hosted by the spring orange peel fungus Caloscypha fulgens


ACTA VIROLOGICA, vol.65, no.3, pp.313-319, 2021 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 65 Issue: 3
  • Publication Date: 2021
  • Doi Number: 10.4149/av_2021_309
  • Journal Name: ACTA VIROLOGICA
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Aquatic Science & Fisheries Abstracts (ASFA), BIOSIS, CAB Abstracts, EMBASE, MEDLINE, Veterinary Science Database
  • Page Numbers: pp.313-319
  • Keywords: mycovirus, dsRNA, proposed Fusagraviridae, uncultivated fungi, Caloscypha fulgens, STRANDED RNA VIRUS, MYCOVIRUS
  • Dokuz Eylül University Affiliated: Yes


Mycoviruses widely exist in diverse lineages of fungi, yet there are only a few studies on mycovirus infection in uncultivated fungi. We here report the presence of a dsRNA mycovirus in saprotrophic spring orange peel fungus Caloscypha fulgens. A novel dsRNA virus, named "Caloscypha fulgens fusagravirus 1" (CfFV1), was isolated from a single ascocarp of C. fulgens, and its molecular features were revealed. The full-length cDNA of CfFV1 comprises 9,548 nucleotides with a calculated GC content of 47.9% and two discontinuous open reading frames (ORF 1 and 2). A-1 ribosomal frameshift region with two distinctive elements, including a canonical slippery heptanucleotide (AAAAAAC) and a pseudoknot structure, predicted as a Recoding Stimulatory Element, was detected in the junction region of ORF1 and ORF2. The deduced amino acid sequence of ORF1 and ORF2 showed the highest similarity to the putative structural protein and RNA-dependent RNA polymerase (RdRp) of Rosellinia necatrix fusagravirus 4 (RnFGV4). Genome organization, sequence similarity, and phylogenetic analysis indicate that this virus belongs to a new member of the proposed family Fusagraviridae. This is the first report of the presence of a mycovirus in the spring orange peel fungus C. fulgens.