Project description:We previously screened the total nucleic acid extracts of 123 <i>Mucor</i> strains for the presence of dsRNA molecules without further molecular analyses. Here, we characterized five novel dsRNA genomes isolated from four different <i>Mucor</i> <i>hiemalis</i> strains with next-generation sequencing (NGS), namely Mucor hiemalis virus 1a (MhV1a) from WRL CN(M) 122; Mucor hiemalis virus 1b (MhV1b) from NRRL 3624; Mucor hiemalis virus 2 (MhV2) from NRRL 3616; and Mucor hiemalis virus 3 (MhV3) and Mucor hiemalis virus (MhV4) from NRRL 3617 strains. Genomes contain two open reading frames (ORF), which encode the coat protein (CP) and the RNA dependent RNA polymerase (RdRp), respectively. In MhV1a and MhV1b, it is predicted to be translated as a fusion protein via -1 ribosomal frameshift, while in MhV4 via a rare +1 (or-2) ribosomal frameshift. In MhV2 and MhV3, the presence of specific UA<b>A</b><b>UG</b> pentanucleotide motif points to the fact for coupled translation termination and reinitialization. MhV1a, MhV2, and MhV3 are part of the clade representing the genus <i>Victorivirus</i>, while MhV4 is seated in <i>Totivirus</i> genus clade. The detected VLPs in <i>Mucor</i> strains were from 33 to 36 nm in diameter. Hybridization analysis revealed that the dsRNA molecules of MhV1a-MhV4 hybridized to the corresponding molecules.