We previously screened the total nucleic acid extracts of 123 Mucor strains for the
presence of dsRNA molecules without further molecular analyses. Here, we characterized
five novel dsRNA genomes isolated from four different Mucor hiemalis 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 UAAUG pentanucleotide motif points to the fact for coupled
translation termination and reinitialization. MhV1a, MhV2, and MhV3 are part of the
clade representing the genus Victorivirus, while MhV4 is seated in Totivirus genus
clade. The detected VLPs in Mucor strains were from 33 to 36 nm in diameter. Hybridization
analysis revealed that the dsRNA molecules of MhV1a-MhV4 hybridized to the corresponding
molecules.
