Intergeneric Occurrence of Related Fungal Viruses: the Aspergillus ochraceous Virus Complex and Its Relationship to the Penicillium stoloniferum Virus S

Summary Mycoviruses from Aspergillus ochraceous (ATCC 28706) (AoV) and Penicillium stoloniferum (ATCC 14586) (PsV) were isometric, had diameters of 30 to 32 nm and 32 to 34 nm respectively, and resolved into six bands in CsCl at buoyant densities of 1.275 to 1.357 and 1.285 to 1.390 g/cm3, respectively. All properties of PsV were the same as previous reports except an additional RNA segment with a mol. wt. of 0.51 × 106 and a reverse in the ratio of the major and minor capsid polypeptides. The AoV complex contained nine segments of dsRNA with mol. wt. ranging from 1.12 × 106 to 0.38 × 106, and five thermomelting transition points between 76 and 88°C. It contained capsid polypeptides with mol. wt. of 60000, 51000 and 41000. One dsRNA segment (mol. wt. 1.10 × 106) and one capsid polypeptide (mol. wt. 51000) were common to AoV and PsV-S. Serological tests and virus electrophoresis indicated that at least two serologically distinct viruses were present in A. ochraceous. In double-diffusion serological tests one serological component of AoV and PsV reacted with antiserum of the other virus complex, indicating a serological relationship. A 32P-5′-end-labelled probe of AoV RNA hybridized with PsV RNA and a labelled PsV probe hybridized with AoV RNA. It was concluded that one viral component of the AoV complex is related to the PsV-S component of the PsV complex.