The housefly virus contains double-stranded RNA

The housefly virus (HFV) was shown to contain double-stranded RNA (dsRNA) when examined by fluorescent staining with acridine orange (AO). The pale green color observed was not affected by digestion with single-stranded specific nuclease. In contrast, denatured wet, but not dried virus samples fluoresced red. Viral RNA, extracted and analyzed by polyacrylamide gel electrophoresis, was resolved into 10 segments, which were not affected by predigestion with RNase, confirming the ds nature of the genome. The HFV thus belongs to the family Reoviridae. By comparison with dsRNA segments from reovirus type 3, Dearing strain, the housefly virus genome is estimated to have a molecular weight of 17 to 18 x 10(6) daltons.