Genomic complexities of murine leukemia and sarcoma, reticuloendotheliosis, and visna viruses

The genetic complexities of several ribodeoxyviruses were measured by quantitative analysis of unique RNase T₁ resistant oligonucleotides from 60-70S viral RNAs. Moloney murine leukemia virus was found to have an RNA complexity of 3.5x10⁶ daltons, whereas Moloney murine sarcoma virus had a significantly smaller genome size of 2.3x10⁶. Reticuloendotheliosis and visna virus RNAs had complexities of 3.9x10⁶ and 3.5x10⁶, respectively. Analysis of RNase A resistant oligonucleotides of Rous sarcoma virus RNA gave a complexity of 3.6x10⁶, similar to that previously obtained with RNase T₁ resistant oligonucleotides. Since each of these viruses was found to have a unique sequence genomic complexity near the molecular weight of a single 30-40S viral RNA sub unit, it was concluded that ribodeoxyvirus genomes are at least largely polypoid.