Identification and characterization of the virus causing Rabbit Hemorrhagic disease

Liver tissue from animals that died of rabbit hemorrhagic disease (RHD) was to identify the causative agent. After extraction of liver homogenates and sucrose density gradient ultracentrifugation, distinct bands obtained. The respective gradient fractions reacted positively in an enzyme-linked immunosorbent assay as well as in hemagglutination assays and were infective for rabbits. These fractions contained virions which had a diameter of 40 nm and resembled morphologically those of the family Caliciviridae. By immunoblotting, a major structural protein with a molecular weight of 60,000 was identified. Highly pure RNA of about 8 kilobases was isolated from virions. Labeled cDNA synthesized from virion RNA detected two RNAs of 8 and 2 kilobases in Northern (RNA) blots of liver ENA from infected with RHD virus. Finally, Isolated virion RNA injected into the liver of rabits produced a disease with clinical symptoms and pathological findings typical of RHD. We conclude that a calicivirus represents the causative of RHD.