The complete RNA genome of Avian Nephritis virus (ANV) associated with acute nephritis in chickens has been molecularly cloned and sequenced. Excluding the poly(A) tail, the genome comprises 6,927 nucleotides, and contains three sequential open reading frames (ORFs). The first ORF (ORF 1a) contained a serine protease motif, and the second ORF (ORF 1b) had a RNA-dependent RNA polymerase. The ORF 1a may be linked to the second ORF by a ribosomal frameshifting mechanism. The third ORF (ORF 2) may encode the virion structural proteins as a polyprotein precursor. The amino acid homology of ORF 1a, 1b, and 2 were 20.3%, 41.9% and 25.8% with those of human astrovirus serotype 1 (A/88 Newcastle strain), respectively. These observations suggested that the ANV (G-4260 strain) is a new genus of the family Astroviridae. (Lab. of Viral Pathogenesis, Department of Virology TEL +81-298-38-7760)
