Avian nephritis virus is the causative agent of baby chick nephropathy. It is also causes entritis growth retardation in broiler chickens. In this investigation a fragmen of ORF1a of a first Iranian isolate of ANV1 was amplified by RT_PCR assay and sequence by cycle sequencing. The amplicon had 87.5% identity in nucleotide level and 96.1% identity and 96.3% similarity rate at amino acid level with the reference sequence of ANV1 originaly isolated in Japan. The phylogenetic tree of amino acid sequence was constructed based on compatible sequence of all ANV1 isolates and other animal astroviruses, which their sequence were available in genetic databases. According to the level of divergence and phylogenetic analysis, the Iranian isolate had close relationship withANV1 reference strain, Although the level of divergence with other reported ANV1 isolated was not so high. It is the first report of presence and partial genetic characterization of ANV1 in Iran.

Keywords