Genetic characterization of Aleutian mink disease viruses isolated in China

Aleutian mink disease virus (AMDV) is a parvovirus that causes an immune complex mediated disease in minks. To understand the genetic characterization of AMDV in China, the genomic sequences of three isolates, ADV-LN1, ADV-LN2, and ADV-LN3, from different farms in the Northern China were analyzed. The results showed that the lengths of genomic sequences of three isolates were 4,543, 4,566, and 4,566 bp, respectively. They shared only 95.5-96.3 % nucleotide identity with each other. The nucleotide and amino acid homology of genome sequence between the Chinese isolates and European or American strains (ADV-G, ADV-Utah1, and ADV-SL3) were 92.4-95.0 % and 92.1-93.8 %, respectively. The amino acid substitutions randomly distributed in the genome, especially NS gene. ADV-LN1 strain had a 9-amino-acid deletion at amino acid positions 70 and 72-79 in the VP1 gene, comparing with ADV-G strain; ADV-LN2 and ADV-LN3 strains had 1-amino-acid deletion at amino acid positions 70 in the VP1. Some potential glycosylation site mutations in VP and NS genes were also observed. Phylogenetic analysis results showed that the three strains belonged to two different branches based on the complete coding sequence of VP2 gene. However, they all were in the same group together with the strains from United States based on the NS1 sequence. It indicated that Chinese AMDV isolates had genetic diversity. The origin of the ancestors of the Chinese AMDV strains might be associated with the American strains.