Nucleotide sequences of goose circovirus isolated in Taiwan

Abstract

We report the complete nucleotide (nt) sequences of eleven goose circovirus (GoCV) isolated in Taiwan. Nine out of the eleven isolates had a genome size of 1821 nt, whereas the remaining two isolates have a size of 1820 nt. Sequence comparisons of the eleven Taiwanese GoCV isolates and a German isolate revealed that these viruses could be divided into three distinct genetic groups. Group I contains the German isolate, group II contains three Taiwanese isolates, and group III contains eight Taiwanese isolates. Nucleotide differences between viruses of different genetic groups ranged from 7.0-7.7%, whereas the differences within the same group were only 0.2-1.0%. The most diversified sequences were found at a region between nt 27-72 of the viral genome, which corresponded to the right one-third of the 5' intergenic region. Open reading frame analysis shows that the genome of all Taiwanese GoCV isolates could encode four proteins: V1 (Rep, 293 amino acids), V2 (37 amino acids), C1 (capsid, 250 amino acids), and C2 (99 amino acids). The sizes of V1, C1 and C2 proteins of all Taiwanese isolates and the German GoCV isolates were identical. However, the size of V2 protein (37 amino acids), although identical in all Taiwanese isolates, was much smaller than that of the German isolate (120 amino acids). Moreover, the initiation codon of the V2 ORF of three Taiwanese isolates was ATA rather than ATG. Our result indicates that GoCV of multiple genetic groups might have been circulating in Europe and Asia, and these viruses differ in their nucleotide sequences, sizes of the genome, and sizes of the V2 ORFs.