Phylogenetic analysis
To investigate the evolutionary relationship of DAstV -SDZZ with other
astroviruses for which corresponding sequences were available,
phylogenetic trees were constructed based on nucleotide sequences of the
ORF 1a, ORF 1b and ORF 2 homologous genome (Figure 2). All the three
trees demonstrated that the DAstV -SDZZ isolate located on the identical
branch as the other DAstV-1. The DAstV-1 strain was closely related to
some turkey astroviruses in ORF 1a and ORF 2 genes, whereas DAstV-1
formed another clade with CAstV and DAstV CPH in the ORF2 region.
Comparison of the other DAstV-1 strain with the deduced amino acid
sequences of DAstV-SDZZ isolate were performed. As shown in Table 1, the
deduced amino acid sequences of the DAstV-SDZZ with other DAstV-1 strain
shared identities of 94.4% to 99% in ORF1a, 96.9% to 98.4% in ORF1b,
and 95.5% to 99.9% in ORF2. The amino acid of capsid protein of the
DAstV-SDZZ shared identities of 40.5% and 56–56.1% with TAstV-1 and
GoAstV strains, respectively. These observations suggest that DAstV-SDZZ
is an isolate of DAstV-1.