Phylogenetic analysis of novel astroviruses. A) Phylogenetic tree of the ORF1b amplicon generated by the consensus astrovirus primers. Multiple sequence alignments were then generated with these sequences and the corresponding regions of known astroviruses using ClustalX. PAUP was used to generate phylogenetic trees and bootstrap values (>700) from 1,000 replicates are shown. B) Phylogenetic analysis of the complete predicted ORF1b.