Channel catfish virus: use of nucleic acids in studying viral relationships

Restriction digestion patterns were used to determine differences in the DNA of various isolates of channel catfish virus (CCV). All viruses were different from each other and from the type strain of CCV. The differences in the digestion patterns were used to relate the viruses quantitatively as to sequence divergence between all pairs of viruses. A range of values from 104 nucleotide changes to 1,690 nucleotide changes/total DNA of CCV was found for the various pairs. A cladistic analysis produced a phylogenetic network relating the viruses by possible ancestory. This network indicated that some viruses were relatively more separated from other viruses that were clustered in the network. A phenetic analysis indicated that the viruses that were clustered in the network were also reasonably similar to one another.