Chen, F., M.T. Cottrell and C.A. Suttle. 1995. Phylogeny of large double-stranded DNA viruses which infect microalgae, as inferred from DNA polymerase gene sequences. Abstracts American Society Virology, Austin, TX, July 1995.
Phylogenetic relationships among algal viruses and other large dsDNA viruses was inferred from virus-encoded DNA polymerase gene sequences, which were amplified from viruses which infect several genera of distantly related microalgae (Chlorella spp., Micromonas pusilla and Chrysochromulina spp.). Based on nucleotide and inferred amino acid sequences, different virus isolates infecting the same host formed a closely related group relative to other algal viruses, and algal viruses were more closely related to each other than to viruses which infect other eukaryotes. This suggests that these viruses belong within the recently described family, Phycodnaviridae. Similar phylogenies were inferred by distance and parsimony methods, and showed that herpes viruses are most closely related to the algal viruses. As well, the vaccinia virus shares relatively high similarities to the algal virus group. These findings are consistent with the DNA polymerase genes of algal viruses having evolved from a common ancestral gene, as has been suggested for other RNA-primed B-family DNA polymerase genes.