Project description:The phylogeny of reptilian herpesviruses (HVs) relative to mammalian and avian HVs was investigated by using available gene sequences and by alignment of encoded amino acid sequences and derivation of trees by maximum-likelihood and Bayesian methods. Phylogenetic loci were obtained for green turtle HV (GTHV) primarily on the basis of DNA polymerase (POL) and DNA binding protein sequences, and for lung-eye-trachea disease-associated HV (LETV) primarily from its glycoprotein B sequence; both have nodes on the branch leading to recognized species in the Alphaherpesvirinae subfamily and should be regarded as new members of that subfamily. A similar but less well defined locus was obtained for an iguanid HV based on a partial POL sequence. On the basis of short POL sequences (around 60 amino acid residues), it appeared likely that GTHV and LETV belong to a private clade and that three HVs of gerrhosaurs (plated lizards) are associated with the iguanid HV. Based on phylogenetic branching patterns for mammalian HV lineages that mirror those of host lineages, we estimated a date for the HV tree's root of around 400 million years ago. Estimated dates for branching events in the development of reptilian, avian, and mammalian Alphaherpesvirinae lineages could plausibly be accounted for in part but not completely by ancient coevolution of these virus lines with reptilian lineages and with the development of birds and mammals from reptilian progenitors.
Project description:The Herpesviridae are a large group of well-characterized double-stranded DNA viruses for which many complete genome sequences have been determined. We have extracted protein sequences from all predicted open reading frames of 19 herpesvirus genomes. Sequence comparison and protein sequence clustering methods have been used to construct herpesvirus protein homologous families. This resulted in 1692 proteins being clustered into 243 multiprotein families and 196 singleton proteins. Predicted functions were assigned to each homologous family based on genome annotation and published data and each family classified into seven broad functional groups. Phylogenetic profiles were constructed for each herpesvirus from the homologous protein families and used to determine conserved functions and genomewide phylogenetic trees. These trees agreed with molecular-sequence-derived trees and allowed greater insight into the phylogeny of ungulate and murine gammaherpesviruses.