Abstract
Five novel DNA-dependent DNA polymerase (Dpol) herpesviral sequences were generated using nested consensus polymerase chain reaction (PCR) in clinical samples from a harbor seal (Phoca vitulina), bottlenose dolphin (Tursiops truncatus), orca (Orcinus orca), California sea lion (Zalophus californianus), and a phocid herpesvirus 2 (PhHV-2) isolate (used as positive control). As expected for viral polymerase genes, the Dpol region is highly conserved which makes it the gene of choice for exploring the phylogenetic relationships of distantly related organisms.3 These novel sequences and a diverse array of other herpesvirus sequences were included in Bayesian and Maximum Likelihood analyses to illustrate the evolution of herpesviruses amongst the marine mammal host species and in comparison to those of other animals.
All nineteen novel and known marine mammal herpesviruses included in the analyses aligned within the alpha or gamma subfamily of Herpesviridae. The novel harbor seal herpesvirus clustered with Macavirus, a gammaherpesviral genus. The novel bottlenose dolphin herpesvirus clustered together in a monophyletic group with another delphinid alphaherpesvirus but could not be associated with an established genus. The orca herpesvirus also clustered with a delphinid alphaherpesvirus and formed a separate clade. The sea lion herpesvirus clustered with PhHV-2. PhHV-1 clustered with varicelloviruses as previously reported1,2 and PhHV-2 clustered strongly in the Gammaherpesvirinae genus Percavirus. Lastly, all cetacean gammaherpesviruses formed a monotypic clade and could not be associated with an established gammaherpesviral genus.
Acknowledgements
This work was funded by Office of Naval Research grants N°. N00014-06-1-0250 and N°. N00014-09-1-0252 to H.N. We would like to thank the Aquatic Animal Health program at the University of Florida College of Veterinary Medicine for their support.
References
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