Abstract
Herpesviral viral lesions have been previously described1, but have not been cultured or characterized molecularly in beluga whales. There have been molecular characterizations of herpesviruses in a variety of other cetaceans and some have been associated with a variety of pathology including encephalitis,2 systemic necrotizing lesions,3 genital and skin lesions4. As part of a live-capture study of beluga whales in Bristol Bay, Alaska, herpesviruses were isolated from blowhole swabs from 4 animals and one was also isolated from a beluga from the Cook Inlet stock. The Bristol Bay beluga stock are the closest genetically, ecologically and geographically to the Cook Inlet beluga stock,5 which was listed as endangered in 20086. Thus the Bristol Bay belugas are a useful comparison or control population for Cook Inlet belugas. Isolates obtained from blowhole swabs were cultured in beluga whale kidney (BWK) cell lines. DNA extracted from infected tissue culture fluids was amplified by PCR targeting the DNA polymerase and the thymidine kinase (TK) genes of cetacean alpha-herpesviruses. For the DNA polymerase gene, all nucleotide sequences obtained were virtually identical (99.9–100%) and translated into a protein of 223 amino acids that shared identity with the DNA polymerase of alpha-herpesviruses from Mesoplodon densirostris (78%),4 Lagenorhynchus obliquidens (75%),7 Tursiops aduncus (74%), and Tursiops truncatus (71%)4,8. Sequencing of the TK gene fragment of one of the isolates revealed a sequence of 718 nucleotides with the closest identity (44%) to the TK gene of bovine herpesvirus 1, an alpha-herpesvirus. Several Bristol Bay animals had ulcerative skin lesions; however no isolates were obtained from the lesions although inclusion bodies were seen on histopathology. Isolation of herpesvirus from the blowhole did not correlate with clinical disease, suggesting this unique herpesvirus is most likely well adapted and beluga specific.
Acknowledgements
The authors would like to acknowledge and thank the members of the research and capture crews which includes the hunters of Dillingham, the Bristol Bay Native Association, Lori Quakenbush with the Alaska Department of Fish and Game, Tim Binder, Eric Gaglione, Alistair Dove, Mandy Keogh, Tracey Romano, S. Norman, Leslie Cornick, Amanda Moors, Teri Rowles, Russ Andrews, Brett Long Manuel Castellote. This work was supported by funding through NMML, Georgia, Shedd, and Mystic Aquariums and the Marine Mammal Health and Stranding Network under ADF&G and NOAA Permits 782-1719-06,07 and 932-1489-10 and MMHSRP 932-1905-00/MA-009526.ADF&G Animal Care and Use Committee (#06-16).
* Presenting author
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