California Sea Lion Polyomavirus in Wild Populations: Expansion of the Known Host Range of the Polyomaviridae to Carnivora
Abstract
A novel polyomavirus was first identified in a proliferative polypoid mass with vascular endothelial intranuclear inclusions from the tongue of a stranded California sea lion (Zalophus californianus). The genome was sequenced, and characteristic proteins of polyomaviruses were identified.
Placental mammals are divided into four main superorders: two less speciose clades, Afrotheria (including elephants, manatees, aardvarks, and others) and Xenarthra (armadillos/sloths/anteaters), and two larger clades containing most mammal species, Laurasiatheria (Carnivora / Cetartiodactyla / Perissodactyla / insectivores/bats) and Euarchontoglires (rabbits / rodents / primates).1 This is only the third described polyomavirus of laurasiatherian mammals, is the first of the three associated with a lesion, and is the first known polyomavirus of a host in the order Carnivora. Phylogenetic analysis of the predicted late region proteins found that the laurasiatherian polyomaviruses, together with Squirrel monkey polyomavirus, form a monophyletic clade.
A quantitative PCR was developed and utilized on various samples from 79 additional animals from either managed (n=26) or wild stranded (n=53) California sea lion populations. California sea lion polyomavirus infection was found in 24% of stranded animals. The organs with the highest virus loads were tongue, liver and kidneys. Buffy coats and urine did not appear to be sensitive diagnostic samples. The clinical significance of this virus remains unclear.
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., and Department of Defense Contract N° N66001-08-D-0070 to Dr. Pamela Yochem (Hubbs-SeaWorld Research Institute). The authors would like to thank Liz Wheeler (The Marine Mammal Center), Erika Nilson (SeaWorld San Diego), and Kevin Carlin (National Marine Mammal Foundation) for assistance with sample collection and Dr. Refugio Robles, Dr. P. Yochem, and Jennifer Burchell from the San Diego Hubbs-SeaWorld Research Institute for laboratory assistance and coordination, and comments on the abstract.
References
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