Abstract
Swabs and a biopsy were collected from two California sea lions (Zalophus californianus) with proliferative lesions on the axillae and prepuce. Degenerate primers were used to amplify partial papillomaviral E1 gene for sequencing.2,3 TBLASTX analysis identified each sequence as papillomaviral. To obtain additional sequence, rolling circle amplification was performed. Specific primers were then designed to close the remaining gaps. No herpesviruses were detected in any samples.4
Analysis of the California sea lion papillomavirus type 1 (ZcPV1) genome revealed seven open reading frames encoding five early (E) proteins (E6, E7, E1, E2 and E4) and two late (L) proteins (L1 and L2), organized in this order. Like all papillomaviruses characterized to date, these proteins are encoded in the same orientation. A non-coding region (NCR) of 704 bp was found after L1 and before the E6 gene.
The L1 gene is routinely used to classify novel papillomaviruses.1 To evaluate the evolutionary relationships of ZcPV1 with other papillomaviruses, sixty-six L1 gene sequences from representatives of all known papillomavirus genera were obtained from GenBank. Phylogenetic analysis of this data set showed that ZcPV1 forms a highly supported monophyletic clade with canine papillomavirus 3 (CPV3), canine papillomavirus 4 (CPV4) and equine papillomavirus 1 (EcPV1). The closest evolutionary relationship of ZcPV1 is with its sister taxa EcPV1, supported with a Bayesian posterior probability of 100%. Based on the levels of nucleotide identity, ZcPV1 would be classified in the same genus as CPV3, CP4 and EcPV1.
Acknowledgements
This work was funded by research grant N° N00014-06-1-0250 from the Office of Naval Research to H.N. and research contract N° N66001-08-D-0070 from the Department of Defense to Dr. Pamela Yochem (Hubbs-SeaWorld Research Institute). All sample collection protocols were approved by the University of Florida Institutional Animal Care and Use Committee (IACUC# C233). We would like to thank Dr. P. Yochem, Dr. Judy St. Leger (SeaWorld San Diego) and Dr. Stephanie Venn-Watson (U.S. Navy Marine Mammal Program Foundation) for their support on this project, including comments on the abstract and presentation. We would also like to thank the staff of the U.S. Navy Marine Mammal Program and for their help with sample collection and Jennifer Burchell and Celeste Benham for their assistance in the laboratory.
References
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