National Association of Animal Breeders Technical Conference Student Poster session: Middleton, Wisconsin
Genetic analysis of bovine papillomas
Thomas A. Christensen II Rachel Palinski Bob Gentry
September 19, 2024
Bovine papillomavirus (BPV) is a major cause of reproductive failure in cattle. In bulls, penile papillomas caused by BPV may cause reluctance to breed, and is always a cause to fail an animal on a breeding soundness exam. Historically, it has been thought that BPV was transmitted via direct contact and could be controlled by managing clinically presenting animals in the herd, but more recent evidence suggests alternative modes of transmission. BPV has been found repeatably in clinically healthy animals, and in non-cutaneous secretions including milk, blood, urine and semen. Currently, no commercially available BPV vaccine uses isolated viral particles and naturally occurring virus does not produce cross-protective immunity. In order to develop a proper vaccine for penile papillomas further studies are required to understand the epidemiology of BPV in herds. While vulvar, cutaneous, and mammary papillomas have been genotyped in recent years, this information is not available for penile papillomas. In this study there were 31 submissions, collected from 7 states, NE, KS, NY, TX, AL, MO and SD (14 different cattle operations) Samples were collected between August of 2022 and April 2024. Twenty-two submissions were penile papillomas and with pooling of samples represented over 50 penile papillomas. Samples were metagenomically sequenced at the Kansas State Veterinary Diagnostic Lab, and the genotype of each sample was determined using the phylogenetic analysis. The clade of each sample was determined by aligning consensus sequences of the L1 gene (used for both for phylogeny and as a vaccine target) using MAFFT and a maximum-likelihood phylogeny generated in Mega X. Analysis found that all penile papilloma submissions were composed of BPV type 2, with one sample showing co-infection with BPV type 1. Conversely, cutaneous and teat papillomas had BPV genotypes that were more variable with genotypes of 1,2,7,12,14,29 and 40. These results indicate that BPV type 2 and type 1 provide a unified target for bovine penile papilloma vaccine development.