Genomic sequences of bovine papillomaviruses in formalin-fixed sarcoids from Australian horses revealed by polymerase chain reaction.

This research paper focused on detecting the presence of bovine papillomavirus in the tissue of sarcoids from Australian horses using a technique called polymerase chain reaction. Of the 76 horse sarcoids tested over a period of ten years, 73% were found to contain this virus.

Introduction and Context

• In this research, the authors primarily aimed to investigate the presence of genomic sequences from bovine papillomavirus 1 and 2 (BPV1, BPV2) in formalin-fixed sarcoids from Australian horses. Sarcoids are common skin tumors in horses which often are assumed to be associated with certain types of viruses.
• A technique known as the polymerase chain reaction (PCR) was used to uncover these sequences. PCR is a widely used method in molecular biology to make many copies of a specific DNA segment, enabling scientists to amplify, or make enough of the target DNA necessary for analysis and study.

Materials and Methods

• A total of 76 formalin-fixed paraffin-embedded (a method of sample preservation) sarcoids from 62 Australian horses, collected over a ten year period, were used in this research.

Results and Analysis

• From the total 76 sarcoids, sequences that could be amplified by primers specific for BPV1 and BPV2 were present in 56 cases. This indicates that about 73% of the tested sarcoids contained BPV1 or BPV2 genomic sequences, suggesting a robust association between these viruses and equine sarcoids.
• The team also identified a specific restriction site present in BPV1 and absent from BPV2. A restriction site is a location on a DNA molecule that contains a specific sequence of nucleotides. This feature was found in 28 of the 34 amplified products that were treated with a molecular tool known as an endonuclease – a type of enzyme that cleaves the phosphodiester bonds within a polynucleotide chain.

Implications and Conclusion

• The high prevalence of BPV genomic sequences in the sarcoids underlines a potential role of these viruses in the development of this kind of equine skin cancer.
• The discovery of a specific restriction site distinct to BPV1 provides further ground to differentiate between BPV1 and BPV2 – a key detail considering that different variants of a virus can often associate with different disease presentations.