Close relationship between equine and human molluscum contagiosum virus demonstrated by in situ hybridisation.

The research article is about a study conducted to determine whether the same virus causes a specific skin disease, molluscum contagiosum, in both humans and horses. This was done through hybridisation experiments, and the findings suggested a very close or possibly identical virus affects both species.

Objective of the Study

• The research aimed to investigate if the virus that causes the skin disease molluscum contagiosum in humans is the same one causing a similar disease in horses. This was done using advanced biomedical techniques, including in situ hybridisations using human molluscum contagiosum virus (MCV) DNA.

Methods Used

• In situ hybridisation experiments were conducted using cloned fragments of human MCV DNA. This DNA was labelled with digoxigenin, a steroid used as a marker in biological research.
• The tests were carried out on biopsy sections taken from lesions of two horses that showed symptoms resembling molluscum contagiosum.
• The experiments were carried out under high stringency conditions that involve high temperature and low salt concentrations to ensure specific binding between probe and target sequences.

Findings and Conclusions

• In both cases, specific hybridisation of the labelled probe to target DNA was observed in the tested sections, as evidenced by the development of a deep blue-purple stain in certain cell layers of the skin lesions.
• This stain was not present in adjacent non-lesional areas of the skin, indicating that the reaction was specific to the lesion tissues affected by the disease.
• The results point to either an identical or very closely related virus being the cause of molluscum contagiosum in both humans and horses. This conclusion is based on the very close homology observed in their viral DNA sequences.