Researchers from the Centre for Encephalopathies and Emerging Communicable Diseases of the University of Zaragoza, within the framework of the NEURO-COOP project, have managed to detect prions (PrP^Sc) in the oocytes and ovaries of sheep naturally infected with classical scrapie, using the ultra-sensitive PMCA (Protein Misfolding Cyclic Amplification) technique.

This finding, recently published in the journal Veterinary Research, represents the first direct evidence of the possible involvement of the female germline in the vertical transmission of this neurodegenerative disease, until now considered predominantly horizontal.

The results showed that prion accumulation varies depending on the host genotype (ARQ/ARQ vs VRQ/VRQ) and the outbreak of origin, pointing to a possible influence of the prion strain. Furthermore, it was shown that, although it is not possible to detect prions in ovarian tissue using conventional techniques such as immunohistochemistry, PMCA does allow their presence to be detected, highlighting the need to use highly sensitive techniques for the study of this disease.

These results could have important implications for sheep genetic selection and control programmes, as well as for the design of future scrapie eradication strategies.