We performed fly-to-mouse transmission experiments in order to detect bona fide prion infectivity accumulation in scrapie-exposed ovine PrP Drosophila. In these experiments, aliquots of the same head homogenate prepared from flies used as seed in the PMCA experiment described above was inoculated into the tg338 mouse line, which is transgenic for VRQ ovine PrP. Here, PRNP is linked to scrapie.