We found that the newly-formed strains in hamsters (139A-ha and ME7-ha) obtained new molecular and biochemical features that were similar as that of the hamster-adapted scrapie agent 263 K. Meanwhile, we confirmed again that the appearances of scrapie-associated fibrils (SAF) and proteinase K (PK) resistant PrP in brains infected with agent 139A and ME7 were much earlier than the emergence of clinical manifestations. Here, PRNP is linked to scrapie.