PRNP and variant Creutzfeldt-Jakob disease: The survival data described above indicated that vCJD prions propagated equally efficiently in M129 and V129 human PrP Drosophila. This contrasts with the transmission of vCJD prions in transgenic mice homozygous for Val129 human PrP which occurs in a restricted manner and is coupled with the emergence of a prion with distinct strain features (52).