that the genome of the agent could vary independently and, although replicated by normal host mechanisms, was not coded by the host. The term 'virino' was coined to reflect the small size, immunological neutrality, and virus-like nature of the infectious particles. Thus, in the nucleotide model proposed by Dickinson, AG, and Outram, GW in 1979, the lifecycle of the scrapie agent included a stage where the genome was bound to host protein, probably a multimeric protein complex, derived from the sinc gene. Recalling Enrico Fermi's word play on a neutron-like particle, Outram coined the term 'virino' to describe a small virus. In the virino model, the host protein protects the scrapie agent nucleic acids from degradation and prevents the host from raising an immune response, since the protein/nucleic acid complex is seen as a legitimate part of the host. However, the presumed scrapie-associated nucleic acid has not been identified, and physical or chemical evidence for its presence is lacking. References Obsolete scientific theories