2007 Annual Report 1a.Objectives (from AD-416) To identify and differentiate typical and atypical case samples of CWD and Scrapie by characterizing the biologic phenotype and pathologic profile of these agents when administered to susceptible lines of transgenic and inbred mice. 1b.Approach (from AD-416) Tissue samples from deer, elk, sheep and goats with Transmissible Spongiform Encephalopathy (TSE) will be administered to mice by intracerebral injection. Multiple tissue types will be included, such as samples of brain, lymph node, blood, urine, feces, antler velvet and muscle. Mouse models used as recipient hosts will include both preexisting and recently created transgenic and inbred mouse lines. Recipient mouse phenotype will be evaluated by measuring clinical response, population disease rate, incubation time, and pathologic profile within the central nervous system (CNS). Pathologic profile of CNS lesion foci is assessed by evaluating anatomic localization, spongiform change, astrocytic gliosis, and deposition of protease resistant prion protein. BSL-1; 9-4-06. Documents SCA with U. of WA. 3.Progress Report This report serves to document research conducted under a specific cooperative agreement between ARS and the University of Washington. Additional details of research can be found in the report for the parent project 5348-32000-026-00D Transmissible Spongiform Encephalopathies: the role of genetics, strain variation, and environmental contamination in disease control. The purpose of this new SCA is to identify and differentiate typical and atypical case samples of CWD and scrapie by characterizing the biologic phenotype and pathologic profile of these agents when administered to susceptible lines of transgenic and inbred mice. There will be weekly interactions between the ADODR, ADRU scientists and University of Washington collaborators through personnel visits, conference calls and emails.