Core C - MHC Genetic Typing Core: Project Summary Rhesus macaques (Macaca mulatta) are a vital non-human primate (NHP) model for the study of infectious disease and are in critically high demand for biomedical research studies. The expanded Specific Pathogen Free (eSPF) colony at the Oregon National Primate Research Center (ONPRC) is an essential resource for the production of model macaques free from an extended list of pathogens capable of confounding the study of human immunodeficiency virus and the related simian immunodeficiency virus (HIV/SIV) pathogenesis. These purpose-bred animals are crucial for meeting the growing demand for NHP research animals and to facilitate advancements in human health. Accurate and comprehensive genetic analysis of the eSPF colony is essential to its long-term health and the continued productivity in generating valuable research animals. Of critical importance is the genotyping of the major histocompatibility complex (MHC) which can strongly influence host response to infection and must be accounted for in study design and data analysis. MHC loci are highly polymorphic and structurally complex, requiring specialized assays and analysis procedures for accurate and comprehensive genetic characterization. The MHC Genetic Typing Core (Genetics Core) is responsible for genetic testing and analysis of the eSPF colony and works closely with individual investigators and the Husbandry and Management Core to ensure that research and colony management needs are met. Additionally, the Genetics Core assays genetic variation within the population using multiple metrics to promote adequate genomic diversity through the use of parentage confirmation, ancestry testing, and the genotyping of specific pathogenic variants or alleles capable of influencing pathogenic response. ONPRC is a leader in the development and use of genomic technologies in NHP research and the Genetics Core will utilize state-of-the- art tools and incorporate the use of novel resources to support the goals of the eSPF colony.