DESCRIPTION (Provided by applicant): The objective of this proposal is to enhance the existing SPF rhesus macaque supply and breeding colony program at the SSFS of the CPRC. This program will use genetically characterized, major histocompatability complex (MHC)-typed, Indian-origin monkeys from established social groups obtained from the CPRC's free-ranging colony on the island of CS. The CPRC will donate the founding stock for the colony, which consists of 102 adult and 21 juvenile females and minimum of 20 sires. Previous surveys have shown that the Cayo Santiago macaques are free of several important viruses including retroviruses, and that the majority of immature animals are negative for B virus. About 20-25% of these monkeys are also Mamu-A*01 positive. Currently, there is a shortage of SPF rhesus monkeys for biomedical research and the demand for these animals is expected to increase dramatically in the future. The establishment and maintenance of this expanded program at SSFS will help meet the increased demand for both SPF (B virus, SRV-D, SIV, and STLV-l-free) and Mamu-A*01 positive rhesus monkeys. MHC-typing and selective breeding will be used to increase the production of SPF Mamu-A*01 positive offspring. The founding cohort is expected to produce a minimum of 70 infants during the first year and an estimated total offspring of about 400 SPF animals in five years. By Year 6 the program should be self-supporting. The CPRC's program will make a significant contribution to advancing biomedical research, and in particular to AIDS research by providing high quality and healthy SPF rhesus monkeys to NIH-sponsored research programs.