Determination of genetic status in a closed colony of rhesus monkeys (Macaca mulatta).

The long-term management of breeding colonies requires some measure of genetic diversity in the animal population. For the maintenance of breeding colonies of monkeys used for biomedical research, known pedigrees supply precise data to determine the genetic status of colonies. We present data of genetic analyses in an old closed colony of rhesus macaques (Macaca mulatta) that was established in 1932 with 100 animals. For more than 40 years, the animals were kept on an isolated island and, in 1980, single-male breeding groups were established. A total of 333 DNA samples of these animals were typed to 20 microsatellite markers using multiplex PCR in order to verify inbreeding coefficient (alpha) and level of heterozygosity. We found an average heterozygosity of 64% and obtained alpha=-0.03293 (+/-0.00573). Our results indicate that the reproductive strategy used was effective because consanguineous breeding was avoided. A continuous genetic program must be carried out in order to obtain better quality primates for biomedical research.

Prevalence of antibodies to selected viruses in a long-term closed breeding colony of rhesus macaques (Macaca mulatta) in Brazil.

The rhesus macaque breeding colony of the Oswaldo Cruz Foundation (FIOCRUZ) was established in 1932 from a founding stock of 100 animals. This population has remained closed to new animal introductions for almost 70 years. A serologic survey was performed to determine the prevalence of antibodies to selected viruses as a first approach to identifying viral pathogens endemic in this population. Banked serum samples were tested for antibodies to simian immunodeficiency virus (SIV), simian T-lymphotropic virus (STLV), simian type D retrovirus (SRV), cercopithecine herpesvirus type-1 (B virus), rhesus cytomegalovirus (RhCMV), measles virus (MV), and hepatitis A virus (HAV). All samples were negative for antibodies against the simian retroviruses. The overall prevalence of antibodies was 95% for RhCMV, 45% for B virus, 35% for HAV, and 1% for MV. Prevalence was found to vary by age group.