New Source For Lab Monkeys

Rhesus macaque monkeys from India have helped scientists develop treatments for many diseases, but researchers are now faced with a critical shortage of the primates in the laboratory. A new genetic study suggests that rhesus macaques in Nepal might provide a suitable alternative in work to develop vaccines against diseases such as HIV/AIDS.

India banned the export of all Rhesus macaques in 1978, which lead to the current shortage. Although researchers have imported macaques from China for sometime, scientists have noticed a number of behavioral and physiological differences in disease progression between animals from the two countries. The rhesus macaque is abundant in many countries and is not considered an endangered species.

Finding a suitable replacement for current lab monkeys is important as macaques of Indian origin have been used for more than half a century in biomedical and behavioral research. Rhesus macaques have contributed to the discovery of vaccines to prevent diseases such as polio and yellow fever and are one of the most widely used primate models for AIDS-related research.

Randall Kyes, a primatologist at the University of Washington, and colleagues compared blood from 21 Nepali rhesus macaques living at a temple site in Kathmandu to samples from more than 300 Indian- and Chinese-origin rhesus macaques. The researchers analyzed DNA genetic variations across 17 chromosomes. They also looked for the presence of genes that are known to influence immunity and the rate of disease progression in the animals, including one that is present in Indian rhesus macaques but not in the Chinese ones.

To facilitate the use of rhesus macaques in research while ensuring the conservation of Nepal's naturally occurring rhesus populations, the Nepali government enacted a policy in 2003 stipulating that only captive-bred animals may be used for scientific research. An agreement between the Nepal Biodiversity Research Society and the Washington National Primate Research Center was signed in September 2003.

"This program will not harm the natural populations because we will establish the self-sustaining breeding colony with a relatively small number of animals that will be acquired from areas of known human-monkey conflicts," Kyes said. "In Nepal, this conflict is caused by monkeys that raid staple crops such as sweet potatoes and corn. Crop raiding is prevalent in many areas in Nepal and in the last five to 10 years there are many instances of local people seeking to solve this problem by chasing or killing macaques."

A captive-breeding facility is now under construction, and researchers hope to establish a breeding colony within 12 months. One of the goals of the program will be to address some of Nepal's most pressing health concerns, which include HIV, tuberculosis, hepatitis, and malaria.

The study, which was supported in part by the National Institutes of Health, is detailed in the current issue of the American Journal of Primatology.