Atlanta ? Primate expert Jane Goodall and 18 other researchers sent a letter to federal officials urging them to oppose an Atlanta research center’s proposal to do AIDS-related research on sooty mangabey monkeys.

The letter urges the U.S. Fish & Wildlife Service to reject a request by the Yerkes National Primate Research Center, according to a copy filed with the government.

Scientists at the research center have nurtured a group of the primates, which are natural carriers of a form of the AIDS virus but don’t get sick from it, since the late 1960s. But federal officials listed them as endangered in 1988, leaving the center with the world’s largest collection of captive sooties but little hope of scientific benefit.

The research center argues that its mangabeys, a subspecies of the endangered white-collared mangabey, aren’t truly endangered. It is asking Fish & Wildlife to consider the subspecies separately.