Published on June 27, 2009

Variation in the Same Gene Affects Rate of Parasite Infection in Both Humans and Baboons

Researchers at the Duke University Institute for Genome Sciences & Policy have found that variation in the same gene in humans and baboons produces the same kind of disease resistance.

Humans and baboons share similar evolutionary histories and environments in the East African savanna. Parallel evolution has also been demonstrated in how variation of the Duffy gene affects their respective resistance or susceptibility to infection by malaria parasites. The mechanism is well-known in humans: when the Duffy gene is on, it builds receptors on the surface of red blood cells allowing malaria parasites to land. When the gene is off--there is no infection.
In baboons--there is also a definite link from genetic variation to degree of infection by a malaria-like parasite, but the mechanism is less clear. When the gene is on, more receptors are built, but the incidence of infection is also lower. When the gene is off, the opposite is true.
Credit: Zina Deretsky, National Science Foundation

With support from the National Science Foundation (NSF), lead authors Gregory Wray, Susan Alberts and Jenny Tung drew on Alberts' longtime study of the yellow baboons in Kenya's Amboseli National Park to examine the baboons' susceptibility to a malaria-like parasite and to delve into the genetic basis for differences in the baboons' vulnerability to infection.

Graduate student Jenny Tung did field work over three summers in the East African savannah as part of her doctoral dissertation project, discovering that 60 percent of the Amboseli baboons were infected with the malaria-like parasite.

"It's exciting that this work includes a doctoral dissertation project," said Jean Turnquist, NSF program officer. "These researchers have made a very significant discovery that can only come from this kind of longterm study. It's a great example of seeing the connections between evolutionary genomics and disease susceptibility and resistance."