Baboon genes help fight parasites - June 25, 2009
Posted for Erika Check Hayden
Some baboons are born with an in-built resistance to a malaria-like disease, scientists have found. It is the first known example of a genetic variant in a non-human primate species that is correlated with a complex trait — in this case, resistance to a parasitic disease.
Like ancestral humans, baboons are large-bodied primates that roam the grasslands of East Africa. The research reveals that both groups have evolved similar solutions to fighting off malaria parasites that are common in that region.
"Our study suggests that looking at genetic differences between non-human primates may help us learn more about the possible solutions that evolution has come up with for us to cope with these sorts of things," says Jenny Tung, a graduate student at Duke University in Durham, North Carolina, who conducted the research with Gregory Wray, also of Duke, and Susan Alberts of Duke and the Institute of Primate Research at the National Museums of Kenya in Nairobi.
Tung's team studied baboons in Kenya's Amboseli National Park. They first analysed blood samples taken from baboons there as far back as 1971, looking for evidence of infection with Hepatocystis kochi, which is related to the Plasmodium parasites that cause malaria in humans. They then spent four years collecting new blood samples from the baboons, measuring RNA levels of a particular gene FY (DARC) whose expression is linked to malaria resistance in humans.
The team found that genetic variation in one section of the FY gene in baboons helped to determine how strongly that gene was expressed, and also the baboons' susceptibility to H. kochi infection. The region of DNA around the FY gene also bears the signature of natural selection, the team reports this week in Nature.
Scientists have studied the behaviour, demography, physiology and life history of non-human primates for decades, but very little is known about genetic variation within non-human primate species. Tung says her work shows the potential value of such studies: "This is opening the door to a new area of field research on primates."
Image: study population members at rest / Jenny Tung
