DNA study reveals intriguing sexual past of African monkey

The most extensive DNA study to-date of Africa’s rarest monkey has revealed that the species had an intriguing sexual past.

Updated: Nov 12, 2009, 13:38 PM IST

Washington: The most extensive DNA study to-date of Africa’s rarest monkey has revealed that the species had an intriguing sexual past.

Of the last two remaining populations of the recently discovered kipunji, one population shows evidence of past mating with baboons while the other does not.

A shy tree-dwelling monkey with a black face and long brown fur, the kipunji was unknown to science until 2003, when it was discovered in a remote region of southern Tanzania.
The first analyses of the animal revealed that kipunji represented an entirely new genus of primate, Rungwecebus.

Now, thanks to additional DNA samples collected from dung and tissue — the most extensive genetic data to date — scientists have a more complete picture of the genetic makeup of this monkey.

The kipunji is found in two tiny forest fragments totaling less than 7 square miles, researchers explained.
Of the last two remaining populations, one is in Tanzania’s Southern Highlands, and the other lies 250 miles away in a mountain range called the Udzungwas.

Armed with six dung samples from the Udzungwas – the first ever genetic material from this population – and two additional tissue samples from the Southern Highlands, the researchers were able to reconstruct the genetic relationships between these populations and kipunji’s closest kin.

Confirming other reports, the Southern Highlands population contained bits of DNA that are similar to baboons.

This suggests that the two species interbred at some point after they diverged, researchers explained.

“Way back in time in the evolutionary history of this population there was at least one event where there was some cross-fertilization with a baboon,” said study author Tim Davenport of the Wildlife Conservation Society.

In contrast, the researchers discovered that the Udzungwa population showed no traces of baboon DNA.

“We thought the DNA from the second population would match the first one, but instead we got something quite different,” said first author Trina Roberts of the National Evolutionary Synthesis Center in Durham, NC.

“We usually think of species’ genomes as being contained and not sharing with each other, but sometimes one species picks up genetic material from another through interbreeding,” said Roberts.

The findings help to settle a debate over kipunji’s status as a new genus of primate.

“They’re still separate taxa — they’re not baboons, they’re still kipunji,” said co-author Bill Stanley of the Field Museum of Natural History in Chicago. “But there’s a little bit of baboon DNA that shows up when you analyze their DNA,” he added.