November 23, 2012
Researchers Find Bornean Elephants Have Low Genetic Variability
Lee Rannals for redOrbit.com — Your Universe Online
A research lab has identified the genetic markers for an endangered species of elephant, showing the animals have very low genetic variability.The study, published in the journal PLoS ONE, opens up new avenues for the conservation of other endangered species.
Researchers took advantage of DNA sequencing methodology in order to try and change the odds when looking for diversity.
The Bornean elephant is a unique subspecies of the Asian elephant, and in the past scientists had limited genetic tools available to study its genetic variability. However, with new tools, researchers used two different DNA sequencing technologies to identify the genetic markers.
These technologies have been used for common laboratory species like mice and fruit-flies, but they are only now starting to be used on endangered and "non-model" species.
In the past, researchers had to look through huge regions of the genome in order to determine whether the species still harbored sufficient genetic diversity. This approach can be unsustainable for the endangered species, and the only approach to try this on the Bornean elephant in the past resulted in no found genetic diversity. However, researchers in the latest study beat the odds.
With the researchers approach to the Bornean elephant, scientists will be able to find those needles in the haystacks needed to confirm genetic diversity.
The scientists reported that they are confident that these DNA sequencing methods can be used to categorize other biological samples more easily, even though blood or tissue samples are necessary to identify the markers during the first steps.
"The methodology applied to identify the genetic markers for the Bornean elephant can be used in the future for studies on the genetic variability of other species or populations facing the risk of extinction," Reeta Sharma, first author of this work, said in a statement.
The elephants live in an environment where natural habitats disappear fast due to oil palm plantations, and populations are getting isolated from each other. These genetic markers will help scientists to identify populations that are isolated and genetically depauperate, and monitor them in the future.
The only study done on the basis of genetic data in the past found that these elephants had been present in Borneo for more than 300,000 years. However, not all scientists agree with this theory, because of a lack of fossils to support it.
Another theory claims that the sultan of Java sent Javan elephants as a gift to the sultan of Sulu, who would have introduced them to Borneo.
"The new genetic markers that we found may also allow us to unravel the mystery of the origin of these elephants in Borneo, and perhaps reconstruct part of their demographic history. This is very exciting," Lounes Chikhi, a group leader at the Instituto Gulbenkian de CiÃªncia, said in a statement.