Young Tasmanian devil at the Australian Reptile Park in Somersby.
Credit: Stephan C. Schuster, Penn State University
Tim Faulkner, a breeder at the Australian Reptile Park in Somersby, holds an adult Tasmanian devil that is part of the zoo's breeding program.
Credit: Stephan C. Schuster, Penn State University
Young devil is wrapped up by a handler.
Credit: Stephan C. Schuster, Penn State University
WASHINGTON: By using whole-genome analyses of Tasmanian devils, researchers are formulating a possible plan of action to prevent the extinction of the Australian species.
The furry marsupials have been hit hard by a contagious cancer called devil facial tumor disease (DFTD) that has wiped out 70 to 90% of the population in some areas of its native Australia since it surfaced 15 years ago.
Now, researchers in the U.S. have created a model to predict which individuals would need to be kept in captivity to maximise the chances of preserving enough genetic diversity for the species to survive.
"It acts like a virus but it actually is spread by a whole cancerous cell that arose in one individual several decades ago," said lead author Stephan Schuster, a professor of biochemistry and molecular biology at Penn State University.
"This malignant cell is transferred directly from one individual to another through biting, mating, or even touching. Just imagine a human cancer that spread through a handshake. It would eradicate our species very quickly."
Epidemic could lead to extinction
DFTD, which disfigures the victim and causes death from starvation or suffocation within months, is an unusual sort of cancer that first was observed on the east coast of Tasmania, and since has spread rapidly westward, threatening the species with extinction.
Experts predict the epidemic could render the entire population extinct when it eventually reaches every corner of Tasmanian devil territory by 2016.
For the past several years, conservation specialists have been capturing disease-free devils that could be bred in zoos and released into the wild again once the illness runs its course.
Who are the best candidates?
The study in the current issue of Proceedings of the National Academy of Sciences suggests how to best use data gleaned from the sequencing of the devil's genome - first done by Australian scientists last year - to genetically select a stronger species.
"It's not just a matter of scooping up a few individuals at random and locking them away," said one of the team, Webb Miller, a professor of biology and computer science and engineering at Penn State.
"Our team developed a smarter, more calculated approach: We asked ourselves, which individuals would be the best candidates for 'protective custody,' and what criteria would we use to make those determinations? We soon realised that the answer was to compile genetic data and to analyse it in novel ways."
