June 28, 2011
WASHINGTON (AFP) - Modern conservationists could use gene analysis to better select endangered Tasmanian devils to capture in order to save the species from extinction, said a study on Monday.
The furry marsupials have been hit hard by a contagious cancer called devil facial tumor disease (DFTD) that has wiped out 70 to 90 percent of the population in ome areas of its native Australia since it surfaced 15 years ago.
"Just imagine a human cancer that spread through a handshake. It would eradicate our species very quickly," said Stephan Schuster, a professor of biochemistry and molecular biology at Penn State University and lead author of the report.
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.
The study in Monday's edition of the 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.
While it might seem logical to pick only animals who have the highest innate resistance to DFTD, Schuster said that maintaining some genetic diversity is important to guard against future epidemics.
"You don't want to put out just the one fire -- the cancer. Instead, you want to develop a pool of diverse, healthy individuals that can fight future maladies or even pathogens that have not yet evolved," he said.
To figure out which individuals to select based on their gene profile, scientists sequenced the genome of a devil named Cedric who was born in captivity and exhibited some natural resistance to the cancer before he eventually succumbed to a new strain.
They also analysed the genetic data of a female, Spirit, who was born in the wild and died of the disease, as well as one of her tumors.
Then they compared the recent genetic data to that found in 175 Tasmanian devil specimens in museums.
The data was compiled to create a model to determine which animals to pluck from the wild for a captive breeding program, such as the ones underway in Tasmania and on mainland Australia, the study said.
The theoretical model for species preservation based on genome analysis could extend to other animals in danger of extinction, or about 25 percent of world's land mammals, the researchers said.
