Vaccine hope for dying Tasmanian devils

Nick Squires, The Telegraph 31 Mar 08;

A Tasmanian devil named Cedric may hold the key to saving his species from extinction.

The animal has shown a robust immune response to the facial tumour disease which has devastated Tasmanian devils over the past decade, wiping out more than half their population.

Cedric is the first of his species found to have displayed immunity from the horrifically disfiguring cancer, known as devil facial tumour disease or DFTD.

Infected animals become so engorged with tumours that they can no longer see or eat, and eventually starve to death.

Tasmanian devils are the world's largest marsupial carnivores and Australians are determined that they are not allowed to follow the thylacine, or Tasmanian tiger, on the path to extinction.

The cancer has spread across most of Tasmania's east coast, where the devils are genetically very similar.

Cedric comes from the island's genetically different west coast population, and was trapped last year.

How and why the disease first emerged remains a mystery.

The discovery that Cedric appears to have a built-in immunity has been hailed as the most important breakthrough in the search for a way to halt the disease's devastating spread.

Scientists hope that Tasmanian devils sharing Cedric's genetic pattern could be resistant to the cancer or capable of responding to a vaccine.

"This is the most exciting thing that has happened in this programme - the devils could be their own saviours," University of Tasmania immunology professor Greg Woods, who works with the Save the Tasmanian Devil project, told The Australian newspaper.

Cedric and his half-brother, Clinky, were injected with dead facial tumour disease cells last year. Clinky produced no anti-bodies, but Cedric did.

Two months ago the two animals were infected with live cells. Scientists expect that Clinky will contract the disease but Cedric, with his different genes, will not.

That would show that devils with Cedric's genetic make-up are resistant to the cancer, or capable of responding to a vaccine.

"It keeps me awake at night," said Dr Woods. "We are really relying on just one devil."

If Cedric proves the researchers right, and remains resistant to the disease, then he will form the basis of a breeding programme to distribute disease-detecting genes to a new generation of devils.

Scientists fear that without major progress in combatting the mysterious cancer, devils could be extinct within a decade or two.

The animals - whose famed ferocity and blood-curdling nocturnal yowls inspired the Warner Bros Looney Tunes character Taz - eat mainly carrion, transmitting the cancer while fighting over food scraps and during boisterous mating.

The mystery disease first emerged on Tasmania's north-east coast more than a decade ago.