The mission to save our iconic Tasmanian devils is not an easy one, but our team of devils advocates is fighting on, with University of Tasmania Menzies Institute for Medical Research scientists leading the charge.
The Devil Facial Tumour Disease (DFTD), first identified 10 years ago, is a rare kind of transmissible cancer. The disease has decimated the devil population, wiping out 80 percent of our devils. And now routine field research has identified a second cancer affecting devils.
A new foe
Investigations into a possible second cancer began when researchers at the Menzies, who were investigating an apparent case of DFTD, noticed cancer cells that displayed features that were not typical of DFTD. Laboratory studies indicated that the case was a second, and therefore new, type of transmissible devil facial cancer.
Menzies researcher Dr Ruth Pye, who obtained the original samples and performed the initial analysis, said eight cases had now been identified, all from the D'Entrecasteaux Channel area.
This new cancer has similarities to DFTD as it causes tumours, primarily on the face or inside the mouth, and is probably also spread between devils by biting.
The leader of DFTD research at Menzies, Professor Greg Woods, has been working on DFTD for a decade.
Fortunately this new cancer is similar to DFTD and the procedures in place to deal with DFTD will be used to investigate it. The new cancer can be incorporated into the vaccine.
Identifying the new cancer
When the different cancer cells were originally noticed, the Cytogenetics Department of the Royal Hobart Hospital undertook chromosome analysis and established that the case was not DFTD. When a second apparent case of DFTD from the same geographical area was discovered to have the same chromosomal abnormalities, it became likely that this was a new transmissible cancer.
Further chromosomal studies performed at the Animal Health Laboratories, Department of Primary Industries, Parks, Water and Environment, confirmed that the chromosomal changes were different to DFTD.
Thorough genetic analysis performed at the University of Cambridge in the UK provided conclusive evidence that a second transmissible cancer is affecting Tasmanian devils. Dr Elizabeth Murchison from the Department of Veterinary Medicine at Cambridge, said that until now it had been thought that transmissible cancers arose extremely rarely in nature.
It makes us wonder whether transmissible cancers may not be as rare in nature as we previously thought. Alternatively, perhaps Tasmanian Devils are particularly vulnerable to the emergence of transmissible cancers.
Hope for the future
As well as the mission to develop a vaccine, it is also important for the species’ survival to have an insurance population of healthy devils. There are healthy devils in 35 zoos around Australia, as well as wild and semi-wild locations around Tasmania. There are also devils in New Zealand and South American zoos. That’s more than 600 precious, disease-free devils.
Professor Woods said "in the last 10 years we’ve had a number of discoveries. We understand this cancer. We now know a way we can make the devils’ immune system respond to these cancer cells."
A ground-breaking trial releasing the immunised devils back into the wild has commenced. These immunised devils are in areas that DFTD-affected devils are known to inhabit. Despite devastating losses of the re-released devils due not to DFTD but to humans (cars), the herculean effort to save the species continues via this and other projects.
The next three years are critical. We need to improve our vaccine for it to be really effective, and for the devils to require only one vaccination. It’s going to take a lot of scientific research. This has the potential to protect the devils. Not only our generation’s, but generations into the future.
Professor Woods said the support of the Australian Research Council and the Save the Tasmanian Devil Appeal was critical for ongoing work.
The research was primarily supported the Wellcome Trust and the Australian Research Council, with additional support provided by Dr Eric Guiler Tasmanian Devil Research Grants funded from public donations received thorough the University of Tasmania Foundation, Save the Tasmanian Devil Appeal.