Mystery of Tasmanian devil tumour deepens - for now

Jun 07, 2012
A Tasmanian devil with Devil Facial Tumour Disease. Credit: Rodrigo Hamede, University of Tasmania

(Phys.org) -- The degree of genetic difference to a tumor is not a factor in Tasmanian devils contracting the facial tumor disease, according to research led by the University of Sydney.

The finding, published today in PLoS One, the journal, surprised researchers and means they will take a different approach in the race to better understand the Devil Facial Tumour Disease (DFTD), a contagious cancer which has already wiped out 85 percent of all .

"We looked at the West Pencil Pine population, in north-western Tasmania because they are the first population to be less severely affected by DFTD than other populations," said Associate Professor Kathy Belov, the senior author of the study from the University's Faculty of Veterinary Science.

In West Pencil Pine there is lower prevalence of the disease, increased survival time of infected individuals and little indication of changes in or population growth rate, four years after the disease was first detected.

"We thought that differences in certain key immune genes might explain the different susceptibility patterns between devils in West Pencil Pine and other devils," Professor Belov said.

Due to devil populations having low most Tasmanian devils share the same Major Histocompatibility Complex (MHC) genes as tumours. The researchers believed that since the tumours were genetically similar to individual devil's own cells their immune system wouldn't recognise that the were foreign and wouldn't attack them.

"Many of the devils at West Pencil Pine are genetically different to the animals in the east of the state. We thought these genetically different animals might be able to mount an immune response against the tumours," Professor Belov said.

"We thought devils that were most genetically different to the tumours would be less likely to catch DFTD. This isn't the case."

The researchers will have to go back to the drawing board to try to work out why DFTD is affecting genetically different devils.

"It is possible the tumor itself is suppressing the immune response in some way. We also know that DFTD is evolving and changing over time. Perhaps the strain of DFTD in West Pencil Pine is different and that is why fewer animals are getting sick in that region," Professor Belov said.

The next step will be to look more closely at the tumors in West Pencil Pine and at across the entire devil genome, rather than simply focusing on the . West Pencil Pine may still hold the key to why some devils catch DFTD and others do not.

The other contributing authors to the paper include Dr Amanda Lane, Yuanyuan Cheng, Belinda Wright, Dr. Laura LeVan and Dr. Beata Ujvari from the University of Sydney and Dr. Menna Jones and Dr. Rodrigo Hamede from the University of Tasmania.

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tthb
not rated yet Jun 07, 2012
maybe move a few up to a higher lat., . . .
tthb
5 / 5 (1) Jun 07, 2012
maybe it's too many of something else around, for what they ARE up to; God help them, too
Jonseer
1.7 / 5 (3) Jun 07, 2012
Typical of Australian efforts to "save" their unique wildlife. Dithering, unfocused in no hurry as the population dwindles. The sheer incompetence of their efforts is breathtaking. These assumptions are based on what? If they were so confident, why not try it in the lab, instead of allowing it to spread in the wild, then try to counter it after they start dying.
Sherrin
3 / 5 (2) Jun 08, 2012
Jonseer - just how much do you know of what is actually going on in the effort to save the Devil? Devils free of the disease are quarantined in various locations, with mainland sites being considered as well. Australian scientists are racing to find a solution, but science is poorly funded by Australian governments due to a lack of science-qualified politicians and a generally ignorant, self-interested public (I'm gettin' the latest iPhone mate; science is for nerds, etc etc).
dontknowmuch
not rated yet Jun 08, 2012
When I visited the Tasmania Zoo (near Launceston)last year, they told us all about their efforts ~ that they already have zones and habitats set up on the mainland as well, and that even with their best efforts- that they would still require around 20 ~30 per community to repopulate a pack, and at the moment they simply couldn't locate enough healthy ones to put in each separate zone- and that they ultimately expected them to be completely gone within five years.