"Major Advance in Understanding of the Devil Disease - February 2006
DPIW’s scientific team published ground-breaking research on the Tasmanian Devil Facial Tumour Disease (DFTD) in the world’s pre-eminent peer-reviewed science journal, NatureYou are now leaving our site. DPIWE is not responsible for the content of the web site to which you are going. The link does not constitute any form of endorsement. The paper, written by DPIW’s senior cytogeneticist Anne-Maree Pearse and her assistant, technician Kate Swift, has been described as being of global significance.
The paper establishes with a high degree of certainty that devil facial tumours are clones transmitted by allograft. Allograft is where tissue is transplanted from a donor of the same species, but with a different genetic make-up, without the recipient’s immune system rejecting the graft. This is usually an exceptionally rare occurrence.
The paper states that the cancer is infective. The infective agent is a rogue cell line that initially evolved in a tumour of unknown origin.
The chromosome arrangement of all the tumours is identical. All show exactly the same complex rearrangement of their chromosomes, unlike virtually all other cancers.The chromosomes of the cancerous cells do not exhibit similarity with the healthy cells elsewhere in the bodies of the infected devils. This means that the DFTD sarcoma can be described as a clone capable of parasitic existence in the body of Tasmanian devils.
The growing scientific acceptance that the infective agent is a rogue cell-line passed between devils by allograft has implications for control and suppression of DFTD.
The paper reinforces the correctness of the Department’s approach to directly intervene in the field to keep sick devils away from healthy ones through insurance populations in quarantine areas and also in the trials to suppress DFTD in the field. It provides a high degree of confidence that keeping healthy animals away from sick ones is sufficient to prevent infection.
There are significant practical challenges in attempting to keep sick and healthy devils apart in the wild, and the field trial now underway on the Forestier Peninsula may help provide some of the answers."
Another website.
http://abc.net.au/rn/scienceshow/stories/2006/1559962.htmAnd another.
"DEVIL FACIAL TUMOUR DISEASE - Anne-Maree Pearse, Launceston Mount Pleasant Laboratories, Tasmania
Chris - For the past few years, people have been noticing something horrible happening to an animal called a Tasmanian Devil. This is the world's only carnivorous marsupial, and they have some nasty habits, such as biting each other. They've been developing horrible facial tumours that eventually kill them by preventing the Devils from eating properly. Nobody knew where these tumours were coming from or what was causing them. But now they think they know, and what's really spine chilling about this is that it looks like this is an infectious cancer that one animal can pass to the next.
Anne-Maree- It became very clear about three years ago that the Tasmanian Devil's numbers were in great decline and they were in decline because they were dying of Devil Facial Tumour Disease. It generally starts around their mouths or around their lips and grows from there. Devils have the most disgusting behaviour. They fight over everything and they bite each other around the face. In other words they sort of jaw wrestle. These tumours are occurring where these wounds are more or less. They get very large and eventually the devils die, generally of starvation because they're unable to feed.
Chris - So the fact that you've got an injury on one devil which then turns into a tumour, and it's inflicted by another devil kind of suggests that this must be some kind of infectious phenomenon.
Anne-Maree - Yes. Normally in tumours you will find a common cytogenetical or chromosomal break point which actually defines the disease. I expected to find this in the devil with various random rearrangements around it. When I looked at them they were just totally rearranged. It was a massive amount of rearrangement. I looked at the next animal and it was exactly the same, and there were no sex chromosomes in animals of either sex. When you get something as complicated as the mix up in these chromosomes in this cancer, and when you can't find any sex chromosomes in the cancers in animals of either sex, you start to think that you've got an infectious cell line.
Chris - But this raises the obvious question, if you can transmit tissue from one devil to the other, that's almost analogous to an organ transplant. So why isn't it rejected? Why doesn't the devil's immune system just kick in and get rid of the hostile tissue?
Anne-Maree - Well this is another part of the puzzle. The devils' immune system isn't doing it. We know that either the cell line itself or the infectious cell line is capable of sliding under the devil's immunological radar, or that there's something wrong with the devils' immunity.
Chris - Is this the first time that anyone's spotted a disease like this, or are there other examples?
Anne-Maree - There is an infectious dog tumour, a canine venereal sarcoma, which is believed to be spread that way. There is a difference between it and the devil disease, which is that the dog's immune system can overcome it, and it regresses.
Chris - So to what sort of extent is this affecting devil populations in Tasmania? Is this restricted to a small part of the population or is it having a major impact?
Anne-Maree - We're talking about a major impact. The devils are affected in slightly over 50% of the Tasmanian mass, and it seems to be spreading.
Chris - And is there any chance of curing it?
Anne-Maree - We've had no attempts at curing it because you can't catch every devil in Tasmania and give it chemotherapy. But wouldn't it be lovely if we could find a vaccine?"
But the disease can do MAJOR damage to the numbers of a population, playing a large role if the species ever goes extinct.