An 'immortal' devil's genome and the secrets of a cancer that's catching

Feb 16, 2012
Researchers reporting in the Feb. 17 issue of the Cell Press journal Cell have sequenced the complete genome of one immortal devil. The genomes of the Tasmanian devil and its transmissible cancer may help to explain how that cancer went from a single individual to spreading through the population like wildfire. Credit: Save the Tasmanian Devil Program

Researchers reporting in the February 17th issue of the Cell Press journal Cell have sequenced the complete genome of one immortal devil. The genomes of the Tasmanian devil and its transmissible cancer may help to explain how that cancer went from a single individual to spreading through the population like wildfire.

The deadly transmissible facial cancer has led to the speedy decline of the island-dwelling Tasmanian devil population since its discovery and now threatens the entire species with . Ultimately, the researchers hope that the new findings might point to a way to help save the Tasmanian devils.

"There are targeted drugs that work against cancer genes," said Elizabeth Murchison, a Tasmanian native working at the Wellcome Trust Sanger Institute in the United Kingdom. "We hope some of the that we have found in genes in the devil cancer may point to ."

Tasmanian facial cancer disease is spread from one Tasmanian devil to another through bites that transfer living , and Tasmanian devils bite each other often. The first photograph of a Tasmanian devil with one of these facial tumors turned up in 1996. "At the time, it was thought to be a one-off case," Murchison said.

But soon, dozens more sick devils turned up, and by the early 2000s, "it was clear that this was a new type of infectious disease," she said. The real breakthrough came in 2006 when it was shown that all of the cancers were actually one, passed on clonally from one animal to another. That was a particular surprise because cancer doesn't usually hop from one individual to another, except in very rare instances. Normally, the immune system ensures that foreign cancers cannot survive in new hosts.

In search of answers and potential solutions, Murchison and her colleagues set out to sequence the Tasmanian devil and that of the cancer. Their analyses suggest that the cancer first arose relatively recently in a female Tasmanian devil.

Researchers reporting in the Feb. 17 issue of the Cell Press journal Cell have sequenced the complete genome of one immortal devil. The genomes of the Tasmanian devil and its transmissible cancer may help to explain how that cancer went from a single individual to spreading through the population like wildfire. Credit: Save the Tasmanian Devil Program

"I call her the immortal devil," Murchison said. "Her cells are living on long after she died."

"The cancer genome has evolved as it has spread through the population, but overall it appears to be rather stable," adds Michael Stratton, senior author of the paper. "The genetic differences between 104 tumors from all around the island present us with a remarkably clear picture of how the cancer has spread in time and space over the last couple of decades, which may help with strategies for disease containment."

More than 17,000 mutations in the devil cancer genome have been catalogued, and while that may sound like a lot, it is comparable to the number of mutations found in some human cancers, says Murchison. The task now is to figure out which of the thousands of mutations are most important. Early indications suggest that changes in the immunity genes might ultimately explain how the evades the immune system.

The world has already lost the Tasmanian tiger, which went extinct in the 1930s. "It would be really sad to lose our two largest marsupial carnivores, and within 100 years of each other," Murchison said. Hopefully, the new data will lead to some more definitive answers, and soon.

Explore further: Elucidating extremophilic 'microbial dark matter'

More information: Murchison et al.: “Genome Sequencing and Analysis of the Tasmanian Devil and Its Transmissible Cancer.” Cell, DOI:10.1016/j.cell.2011.11.065

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User comments : 11

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El_Nose
1 / 5 (8) Feb 16, 2012
you want to help them -- pay people to capture infected devils -- stop the spread

or accidentally wipe out the population -- either way they die -- this way you tried to help for the good
dnatwork
5 / 5 (5) Feb 16, 2012
keep some uninfected populations in zoos until the wild ones all die out, then repopulate
Thewise
2.5 / 5 (2) Feb 16, 2012
There is a immortal cancer cell line used for human cancer research, has anyone studied to see if it spreading cancer in humans?
kaasinees
2.1 / 5 (7) Feb 16, 2012
This is the start of the zombie apocalypse.
Thewise
1 / 5 (5) Feb 16, 2012
Thru sloppy researchers in labs, not thru bites. Although this would be interesting as a thriller.
Sinister1811
1.4 / 5 (10) Feb 16, 2012
I don't know why they haven't tried to repopulate the mainland. Or keep a population of devils isolated from the disease.
Graeme
5 / 5 (2) Feb 16, 2012
Sinister1811 - they have got isolated populations on islands.
Sinister1811
1.8 / 5 (10) Feb 16, 2012
Sinister1811 - they have got isolated populations on islands.


Oh, right. I didn't know that. Thanks.
Rohitasch
not rated yet Feb 17, 2012
There is a immortal cancer cell line used for human cancer research, has anyone studied to see if it spreading cancer in humans?

Hela cells. They came from a patient's cervix and now live quite freely as protozoans. Known to be a nuisance in labs, they are not known to transmit cancer.
Shifty0x88
5 / 5 (1) Feb 17, 2012
you want to help them -- pay people to capture infected devils -- stop the spread


You realize they are quite aggressive right? Or were you thinking about professionals?
Eric_B
not rated yet Feb 18, 2012
i bet they would be great for security.