Tasmanian Devil’s genes evolving – Becoming resistant to cancer

A genetic study of Tasmanian devils has uncovered signs that the animals are rapidly evolving to fight back against an infectious face cancer. An global group of researchers made up of scientists from the USA, U.K., and Australia, described their findings in the journal Nature Communications, published on August 30.

Emblematic nocturnal marsupials from Tasmania, an island southeast of Australia, this carnivore was struck in 1996 by the fatal Devil facial tumour disease (DFTD), nearly 100% fatal.

The team found five genes spread across two regions of the genome that seemed to be increasing in frequency throughout the devil populations. But if the results hold up, they would show that evolution can happen with blazing speed even in complex animals.

Tasmanian devils are the largest carnivorous marsupials.

The infectious tumors threaten to wipe out the small, fierce marsupials, but genetic analysis shows rapid evolution may come to the rescue.

The animals may able to pull themselves off the fast track to extinction-with some help from evolution. The DFTD is a contagious disease that was first reported 20 years ago.

The researchers report that such a rapid evolutionary response to a highly lethal, newly arrived pathogen has rarely, if ever, been documented in wild species, and say it could explain how the Tasmanian devil has held out for so long against such a quickly spreading, lethal disease.

It is not likely that genetic changes would afford Tasmanian devils complete resistance to cancer, but it may give them sufficient time to reproduce.

The Tasmanian devil is found throughout the island state of Tasmania, Australia, although fossil evidence suggests that it once occupied much of the Australian mainland.

The researchers hope their findings can be used to develop new strategies to help increase resistance in captive populations of Tasmanian devils too.

“This research provides support for vaccine research as devils appear to respond to the tumours”, Woods said.

“This gives us hope for the survival of the Tasmanian devil”, Storfer said. And two, it’s the unfortunate carrier of a nasty transmissible form of cancer-one that causes deadly facial tumors. They occupy several different dens, changing dens every 1-3 days, and traveling a mean nightly distance of 5.6 miles (9 km). Since the scourge first appeared in 1996, the critter’s population has crashed by 80 percent. Known for biting each other on the face during encounters, this activity created the ideal situation to transmit the infection as quickly and efficiently as possible.

Storfer said the next step was to try to figure out exactly what those genes do in Tasmanian devils.

“It is really remarkable, the fact that we are able to use this modern sequencing technology to find these needles in a haystack across the genome”, says Paul Hohenlohe, a genomicist at the University of Idaho and one of the study’s co-authors. This mostly has to do with the immune systems of advanced organisms-while our own cancer evades immune responses by virtue of being, well, part of us, cancer from other individuals is recognized as an invader. But how protective the variant is against the disease is still unclear.

Using a rapid scanning method, the team examined portions of the genomes of almost 300 animals, from three separate locations across Tasmania.