Tasmanian devil genome mapping may help humans too

Scientists have mapped the genome of Australia's endangered Tasmanian devil for the first time and found that deadly facial tumours decimating the species evolve very slowly, making it possible help might be found before the animals vanish forever.

Not only that, scientists at Australian National University said on Friday that their discovery, published in the journal PLoS Genetics, could help untangle the process of how human cancers evolve. Tasmanian devils -- popularised by Looney Tunes' fierce cartoon character "Taz" -- are carnivorous marsupials the size of a small dog.

The facial tumour disease has ravaged the wild population, confined to Australia's island state of Tasmania, since being discovered in the mid-1990s. Scientists believe that unless help is found, the wild population could be extinct within several decades.

But the mapping carried out by researchers led by Janine Deakin found that, at the genetic level, the tumours evolve very slowly, making it easier to study them -- and, possibly, circumvent them.

In addition, this may offer an unusual chance to study how human cancers develop, Deakin added. "Because we find the devil tumour is evolving so slowly, we can use that as a model to look at cancers in humans.

It is a bit more like slowing down the whole process in human cancers," she said. "In human cancers the change happens so rapidly we don't have a chance to look into what the mechanisms are. And we can do that with the devil." The Tasmanian devil tumour is spread by skin-to-skin contact and kills by deforming the animals, which then die through starvation or suffocation.

Deakin's team also found that significant fragments of the chromosomes in devils affected by the tumours had been jumbled, like a jigsaw puzzle put together the wrong way.

"One (chromosome) in particular has been completely shattered, which means genes are not in an appropriate order," Deakin said.

That discovery could lead to more avenues of investigation. A previous US study of two Tasmanian devils showed that the population already had low genetic diversity, which likely made them vulnerable to the cancer.