Tasmanian Devils saved by genes?

Australia’s Tasmanian Devil population has been in freefall due to a virulently infectious cancer; and it is predicted that this unique species may be wiped out within three years. The disease, which appears as facial lesions, is spread by biting during mating and is one of only three communicable cancers which exist in the world.
Scientific research into major histocompatibility complex (MHC) – which activates an immune response in vertebrates – has shown that the devils have little genetic diversity which means that their immune systems do not treat the tumour cells as a threat. However, scientists are focusing on the more isolated devils from the west of Tasmania (as opposed to the common eastern variety), which appear to have a different MHC type. Researchers have only uncovered one devil that resists the disease, and tests showed he had a different MHC type from the eastern devils. When injected with dead tumour cells the devil’s immune system began to fight the tumour. The devil was then injected with live tumour cells and, at the present, is still healthy. Now, 6 devils are being injected with live tumour cells in an attempt to find resistant animals that can be bred. The tumour is unlike any other disease of its kind, but it seems natural that resistant devils ought to exist (scientists pin their hopes on the tumour obeying this ‘rule’). If the 6 devils prove resistant scientists plan to breed them back into the wild and into captive populations, improving the species’ immunological fitness.
As the genetic detective work continues into this disease, and the Tasmanian devils’ potential to genetically resist the tumour is uncovered, devils are being ‘stockpiled’ in zoos and wildlife parks in order to implement a massive breeding program when the secrets to the disease are uncovered. Meanwhile, other avenues to solve the disease are being explored. For example a number of scientists are seeking financial support to sequence to devil genome, and some ecologists suggest a scheme to fence off areas in Tasmania to establish new devil colonies or even create devil populations on mainland Australia. However, if the 6 devils achieve resistance, these measures may not be required.

(Source: TIME Magazine, May 19, 2008, pg 44)