Tasmanian Devil immune system fails to fight cancer

SYDNEY, Oct 8 (Reuters) A lack of genetic diversity in Australia's Tasmanian Devil means it has failed to launch an immune defence response to a facial cancer decimating populations, Australian researchers say.

The facial cancer produces large tumours on the face and neck of the Tasmanian Devil, found only on the southern Australian island state of Tasmania, which interfere with feeding. Death usually occurs within six months.

The Tasmanian Devil is a carnivorous marsupial about the size of a small muscular dog. It has black fur, gives off a skunk-like odour when stressed, and earns its name for its ferocious temperment and disturbing call.

''We found that the Devils do not mount an immune response against the tumour,'' said Katherine Belov from Sydney University's School of Veterinary Science.

''Essentially, there are no natural barriers to the spread of the disease, so affected individuals must be removed from populations to stop disease transmission,'' said Belov.

''Loss of genetic diversity in these genes just opens the door for emergence and rapid spread of new and old disease,'' Belov said in a statement on the Tasmanian Devil research.

The study also found that the facial cancer was genetically identical in every animal and had originated from a single contagious cell line, spread throughout the population by biting during fights for food and mates.

The Tasmanian Devil faces extinction in 10 to 20 years due to the facial cancer, the report said.

The research by Sydney University, the University of Tasmania, the Australian Museum and the Tasmanian government was published online by the Proceedings of the National Academy of Sciences of the United States of America.

REUTERS ARB RN1212