While the Tasmanian devil has been known to be plagued with this unusual cancer that can be spread from animal to animal, researchers have recently discovered the endangered species suffers from two forms of the contagious disease.
Tasmanian devils (
Sarcophilus harrisii) are marsupials, and like kangaroos and opossums; females have pouches to carry and suckle newborns. At one time, the dog-sized marsupials were spread across the Australian mainland, but about 400 years ago, they disappeared and are now confined to the island of Tasmania, about 150 miles (240 kilometers) south of Australia.
After the disappearance of the Tasmanian tiger or
Thylacinus cynocephalus, in 1936, the Tasmanian devil became the world's largest living
carnivorous marsupial. Well known for their disturbing screeches, offensive odor, and viciousness while eating and mating, the devil was considered a pest by farmers and readily killed until they were granted protection in 1941.
Thylacine family at Beaumaris Zoo in Hobart, 1910.
Unknown
Discovery of devil facial tumor disease
Since the discovery of
devil facial tumor disease (DFTD) in 1996, scientists have learned the disease is one of only four contagious cancers known about to date, including forms have been identified in dogs, soft-shell clams, and Syrian hamsters. These cancers arise when the cancer cells develop the ability to spread beyond the host's body to the body of a new host.
In 2012, geneticist Elizabeth Murchison of Cambridge University, while comparing the DNA from different individuals, discovered the original tumor came from a single individual female. Now, Murchison and Gregory Woods, with the University of Tasmania have identified a second, and distinct cancer, one with Y-chromosomes, meaning it originated from a male Tasmanian devil. To date, eight Tasmanian devils have been found to have this second form of DFTD.
Other than the distinction in the DNA mapping of the tumor, the
external symptoms of the two tumors are indistinguishable. DFTD is characterized by cancerous tumors that grow around the face, mouth and neck. Once symptoms become visible, the outlook is bleak, with death coming within six months.
The study, "
A second transmissible cancer in Tasmanian devils," was published in the journal
Proceedings of the National Academy of Sciences on December 28, 2015.
