14 DAY TRIAL // In recent years, scientists have taken a deep interest in Tasmanian devils. More than 70 percent of the population living in the wild has perished on account of a strange disease, which was cataloged as a form of cancer. For quite some time, experts were in the dark as to where this infection came from, and what precisely caused it, but a new work sheds some light on this issue. Apparently, the main culprits behind the spread of the cancer are cells that normally envelop nerve fibers in an insulating coating, Wired reports.
The condition, which is called the devil facial tumor disease, has the ability to eradicate the entire Tasmanian devil population living in the wild by 2040-2060. At the current rate of population decline, these numbers are highly realistic, experts say. A new paper, published in the January 1 issue of the top journal Science, reveals that the troublesome cells became cancerous in a single individual, but that they were transmitted to others as well. When an infected individual bites a healthy one, the disease is transmitted, and so on. The situation is made even worse by the fact that most devils tend to bite each other on the face, the experts add.
In a new set of investigations, it was determined that the original devil that developed the infection lived more than 20 years ago. The researchers behind the study analyzed 25 tumors in just as many individuals, and determined that the genetic makeup was identical in all cases, which is a clear indicator of a single source. The work was conducted by Howard Hughes Medical Institute investigator Gregory Hannon, from the Cold Spring Harbor Laboratory, in Long Island, and Wellcome Trust Sanger Institute postdoctoral researcher Elizabeth Murchison. “I didn’t want to sit back and let the devils disappear,” Murchison reveals. Hannon says that a vaccine for the Tasmanian devils may be devised within ten years, which would leave scientists with enough time to save the devils.
One of the main reasons why the disease is so easily transmittable is the fact that the genetic material in Tasmanian devils is very similar within all individuals. This means that their immune systems do not recognize cancerous cells as foreign, and therefore do not mount a response against them. Schwann cells, which generally insulate nerve cells, were found to be the main culprits behind the infections, but precisely how they became contagious is still a mystery. “Devils are known to be prone to cancers. I think it was just some sort of freak of nature that allowed this cancer to be stable and transmitted,” University of Sydney geneticist Katherine Belov, who has not been part of the new work, says.