Opossum DNA map may aid humans
Offers hope for cancer, spine study
NEW YORK -- Scientists mapped the genome of the opossum, an animal best known for eating garbage and playing dead, and the result may open doors to new research on cancer and spinal cord injury in humans.
Opossums are marsupials, animals including kangaroos and koalas that carry their young inside pouches in their skin. By comparing the opossum genome with that of other mammals, scientists can learn more about the common ancestor that roamed the earth about 80 million years ago.
Medical researchers are particularly interested in the opossum's genome because the animal is the only mammal other than humans known to develop melanoma, or cancer of the skin, from light. Also, baby opossums have shown the ability to regenerate a damaged spinal cord, and researchers may want to search the animal's DNA to see if similar processes exist in humans, said Tarjei Mikkelson, the paper's first author.
"That's a major research effort, to understand the molecular basis for this regenerative ability," said Mikkelson, a graduate student at the Massachusetts Institute of Technology, in a telephone interview yesterday.
"It might mean we could learn something that would help us design new drugs or treatments based on these insights."
The research will be published today in the journal Nature.
"You can look at what genes are being turned on and compare that to the severed spinal cord of a mouse," said Eric S. Lander, the founder of the Broad Institute, a collaboration of MIT, Harvard University and its hospital affiliates, and the Whitehead Institute. Lander was a coauthor of the paper.
"Marsupials are telling us 'Wait, wait, it might not be that difficult to regrow spinal cords,' " he said in a conference call to journalists yesterday. "Let's see what tricks our cousins have."
Such treatment is years in the future, Mikkelson said.
The opossum genome also reveals that about 95 percent of the genetic changes between marsupials and humans since the two separated from a common ancestor does not involve protein- producing DNA, Mikkelson said.
