Friday, August 11, 2006

Friday Animal Blogging, Sort Of...

Well, I don't have any animals of my own to share today, so instead I'll direct you to Carl Zimmer's post on a newly discovered parasite that causes cancer in dogs. Here's the catch: The parasite is actually the cancer cells themselves; they've adapted to transmitting themselves sexually from one dog to another. That is just plain freaky, given that we have an example of what appears to be cancer cells turning into their own organism with their own evolutionary trajectory. This particular cell line has been moving from dog to dog for at least a few centuries, possibly longer.

"So here's the big question which the authors don't tackle head on: what is this thing? Is it a medieval Chinese dog that has found immortality? If so, then it resembles HeLa cells, a line of cancer cells isolated from a woman named Henrietta Lacks who died in 1951. After her death, scientists have propagated her cells, and in that time they have have adapted to their new ecological niche of Petri dishes, acquiring mutations that make it grow aggressively in the lab. One biologist even suggested that the cells should be consider a new species.

Sticker's sarcoma has, without any intervention from scientists, become a cell line as well, and one that has survived far longer than HeLa cells have. It is distinct from its dog ancestors, and has acquired adaptations that allow it to manipulate its hosts for its own advantage as effectively as a virus or a blood fluke. A parasite evolved from a dog, perhaps."

Thus spake Zimmer.

Next week I'll try to return to normal Animal Blogging, assuming I can find some animals out here that aren't prairie dogs.