An Alaskan malamuteWIKIPEDIA, SCMWThousands of years ago, a tumor cell from the genitals of a dog evolved into an immortal, free-living parasite. Rather than dying with its host, it gained the ability to spread from one dog to another through sexual contact. This contagious cancer, now known as canine transmissible venereal tumor (CTVT), has spread to dogs all over the world, and it is the oldest known cell line in existence.
Now, a team of scientists led by Elizabeth Murchison at the University of Cambridge has sequenced the genomes of two CTVTs. Their results, published today (January 23) in Science, show that this extraordinary cancer first arose around 11,000 years ago. From its genes, the team could even tell that it arose in a medium-to-large dog that looked like a husky or Alaskan malamute, and either had a solid black coat or a grizzled one with light and dark bands.
“If we found the bones of that dog somewhere, it would have been considered ancient DNA,” said Murchison. “But its cells are still alive and we’re sequencing its DNA today. It’s mind-boggling.”
Earlier studies predicted that all current CTVTs shared a common ancestor between 250 and ...
