The Shellfish Gene
One strange piece of mobile DNA has spread itself throughout the oceans, claiming real estate in the genomes of clams, fish, and more.
In the late 1970s, scientists noticed that soft-shell clams from Maine were dying from a strange kind of leukemia. Large, cannonball-shaped cancer cells would fill their blood, turning it milky white, and eventually fatally clogging the mollusks’ organs.
For almost 40 years, scientists struggled to work out what was causing the cancer. But once they noticed that the disease seemed to spread from infected clams to uninfected ones, they suspected that a virus might be involved. That’s when Stephen Goff from Columbia University, who studies viruses that cause leukemia in mice, got a call.
