Antarctic lake hints at a world of virus-attacking viruses | Not Exactly Rocket Science

Antarctic lake hints at a world of virus-attacking viruses | Not Exactly Rocket Science: "

At first glance, Antarctica’s Organic Lake looks hostile to life. Its water is expectedly cold, extremely salty and starved of oxygen. But look at it under the microscope, and you’ll see teeming masses. There are bacteria and algae. There are viruses that infect the algae. And most astonishing of all, there are viruses attacking the viruses. These are virophages – literally “virus eaters” – and they are third of their kind to be discovered.

The first virophage, known affably as Sputnik, was discovered by Bernard La Scola and Christelle Desnues in 2008. It was an incredible find, and the first time that anyone had seen a virus targeting another virus. La Scola and Desnues found Sputnik in the unlikeliest of places – the dirty water of a Parisian cooling tower. There, it targets one of the world’s largest viruses, known as “mamavirus”, which in turn infects an amoeba.

Mamavirus creates giant viral factories inside the amoeba to make more copies of itself. But Sputnik hijacks these factories, replicating itself at the expense of its larger host. It doesn’t directly infect mamavirus, but it exploits it enough to severely slow its reproduction.

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