Locked deep in 30,000-year-old Siberian permafrost, a sleeping giant lay in wait — a giant virus, that is. Pithovirus sibericum, a newly discovered giant virus, was still viable when virologists Jean-Michel Claverie and Chantal Abergel thawed the permafrost around it.
Waking P. sibericum marks the first time researchers sidestepped complicated lab techniques typically used to revive dormant viruses. Instead, the team announced in March, they simply warmed the frozen soil and added amoebas, common hosts for giant viruses. Once they observed P. sibericum replicating in its new host, they knew the ancient virus was still viable.
The virus is also physically bigger than members of the Pandoravirus genus, formerly the largest, by about 30 percent. (Yet Pandoraviruses still have bigger genomes than P. sibericum — about 2.5 million base pairs versus P. sibericum’s 600,000 base pairs.) Its resilience raises concern over what other unknown viruses humans might encounter as large-scale mining and drilling projects, not to mention increasingly warm temperatures, thaw more permafrost.