A new 30,000-y-old giant virus infecting Acanthamoeba

[artoar_11]

In-depth study of Mollivirus sibericum, a new 30,000-y-old giant virus infecting Acanthamoeba

Significance

The saga of giant viruses (i.e. visible by light microscopy) started in 2003 with the discovery of Mimivirus. Two additional types of giant viruses infecting Acanthamoeba have been discovered since: the Pandoraviruses (2013) and Pithovirus sibericum (2014), the latter one revived from 30,000-y-old Siberian permafrost. We now describe Mollivirus sibericum, a fourth type of giant virus isolated from the same permafrost sample. These four types of giant virus exhibit different virion structures, sizes (0.6–1.5 µm), genome length (0.6–2.8 Mb), and replication cycles. Their origin and mode of evolution are the subject of conflicting hypotheses. The fact that two different viruses could be easily revived from prehistoric permafrost should be of concern in a context of global warming.