Giant Virus Found In 30000 Year Old Ancient Permafrost
Scientists have uncovered a giant virus in the same sample of 30,000-year-old permafrost that was home to Pithovirus sibericum, the largest virus ever discovered to date.
Since 2003, scientists have found four ancient viruses, suggesting that viruses can be larger and survive for longer periods of time than first thought, writes Science Recorder.
The newly discovered virus, Mollivirus sibericum, is a spherical particle measuring roughly 6 μm in length and containing a genome made of 650,000 base pairs for more than 500 proteins. Mollivirus acts like many small viruses - using the cell nucleus to replicate within the single-celled amoeba it feeds on, making it dependent on its host.
Scientists believe that this family of viruses target amoebae because of the relative ease in which they can be entered. Amoebae feed via a process known as phagocytosis, using their cell membranes to feed on particles and other organisms. In order to enter the amoeba, the giant virus would only need to let itself be eaten. Human and animal cells do not function like amoebas, which has led scientists to believe that the giant virus is not a threat to humans.
"We're not stupid enough to revive a virus that may pose a threat to human health.We use amoeba as bait to fish out whatever viruses may be in that specific sample. But every once in a while, we see them die and that's when we know somebody must be killing them. This way, we know which to isolate from the others," lead researcher Jean-Michel Claverie of France's National Centre for Scientific Research, told the Canada Journal.
However, the researchers will run further tests to confirm that the virus is not dangerous to humans and animals before reviving it to study.
"A few viral particles that are still infectious may be enough, in the presence of a vulnerable host, to revive potentially pathogenic viruses," Claverie said.
This latest discovery suggests that giant viruses are incredibly diverse and potentially not as rare as first thought.
The findings are published in the journal Proceedings of the National Academy of Sciences.