Madhuri Raman
March 9th, 2014
No author given
Published: March
4th, 2014
Summary:
Researchers from
the Information Génomique et Structurale laboratory
have recently discovered a giant virus over 30,000 years old in the frozen
ground of Siberia. It is a virus harmless to humans and animals, but infects amoebae. Previously, scientists believed that they had classified
giant viruses into two families: Megaviridae and Pandoravidae. These viruses,
unlike other more common viruses, contain about 2,500 genes while the new
virus, which has been named Pithovirus
sibericum, only has about 500
genes. The
Pandoravirus and the Pithovirus share similar shapes, which led scientists to
believe that they were actually part of the same family. However, they found
that the Pithovirus has about 500 genes in its genome while the Pandoravirus
has over 2500. They also discovered a difference in the viruses' replication
methods inside amoeba cells. The Pandoravirus mainly requires many parts of the
nucleus to replicate, while the Pithovirus mostly replicates in the amoeba's
cytoplasm and is not as reliant on the amoeba's cellular machinery. Overall, the
Pithovirus has been proven to be very different from any previously classified
giant viruses, making it the first member of a new family of viruses, and
bringing the number of virus families to three.
Connection:
This article relates to our class's study of amoebas, viruses, and even classification. In class, we learned about amoebas and their structure. Although only mentioned in the textbook and not in class, we learned about viruses' shapes and their replication mechanism through the Lytic and Lysogenic cycle. The Pithovirus's shape is somewhat different from a normal virus's shape, but it still shared similar properties with other giant viruses. This virus does not directly attack the amoeba's nucleus, and instead replicates itself in the cytoplasm, which is also different from other known viruses. The article also relates to what we have studied about classification because the discovery of this virus led to the formation of a new family of viruses.
