About a month or so ago, I posted a link on this blog that lead to a new story about Pandoraviruses. Recently, I was able to gain access to the paper that detailed the discovery and unique qualities of these creatures.
Before we can talk about why this discovery is important, we have to talk about the viruses that we have known about for decades. Viruses are generally very small, even to the point of being smaller than most bacteria. They also have genomes (that is their library of genetic information made up of either DNA or RNA depending on the virus) that are relatively small compared to living cells. These qualities were thought to be common to all viruses; until the Mimivirus was discovered.
Mimivirus is a classification of virus that was discovered only recently. These viruses are large, with genomes reaching the size of some bacteria (~1,000,000 base pairs, or 1Mb). Their physical size was at about the same level. In fact, in initial discovery, they were thought to be just another bacteria. It was only when they were examined further that they were found to be only viruses. These particles surprised the scientific community, and, to quote the article, “challenged criteria and protocols historically established to separate viruses from cellular organisms.”
With the discovery of Pandoraviruses, this criteria has been challenged even further. These new viruses are HUGE, both in genome size (~2.2 Mb) and in physical size (~1μm). That may not seem like much, but their genomes are much more advanced than even some eukaryotes. Their size and shape closely resembles bacteria. This discovery certainly blurs the line between living and non-living, and I will be close monitoring for more advancements in the field.