Viruses reproduce by infecting and hijacking other cells, such as ours or bacterial cells – as such, viruses are usually a lot smaller than other cells. However, recently researchers at Aix-Marseille University have found new types of virus known as the Pandoravirus. These viruses are huge compared to normal virus cells and are bigger than some bacteria. They are about 1 micrometre in length compared to classic viruses which are usually only a few tens to hundreds of nanometres, around 10-100 times smaller.
Pandoraviruses have been collected in water samples from Chile and Australia, suggesting they may be widespread and possibly fairly common. They’ve been spotted previously but no one realised they were viruses; they’ve been overlooked due to their huge size which meant they were dismissed by both scientists studying viruses and those studying other microbes. So far little is known about these viruses other than the fact that due to their large size, they probably infect larger cells like amoebas.
These viruses could hold information that could lead to new medicines and energy sources and pretty much anything and everything in biology could be altered by the discovery of the Pandoravirus.
While the discovery of an entirely new type of virus is already shocking for the science community, the biggest news is about the Pandoravirus DNA. Only about 7% of their DNA matches DNA we already know about. When you consider that 98% of our DNA is shared with chimpanzees and around 50% is shared with a banana, finding something that only shares 7% with the entire spectrum of life on this planet is incredible. This means 93% of this virus’s DNA is completely new – completely new biology, new proteins and new ways of healing and protecting itself. These viruses could hold information that could lead to new medicines and energy sources and pretty much anything and everything in biology could be altered by the discovery of the Pandoravirus.
Of course this begs the question of how has something that is 93% different evolved with the rest of life? Did it branch off from other life very early and survive every major extinction event? Did it evolve completely separately to everything else as an entirely different evolutionary tree, making the 7% a fluke or ‘stolen’ DNA down the line? If so, when did this happen? Is this an example of life that has spontaneously formed at a different time to the rest of us? This would make it essentially alien, and since there are theories that life on this planet was transported here on asteroids and meteors, maybe it’s completely alien. But whatever it is, there’s no doubt that it is certainly going to be the focus of a lot of research for a few years to come.
Image: Chantal Abergel and Jean-Michel Claverie