Imagine a virus so big and with genes so different that scientists aren’t sure how it evolved. This is Pandoravirus, and it calls into question everything we think we know about viruses. It was just discovered off the coast of Chile by French biologists Jean-Michel Claverie and Chantal Abergel from Aix-Marseille University. For the full story click here, and check out their paper published 19 July in the journal Science.
So how big is big, and how small is small?
Viruses are the smallest organisms on the planet. They can get away with having few genes and internal components because they rely on the cells of their host to do the hard work. How small is small?
These miniature lifeforms are typically less than a millionth of a metre in size, up to about 0.3 micrometers – so small that scientists have to use special electron microscopes to see them. That is, until the discovery of Pandoravirus, which is a full micrometer in size! So how big is big?
Compared to the common flu virus, Pandoravirus is 1000 times bigger in volume. This means you can see these guys with a regular light microscope. And they’re bigger than some bacteria! Freaky.
What does this all mean?!
Pandoravirus is so named because it opens Pandora’s box for scientists by raising a lot of questions. Organizing lifeforms into lineages based on similarities and differences in their genes tells us how organisms are related, how they originated, and what potential they have for differentiating in the future. In other words, where everything comes from and where it’s going. This is important stuff, especially when trying to predict and prevent pandemics. But these assessments only work when the genes are comparable to those from other organisms.
Pandoravirus has a massive genome with 2.5 million bases (the building blocks of DNA), but only 7% of its genes are recognizable to us. So what’s going on with the other 93% of foreign genes? Support for this research will help scientists get to the bottom of it. In the meantime, there’s speculation that Pandoravirus may have descended from a eukaryotic cell. Hold onto your hat, because this would mean this virus is relative of us humans! The lid to Pandora’s box has indeed been lifted.
Before you run away screaming…
Pandoravirus only attacks amoebas. And although scientists will have to rethink classifications of life to understand this ginormo-virus, we’ll gain new insights into the origins of life, and its strange genes may provide new tools for our biotech and pharmaceutical industries. Pretty damn cool.
–Pandoravirus microscopy images by Chantal Abergel & Jean-Michel Claverie–