The meticulous science behind naming giant viruses
The first giant virus species to have been discovered was christened Mimivirus.
Giant viruses are exceptionally, almost awkwardly large (if I can get away with just one fat virus quip: giant viruses are what other viruses think of when they make yo mama jokes). They can be seen under light microscopes, and get stuck in standard water filters made to keep out bacteria. This already breaks foundational rules of virus definition.
Their discovery is a story unto itself, something that I’ve been itching to blog about but keep putting off. Meanwhile, you can read this nice article from American Scientist and listen to this amazing TWIV podcast episode. That’s not to imply that there’s any non-amazing TWIV podcast episode, because there isn’t. Anyway, I bring this up not to talk about giant viruses or their discovery, but the naming of its first species. Mimivirus.
The people responsible for the name cite two reasons: one, the virus, at least from the perspective of the researchers, were mimicking bacteria. They were first seen inside cells of amoeba, and the fact that they could be seen under light microscopes at all was enough to feed the assumption that they were bacteria. I mean, what else could they have been? On top of that, they took the crystal violet stain that was meant for staining bacterial cells, and appeared gram positive. This was back in 1992, but the virus could only be identified as such in the early 2000’s when someone decided to look at them under an electron microscope and saw the tell-tale regular icosahedral structure characteristic of viral particles. Of course, until that point, Mimivirus frustrated all scientific effort to identify it because they were targeted at characterizing bacteria. Clearly it couldn’t grow on any bacteriological media, nor would it yield 16S DNA for amplification. That explains the name- Mimi, for mimicry.
The second reason is as follows:
[The name was] a tribute to one of our [Didier Raoult] forefathers , who was a doctor who taught tropical medicine and studied nutrition. When teaching his 10-year-old son about evolution, he referred to the last eukaryotic common ancestor as “Mimi the amoeba.”
(If you ask me, after reading this- the mimicry explanation just seems like a post-hoc rationalization)
This naming generated a tiny bit of disapproval, just enough to be fun. On occasion of the discovery of another giant virus species, the Megavirus, the authors relegated a paragraph on “Giant virus naming” in their paper‘s supplementary material, where they point out not only that the name was uninformative, but it also started a tradition of giving giant viruses
…increasingly random/funny names such as “Mamavirus,” “Moumouvirus,” “Courdovirus,” and “Terra”.
Seriously. We were this close to a Memevirus.
I don’t know if their admonition worked or not, since the virus with the largest genome known to date was named Pandoravirus, perhaps to emphasize the “surprises expected from their future study”. Also, Pithovirus is so called because the virus has a thick-walled oval shape:
Evolutionary biologists Jean-Michel Claverie and Chantal Abergel, the husband-and-wife team at Aix-Marseille University in France who led the work, named it Pithovirus sibericum, inspired by the Greek word ‘pithos’ for the large container used by the ancient Greeks to store wine and food. “We’re French, so we had to put wine in the story,” says Claverie.
