How tiny is tiny?
Sputnik and its mama
Source: science magazine
“So, naturalists observe, a flea
hath smaller fleas that on him prey;
and these have smaller still to bite ‘em;
and so proceed ad infinitum.”
Viruses are usually 20 to 300 nm. That is as tiny as we- an average human being are to the Earth. We are affected by viral fever. We all know that bacteria live in our body at places like the skin, gut etc. Bacteria can be infected with bacteriophages. This has been known to us from a long time now. We now have evidence that viruses also can get infected by smaller viruses.
Two researchers named Chritelle and Bernard la scola found a a giant virus infecting an amoeba cell and also another smaller virus that affects cells infecte by viruses only. They named this small virus after the Russian word Sputnik meaning ‘fellow traveller’. The duo found Sputnik once in 2008 and again now in 2012 in the eye of a women complaining of itching of eyes. To readers with keen interest in this virus, here is the link to the paper: http://www.nature.com/nature/journal/v455/n7209/abs/nature07218.html. Sputnik resides in large viruses called ‘mamaviruses’ that usually invade amoeba cells. These mamviruses make large repositories by replicating themselves. Sputnik conquers these repositories and uses their machinery to replicate itself. This is what I call a ‘smart virus’.
There was a recent discovery of this virus in Antarctica lakes. This virus is particularly of interest to researchers because it is related genetically to three other viruses ergo contradicting the evolution of cells. More information can be found in this article: http://www.pnas.org/content/early/2011/03/24/1018221108
We have been battling the issue of whether viruses are alive or not since they were discovered. Now we have evidence suggesting that they can be infected by other creatures. Are viruses indeed alive? Does it solve the question?