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Big parasites have little parasites...
Everyone is probably familiar with thisquote about parasites from Jonathan Swift or some similar quote:
So, naturalists observe, a flea
Hassmaller fleas that on him prey;
And these have smaller still tobite ’em;
And so proceed ad infinitum.
Of course while there are all sorts ofparasites, and parasites of parasites, there ought to be someultimate parasite. Generally we think of viruses as fitting the billbecause they do not carry most of the functions of life that cellsdo. In fact they reproduce by hijacking the host cells replicationmachinery and fool it into making new viruses.
It turns out that at least one giantvirus called a mamavirus has it's own parasite, according to a newsarticle in today's Nature.The mamavirus itself infects amoebas and is called a mamavirusbecause it is a slightly larger version of a kind of virus called amimivirus.The parasite of the mamavirus is another virus dubbed Sputnik and itapparently is carried in association with the mamavirus. When themamavirus infects the amoeba, the Sputnik at some point co-opts themamavirus replication machinery in amoeba and it produces copies ofSputnik along with fewer new mamavirus prticles.
According to the report and thisarticle from the journal Genome Biology, the giant viruses andpresumably their parasites may be common in oceans and be importantin the biology of plankton. So these giant viruses and theirparasites may turn out to have global implications.