Virus that infects larger virii
A tinsy little virus called "Sputnik" with only 21 genes preys on larger, more developed viruses, infecting them and hijacking their resources to reproduce and spread:
'Virophage' suggests viruses are alive (via /.)With just 21 genes, Sputnik is tiny compared with its mama — but insidious. When the giant mamavirus infects an amoeba, it uses its large array of genes to build a ‘viral factory’, a hub where new viral particles are made. Sputnik infects this viral factory and seems to hijack its machinery in order to replicate. The team found that cells co-infected with Sputnik produce fewer and often deformed mamavirus particles, making the virus less infective. This suggests that Sputnik is effectively a viral parasite that sickens its host — seemingly the first such example.
The team suggests that Sputnik is a ‘virophage’, much like the bacteriophage viruses that infect and sicken bacteria. “It infects this factory like a phage infects a bacterium,” Koonin says. “It’s doing what every parasite can — exploiting its host for its own replication.”
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The title & summary are incorrect- the 'Sputnik' virus does not infect other viruses- it infects microbial cells that have previously been infected with other viruses.
This alone is not new- satellite viruses have been known about for some time.
What's new about this satellite virus is that it inhibits the production of its master virus.
This doesn't really make it a 'virophage', as it doesn't directly attact the master virus in the way that a bacteriophage attacts a bacterial cell.
The New Scientist article on this is (oddly) somewhat better than the Nature one.
Not only that, there's no such word as "virii". The right word is -- big surprise -- "viruses".
At least the headline didn't say you took the picture with your iPhone.
with 21 genes only, can this be engineered to target specific viruses?
“It’s doing what every parasite can — exploiting its host for its own replication.” ... oh, trolls.
maybe the news here is that it's an animal virus? because infection-attenuating satellites happen in some plant viruses, and that's been known for a long time. (I first read about them back in... 1999 I'd say)
#3 I would not think so, since it has to infect cells that are already infected. So there's no benefit to fighting a virus.
#2: I vote we make it an official alternate ... it looks and sounds way cooler and Latin-y:
veni vidi virii -- I came, I saw, I caught a cold
...and so proceed ad infinitum.
#2 - to expand a little. In Latin "virus" is a fourth declension noun, the plural of which in Latin is "virūs" (with a long sounding "u"). Second declension nouns have plurals ending in "i". In any event, the accepted plural in English is "viruses". Here endeth the lesson.
Just because a virus can be weakened (or "sickened") by another virus, does not necessarily mean that viruses are "alive", any more than computers infected with viruses are "alive."
I like to think of viruses as being right on the border between life and non-life, straddling the line, having aspects of both living and nonliving things. Evolution would suggest that at some point non-living molecules get complex enough that they become alive, and the virus is that borderline.
hmm, could this be a potential tool to use against HIV?
Haaz,
I'm thinking no, since HIV is a retrovirus (Rna virus) and these viral victims are "giant viruses", but I'm no expert.
I like the term "mamavirus". I'm sure there's a joke in it somewhere for someone else to find.
It amuses me that new discoveries about viruses are invariably followed by a discussion about what this means for "the debate over whether viruses are alive".
There is no such debate. This is the 21st century. We need not persist with pre-molecular biology essentialist notions like "life" and whether it applies to this system or that. Notably, the authors of the original paper do not once bring up what their discovery means for the life/nonlife status of viruses. That's only added later, by the commentators who dutifully follow the trope.
The "viruses are not alive" dogma is just dogma. In any reasonable sense they are -- they reproduce and evolve. If viruses aren't alive, than virologists are chemists rather than biologists.
NCM #2- and even Slashdot got it right in their headline!
#13, TRR:
'Mamavirus' already is a joke- it's a larger version of a mimivirus.
#15, WNoise:
Viruses do not reproduce. They cannot reproduce themselves at any level without the cellular machinery of their host. They have no metabolism, they are incapable of growth.
They're essentially just a complex trigger to inject genetic material into a host cell- the genetic material then forces the cell to make more copies of the trigger.
If you do think they are alive, you might find it interesting to consider whether prions (self-replicating proteins) are also alive.
viruses, viruses, viruses, viruses, viruses, viruses, viruses, viruses, viruses, viruses, viruses, viruses, viruses, viruses, viruses, viruses, viruses, viruses, viruses, viruses, viruses, viruses, viruses, viruses, viruses, viruses, viruses, viruses, viruses, viruses, viruses, viruses, viruses, viruses.
"If viruses aren't alive, than virologists are chemists rather than biologists."
Wnoise, if virologists *only* studied viruses, they'd really be just biochemists, but since viruses BY THEMSELVES don't do anything, they're always studied in the context of other organisms, so the people who study them are biologists.
I'd say.