PolyDNAVirii

Cassox

Although this isn't something I'm following up on... I find it totally fascinating. So Polydnavirus are TOTALLY contained within the genome of a couple types of wasps. At some point long long ago in a galaxy far away, the virus apparently inserted itself and no longer exists as a unique semi-organism life thing. (Yes, I know the current classification of viruses etc. but after check out mimivirus I'm pretty solid that this will be rewritten/classified before long.)

Point is that a female wasp expressed the virus and uses her ovipositor to infect a lepidoptera larva (think moth larva catepillar things). The virus attacks the immune system of the infectee. As a result, the immune system can't kill the ichneumonid eggs. Dude, there are two different wasps that have formed this relationship with entirely different genera of virii. This is insanely cool. I don't agree with calling this relationship mutualistic even. It's beyond that. It's like the virus is you. 

For biology geeks, this is uber-obviously awesome. If your not erect and bleeding from the nose right now, then I did a poor job explaining how awesome this is. 

DirectorX

What you are explaining is AIDS. Are you saying that the wasp lays eggs in the larvae and injects an HIV-like virus to protect it's eggs from the immune system of the host?

Cassox

Go further. Imagine that you don't have HIV at all. Not a drop in your system... not infected...  but can make it at will to attack your target.

Cassox

Even then, the description falls short because it makes it seem like a poison. Dude, a virus is a totally different "thing." It's not like simply poisoning something. It's more like having the ability to spawn squirrels from you sexual organs who would hold down your enemy so you could beat them. Except, there were no proceeding squirrels. You simply had the DNA of the squirrels waiting within your own DNA.

DirectorX

you had me at spawning squirrels from my genitals. XD
So I'm looking at the mimivirus now and it is really cool, I'm 100% on board with how cool viral stuff is. So these wasps are like typhoid Marys? They carry and can infect without fear of being infected themselves? But technically changes when it enters the target system, right?

aviin

Just did a bit of reading and it sounds like the wasps aren't really carriers in the traditional sense.  They produce the virus in their ovaries only and inject them into the intended egg host along with the egg itself.  The vast majority of the wasp's physiology is completely devoid of the virus.  Very very cool.

TheGreyKnight

Important question: Are humans vulnerable to this virus?

DocMorbid

No, it doesn't appear to be anything but an insect virus.  One interesting thing in relation to humans, however.

"The polyDNAvirus associated with Cotesia rubecula, code for a protein CrV1 that denatures actin filaments..."

As far as the insect goes, this was selected for to prevent encapsulation of the implanted egg.

If I remember histology correctly, it is the actin-myosin complex that is responsible for muscle contraction when binding a calcium ion.  If the CrV1 protein denatures actin, a human virus that coded for this protein would, what, cause muscle paralysis?

Not cool, parasitic AIDS rape wasp.  Well, alright, it is pretty damn cool.

Shaedlaer

That's interesting, though not really unexpected... Considering that research shows that up to 50% of our DNA may be of viral origin, from long-forgotten viri and for big part we have no idea if it does perform any actual function in our bodies or is just 'dead code'...
Considering that mitochondrias in our cells are bacterial cells assimilated into ours far, far down the evolutionary tree, just like chloroplasts in plants, there may be lots of similar examples of symbiosis gone so far that the organisms melded together just waiting to be discovered...

TheGreyKnight

In my experience, and according to the logical application of Natural selection, wouldn't "dead code" have been weeded out by this point? It's a waste of material, space, and cellular processing capabilities, even if it's only a tiny amount.

On that note, it might be interesting to see what kind of practical applications this virus has.

DocMorbid

Non-coding DNA wouldn't necessarily be weeded out.  

Think of it like a subsumption architecture.  A competency may change over time to become more fit, or some other competency may be more fit at the time and suppress the old one.  The old competency, although not active, still remains.  Once in a while, randomly, the old competency becomes active.  If conditions have changed and it is more fit than the newer competency or it can work synergistically with the new competency, then it provides a fitness benefit and should be selected for over time.  If it provides no net change to the organism's fitness, it may still continue to remain active and spread through a population due to genetic drift.

The other possibility is that this non-coding viral genetic material confers an immune benefit.  Obviously, for that DNA to exist, at some point a cell had to become infected and survive.  Perhaps the existence of this viral genome allows some infections to be handled at a cellular level.  Perhaps the viral DNA allows the immune system to more readily recognize these diseases and their more recent variants so that they can be eliminated more readily.  

Sure, a lot of this is conjecture, but if we don't know what something does, we shouldn't dismiss it out of hand.  Note that they often refer to non-coding DNA as appearing to have no function.  That doesn't mean it doesn't have a function - it just means we have no idea what that function could be.  It wasn't that long ago that telomeres were simply considered junk DNA.

glims

look into "dark dna". basically, a lot of what we have considered junk or dead code is just instance specific code. most of it is health related.

DirectorX

K. I read more on polydnavirus. I heart it. I mean, it might be cooler than the prion of love and possibly a better method for mass distribution of the pregnancy contagion. This is sweet.